From b36abf2dfcb47cc0ca659c916b3efef9f757ea0c Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 5 Sep 2010 14:50:59 +0200 Subject: hush: big reordering: move parser functions to the beginning. no code changes Signed-off-by: Denys Vlasenko --- shell/hush.c | 8434 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 4217 insertions(+), 4217 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index 1bed721..2afe12f 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -2515,4722 +2515,4722 @@ static char **o_finalize_list(o_string *o, int n) return list; } +static void free_pipe_list(struct pipe *head); -/* Expansion can recurse */ -#if ENABLE_HUSH_TICK -static int process_command_subs(o_string *dest, const char *s); +/* Return code is the exit status of the pipe */ +static void free_pipe(struct pipe *pi) +{ + char **p; + struct command *command; + struct redir_struct *r, *rnext; + int a, i; + + if (pi->stopped_cmds > 0) /* why? */ + return; + debug_printf_clean("run pipe: (pid %d)\n", getpid()); + for (i = 0; i < pi->num_cmds; i++) { + command = &pi->cmds[i]; + debug_printf_clean(" command %d:\n", i); + if (command->argv) { + for (a = 0, p = command->argv; *p; a++, p++) { + debug_printf_clean(" argv[%d] = %s\n", a, *p); + } + free_strings(command->argv); + command->argv = NULL; + } + /* not "else if": on syntax error, we may have both! */ + if (command->group) { + debug_printf_clean(" begin group (cmd_type:%d)\n", + command->cmd_type); + free_pipe_list(command->group); + debug_printf_clean(" end group\n"); + command->group = NULL; + } + /* else is crucial here. + * If group != NULL, child_func is meaningless */ +#if ENABLE_HUSH_FUNCTIONS + else if (command->child_func) { + debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func); + command->child_func->parent_cmd = NULL; + } #endif -static char *expand_string_to_string(const char *str); -#if BB_MMU -#define parse_stream_dquoted(as_string, dest, input, dquote_end) \ - parse_stream_dquoted(dest, input, dquote_end) +#if !BB_MMU + free(command->group_as_string); + command->group_as_string = NULL; #endif -static int parse_stream_dquoted(o_string *as_string, - o_string *dest, - struct in_str *input, - int dquote_end); - -/* expand_strvec_to_strvec() takes a list of strings, expands - * all variable references within and returns a pointer to - * a list of expanded strings, possibly with larger number - * of strings. (Think VAR="a b"; echo $VAR). - * This new list is allocated as a single malloc block. - * NULL-terminated list of char* pointers is at the beginning of it, - * followed by strings themself. - * Caller can deallocate entire list by single free(list). */ - -/* Store given string, finalizing the word and starting new one whenever - * we encounter IFS char(s). This is used for expanding variable values. - * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ -static int expand_on_ifs(o_string *output, int n, const char *str) -{ - while (1) { - int word_len = strcspn(str, G.ifs); - if (word_len) { - if (output->o_escape || !output->o_glob) - o_addQblock(output, str, word_len); - else /* protect backslashes against globbing up :) */ - o_addblock_duplicate_backslash(output, str, word_len); - str += word_len; + for (r = command->redirects; r; r = rnext) { + debug_printf_clean(" redirect %d%s", + r->rd_fd, redir_table[r->rd_type].descrip); + /* guard against the case >$FOO, where foo is unset or blank */ + if (r->rd_filename) { + debug_printf_clean(" fname:'%s'\n", r->rd_filename); + free(r->rd_filename); + r->rd_filename = NULL; + } + debug_printf_clean(" rd_dup:%d\n", r->rd_dup); + rnext = r->next; + free(r); } - if (!*str) /* EOL - do not finalize word */ - break; - o_addchr(output, '\0'); - debug_print_list("expand_on_ifs", output, n); - n = o_save_ptr(output, n); - str += strspn(str, G.ifs); /* skip ifs chars */ + command->redirects = NULL; } - debug_print_list("expand_on_ifs[1]", output, n); - return n; + free(pi->cmds); /* children are an array, they get freed all at once */ + pi->cmds = NULL; +#if ENABLE_HUSH_JOB + free(pi->cmdtext); + pi->cmdtext = NULL; +#endif } -/* Helper to expand $((...)) and heredoc body. These act as if - * they are in double quotes, with the exception that they are not :). - * Just the rules are similar: "expand only $var and `cmd`" - * - * Returns malloced string. - * As an optimization, we return NULL if expansion is not needed. - */ -static char *expand_pseudo_dquoted(const char *str) +static void free_pipe_list(struct pipe *head) { - char *exp_str; - struct in_str input; - o_string dest = NULL_O_STRING; + struct pipe *pi, *next; - if (!strchr(str, '$') -#if ENABLE_HUSH_TICK - && !strchr(str, '`') + for (pi = head; pi; pi = next) { +#if HAS_KEYWORDS + debug_printf_clean(" pipe reserved word %d\n", pi->res_word); #endif - ) { - return NULL; + free_pipe(pi); + debug_printf_clean("pipe followup code %d\n", pi->followup); + next = pi->next; + /*pi->next = NULL;*/ + free(pi); } - - /* We need to expand. Example: - * echo $(($a + `echo 1`)) $((1 + $((2)) )) - */ - setup_string_in_str(&input, str); - parse_stream_dquoted(NULL, &dest, &input, EOF); - //bb_error_msg("'%s' -> '%s'", str, dest.data); - exp_str = expand_string_to_string(dest.data); - //bb_error_msg("'%s' -> '%s'", dest.data, exp_str); - o_free_unsafe(&dest); - return exp_str; } -#if ENABLE_SH_MATH_SUPPORT -static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p) -{ - arith_eval_hooks_t hooks; - arith_t res; - char *exp_str; - hooks.lookupvar = get_local_var_value; - hooks.setvar = set_local_var_from_halves; - hooks.endofname = endofname; - exp_str = expand_pseudo_dquoted(arg); - res = arith(exp_str ? exp_str : arg, errcode_p, &hooks); - free(exp_str); - return res; -} -#endif +/*** Parsing routines ***/ -#if ENABLE_HUSH_BASH_COMPAT -/* ${var/[/]pattern[/repl]} helpers */ -static char *strstr_pattern(char *val, const char *pattern, int *size) +static struct pipe *new_pipe(void) { - while (1) { - char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF); - debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end); - if (end) { - *size = end - val; - return val; - } - if (*val == '\0') - return NULL; - /* Optimization: if "*pat" did not match the start of "string", - * we know that "tring", "ring" etc will not match too: - */ - if (pattern[0] == '*') - return NULL; - val++; - } + struct pipe *pi; + pi = xzalloc(sizeof(struct pipe)); + /*pi->followup = 0; - deliberately invalid value */ + /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */ + return pi; } -static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op) -{ - char *result = NULL; - unsigned res_len = 0; - unsigned repl_len = strlen(repl); - - while (1) { - int size; - char *s = strstr_pattern(val, pattern, &size); - if (!s) - break; - result = xrealloc(result, res_len + (s - val) + repl_len + 1); - memcpy(result + res_len, val, s - val); - res_len += s - val; - strcpy(result + res_len, repl); - res_len += repl_len; - debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result); +/* Command (member of a pipe) is complete, or we start a new pipe + * if ctx->command is NULL. + * No errors possible here. + */ +static int done_command(struct parse_context *ctx) +{ + /* The command is really already in the pipe structure, so + * advance the pipe counter and make a new, null command. */ + struct pipe *pi = ctx->pipe; + struct command *command = ctx->command; - val = s + size; - if (exp_op == '/') - break; - } - if (val[0] && result) { - result = xrealloc(result, res_len + strlen(val) + 1); - strcpy(result + res_len, val); - debug_printf_varexp("val:'%s' result:'%s'\n", val, result); + if (command) { + if (IS_NULL_CMD(command)) { + debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); + goto clear_and_ret; + } + pi->num_cmds++; + debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); + //debug_print_tree(ctx->list_head, 20); + } else { + debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); } - debug_printf_varexp("result:'%s'\n", result); - return result; + + /* Only real trickiness here is that the uncommitted + * command structure is not counted in pi->num_cmds. */ + pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1)); + ctx->command = command = &pi->cmds[pi->num_cmds]; + clear_and_ret: + memset(command, 0, sizeof(*command)); + return pi->num_cmds; /* used only for 0/nonzero check */ } -#endif -/* Helper: - * Handles varname... construct. - */ -static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp, char first_ch) +static void done_pipe(struct parse_context *ctx, pipe_style type) { - const char *val = NULL; - char *to_be_freed = NULL; - char *p = *pp; - char *var; - char first_char; - char exp_op; - char exp_save = exp_save; /* for compiler */ - char *exp_saveptr; /* points to expansion operator */ - char *exp_word = exp_word; /* for compiler */ - - var = arg; - *p = '\0'; - exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL; - first_char = arg[0] = first_ch & 0x7f; - exp_op = 0; + int not_null; - if (first_char == '#' && arg[1] && !exp_saveptr) { - /* handle length expansion ${#var} */ - var++; - exp_op = 'L'; - } else { - /* maybe handle parameter expansion */ - if (exp_saveptr /* if 2nd char is one of expansion operators */ - && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */ - ) { - /* ${?:0}, ${#[:]%0} etc */ - exp_saveptr = var + 1; - } else { - /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */ - exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS); - } - exp_op = exp_save = *exp_saveptr; - if (exp_op) { - exp_word = exp_saveptr + 1; - if (exp_op == ':') { - exp_op = *exp_word++; - if (ENABLE_HUSH_BASH_COMPAT - && (exp_op == '\0' || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op)) - ) { - /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */ - exp_op = ':'; - exp_word--; - } - } - *exp_saveptr = '\0'; - } /* else: it's not an expansion op, but bare ${var} */ - } - - /* lookup the variable in question */ - if (isdigit(var[0])) { - /* parse_dollar() should have vetted var for us */ - int n = xatoi_positive(var); - if (n < G.global_argc) - val = G.global_argv[n]; - /* else val remains NULL: $N with too big N */ - } else { - switch (var[0]) { - case '$': /* pid */ - val = utoa(G.root_pid); - break; - case '!': /* bg pid */ - val = G.last_bg_pid ? utoa(G.last_bg_pid) : ""; - break; - case '?': /* exitcode */ - val = utoa(G.last_exitcode); - break; - case '#': /* argc */ - val = utoa(G.global_argc ? G.global_argc-1 : 0); - break; - default: - val = get_local_var_value(var); - } - } - - /* Handle any expansions */ - if (exp_op == 'L') { - debug_printf_expand("expand: length(%s)=", val); - val = utoa(val ? strlen(val) : 0); - debug_printf_expand("%s\n", val); - } else if (exp_op) { - if (exp_op == '%' || exp_op == '#') { - /* Standard-mandated substring removal ops: - * ${parameter%word} - remove smallest suffix pattern - * ${parameter%%word} - remove largest suffix pattern - * ${parameter#word} - remove smallest prefix pattern - * ${parameter##word} - remove largest prefix pattern - * - * Word is expanded to produce a glob pattern. - * Then var's value is matched to it and matching part removed. - */ - if (val && val[0]) { - char *exp_exp_word; - char *loc; - unsigned scan_flags = pick_scan(exp_op, *exp_word); - if (exp_op == *exp_word) /* ## or %% */ - exp_word++; -//TODO: avoid xstrdup unless needed -// (see HACK ALERT below) - val = to_be_freed = xstrdup(val); - exp_exp_word = expand_pseudo_dquoted(exp_word); - if (exp_exp_word) - exp_word = exp_exp_word; - loc = scan_and_match(to_be_freed, exp_word, scan_flags); - //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'", - // exp_op, to_be_freed, exp_word, loc); - free(exp_exp_word); - if (loc) { /* match was found */ - if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */ - val = loc; - else /* %[%] */ - *loc = '\0'; - } - } - } -#if ENABLE_HUSH_BASH_COMPAT - else if (exp_op == '/' || exp_op == '\\') { - /* Empty variable always gives nothing: */ - // "v=''; echo ${v/*/w}" prints "" - if (val && val[0]) { - /* It's ${var/[/]pattern[/repl]} thing */ - char *pattern, *repl, *t; - pattern = expand_pseudo_dquoted(exp_word); - if (!pattern) - pattern = xstrdup(exp_word); - debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern); - *p++ = SPECIAL_VAR_SYMBOL; - exp_word = p; - p = strchr(p, SPECIAL_VAR_SYMBOL); - *p = '\0'; - repl = expand_pseudo_dquoted(exp_word); - debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl); - /* HACK ALERT. We depend here on the fact that - * G.global_argv and results of utoa and get_local_var_value - * are actually in writable memory: - * replace_pattern momentarily stores NULs there. */ - t = (char*)val; - to_be_freed = replace_pattern(t, - pattern, - (repl ? repl : exp_word), - exp_op); - if (to_be_freed) /* at least one replace happened */ - val = to_be_freed; - free(pattern); - free(repl); - } - } -#endif - else if (exp_op == ':') { -#if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT - /* It's ${var:N[:M]} bashism. - * Note that in encoded form it has TWO parts: - * var:NM - */ - arith_t beg, len; - int errcode = 0; - - beg = expand_and_evaluate_arith(exp_word, &errcode); - debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg); - *p++ = SPECIAL_VAR_SYMBOL; - exp_word = p; - p = strchr(p, SPECIAL_VAR_SYMBOL); - *p = '\0'; - len = expand_and_evaluate_arith(exp_word, &errcode); - debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len); - - if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */ - if (beg < 0) /* bash compat */ - beg = 0; - debug_printf_varexp("from val:'%s'\n", val); - if (len == 0 || !val || beg >= strlen(val)) - val = ""; - else { - /* Paranoia. What if user entered 9999999999999 - * which fits in arith_t but not int? */ - if (len >= INT_MAX) - len = INT_MAX; - val = to_be_freed = xstrndup(val + beg, len); - } - debug_printf_varexp("val:'%s'\n", val); - } else -#endif - { - die_if_script("malformed ${%s:...}", var); - val = ""; - } - } else { /* one of "-=+?" */ - /* Standard-mandated substitution ops: - * ${var?word} - indicate error if unset - * If var is unset, word (or a message indicating it is unset - * if word is null) is written to standard error - * and the shell exits with a non-zero exit status. - * Otherwise, the value of var is substituted. - * ${var-word} - use default value - * If var is unset, word is substituted. - * ${var=word} - assign and use default value - * If var is unset, word is assigned to var. - * In all cases, final value of var is substituted. - * ${var+word} - use alternative value - * If var is unset, null is substituted. - * Otherwise, word is substituted. - * - * Word is subjected to tilde expansion, parameter expansion, - * command substitution, and arithmetic expansion. - * If word is not needed, it is not expanded. - * - * Colon forms (${var:-word}, ${var:=word} etc) do the same, - * but also treat null var as if it is unset. - */ - int use_word = (!val || ((exp_save == ':') && !val[0])); - if (exp_op == '+') - use_word = !use_word; - debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op, - (exp_save == ':') ? "true" : "false", use_word); - if (use_word) { - to_be_freed = expand_pseudo_dquoted(exp_word); - if (to_be_freed) - exp_word = to_be_freed; - if (exp_op == '?') { - /* mimic bash message */ - die_if_script("%s: %s", - var, - exp_word[0] ? exp_word : "parameter null or not set" - ); -//TODO: how interactive bash aborts expansion mid-command? - } else { - val = exp_word; - } - - if (exp_op == '=') { - /* ${var=[word]} or ${var:=[word]} */ - if (isdigit(var[0]) || var[0] == '#') { - /* mimic bash message */ - die_if_script("$%s: cannot assign in this way", var); - val = NULL; - } else { - char *new_var = xasprintf("%s=%s", var, val); - set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); - } - } - } - } /* one of "-=+?" */ - - *exp_saveptr = exp_save; - } /* if (exp_op) */ - - arg[0] = first_ch; - - *pp = p; - *to_be_freed_pp = to_be_freed; - return val; -} - -/* Expand all variable references in given string, adding words to list[] - * at n, n+1,... positions. Return updated n (so that list[n] is next one - * to be filled). This routine is extremely tricky: has to deal with - * variables/parameters with whitespace, $* and $@, and constructs like - * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ -static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) -{ - /* or_mask is either 0 (normal case) or 0x80 - - * expansion of right-hand side of assignment == 1-element expand. - * It will also do no globbing, and thus we must not backslash-quote! - */ - char ored_ch; - char *p; - - ored_ch = 0; - - debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask); - debug_print_list("expand_vars_to_list", output, n); - n = o_save_ptr(output, n); - debug_print_list("expand_vars_to_list[0]", output, n); - - while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { - char first_ch; - int i; - char *to_be_freed = NULL; - const char *val = NULL; -#if ENABLE_HUSH_TICK - o_string subst_result = NULL_O_STRING; -#endif -#if ENABLE_SH_MATH_SUPPORT - char arith_buf[sizeof(arith_t)*3 + 2]; + debug_printf_parse("done_pipe entered, followup %d\n", type); + /* Close previous command */ + not_null = done_command(ctx); + ctx->pipe->followup = type; +#if HAS_KEYWORDS + ctx->pipe->pi_inverted = ctx->ctx_inverted; + ctx->ctx_inverted = 0; + ctx->pipe->res_word = ctx->ctx_res_w; #endif - o_addblock(output, arg, p - arg); - debug_print_list("expand_vars_to_list[1]", output, n); - arg = ++p; - p = strchr(p, SPECIAL_VAR_SYMBOL); - first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ - /* "$@" is special. Even if quoted, it can still - * expand to nothing (not even an empty string) */ - if ((first_ch & 0x7f) != '@') - ored_ch |= first_ch; - - switch (first_ch & 0x7f) { - /* Highest bit in first_ch indicates that var is double-quoted */ - case '*': - case '@': - i = 1; - if (!G.global_argv[i]) - break; - ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ - if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ - smallint sv = output->o_escape; - /* unquoted var's contents should be globbed, so don't escape */ - output->o_escape = 0; - while (G.global_argv[i]) { - n = expand_on_ifs(output, n, G.global_argv[i]); - debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); - if (G.global_argv[i++][0] && G.global_argv[i]) { - /* this argv[] is not empty and not last: - * put terminating NUL, start new word */ - o_addchr(output, '\0'); - debug_print_list("expand_vars_to_list[2]", output, n); - n = o_save_ptr(output, n); - debug_print_list("expand_vars_to_list[3]", output, n); - } - } - output->o_escape = sv; - } else - /* If or_mask is nonzero, we handle assignment 'a=....$@.....' - * and in this case should treat it like '$*' - see 'else...' below */ - if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ - while (1) { - o_addQstr(output, G.global_argv[i]); - if (++i >= G.global_argc) - break; - o_addchr(output, '\0'); - debug_print_list("expand_vars_to_list[4]", output, n); - n = o_save_ptr(output, n); - } - } else { /* quoted $*: add as one word */ - while (1) { - o_addQstr(output, G.global_argv[i]); - if (!G.global_argv[++i]) - break; - if (G.ifs[0]) - o_addchr(output, G.ifs[0]); - } - } - break; - case SPECIAL_VAR_SYMBOL: /* */ - /* "Empty variable", used to make "" etc to not disappear */ - arg++; - ored_ch = 0x80; - break; -#if ENABLE_HUSH_TICK - case '`': /* `cmd */ - *p = '\0'; - arg++; - /* Can't just stuff it into output o_string, - * expanded result may need to be globbed - * and $IFS-splitted */ - debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); - G.last_exitcode = process_command_subs(&subst_result, arg); - debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data); - val = subst_result.data; - goto store_val; + /* Without this check, even just on command line generates + * tree of three NOPs (!). Which is harmless but annoying. + * IOW: it is safe to do it unconditionally. */ + if (not_null +#if ENABLE_HUSH_IF + || ctx->ctx_res_w == RES_FI #endif -#if ENABLE_SH_MATH_SUPPORT - case '+': { /* +cmd */ - arith_t res; - int errcode; - - arg++; /* skip '+' */ - *p = '\0'; /* replace trailing */ - debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch); - res = expand_and_evaluate_arith(arg, &errcode); - - if (errcode < 0) { - const char *msg = "error in arithmetic"; - switch (errcode) { - case -3: - msg = "exponent less than 0"; - break; - case -2: - msg = "divide by 0"; - break; - case -5: - msg = "expression recursion loop detected"; - break; - } - die_if_script(msg); - } - debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res); - sprintf(arith_buf, arith_t_fmt, res); - val = arith_buf; - break; - } +#if ENABLE_HUSH_LOOPS + || ctx->ctx_res_w == RES_DONE + || ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN #endif - default: - val = expand_one_var(&to_be_freed, arg, &p, first_ch); - IF_HUSH_TICK(store_val:) - if (!(first_ch & 0x80)) { /* unquoted $VAR */ - debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape); - if (val && val[0]) { - /* unquoted var's contents should be globbed, so don't escape */ - smallint sv = output->o_escape; - output->o_escape = 0; - n = expand_on_ifs(output, n, val); - val = NULL; - output->o_escape = sv; - } - } else { /* quoted $VAR, val will be appended below */ - debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape); - } - break; - - } /* switch (char after ) */ - - if (val && val[0]) { - o_addQstr(output, val); - } - free(to_be_freed); - /* Do the check to avoid writing to a const string */ - if (*p != SPECIAL_VAR_SYMBOL) - *p = SPECIAL_VAR_SYMBOL; - -#if ENABLE_HUSH_TICK - o_free(&subst_result); +#if ENABLE_HUSH_CASE + || ctx->ctx_res_w == RES_ESAC #endif - arg = ++p; - } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ - - if (arg[0]) { - debug_print_list("expand_vars_to_list[a]", output, n); - /* this part is literal, and it was already pre-quoted - * if needed (much earlier), do not use o_addQstr here! */ - o_addstr_with_NUL(output, arg); - debug_print_list("expand_vars_to_list[b]", output, n); - } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ - && !(ored_ch & 0x80) /* and all vars were not quoted. */ ) { - n--; - /* allow to reuse list[n] later without re-growth */ - output->has_empty_slot = 1; - } else { - o_addchr(output, '\0'); - } - - return n; -} - -enum { - EXPVAR_FLAG_GLOB = 0x200, - EXPVAR_FLAG_ESCAPE_VARS = 0x100, - EXPVAR_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */ -}; -static char **expand_variables(char **argv, unsigned or_mask) -{ - int n; - char **list; - char **v; - o_string output = NULL_O_STRING; - - /* protect against globbing for "$var"? */ - /* (unquoted $var will temporarily switch it off) */ - output.o_escape = 1 & (or_mask / EXPVAR_FLAG_ESCAPE_VARS); - output.o_glob = 1 & (or_mask / EXPVAR_FLAG_GLOB); - - n = 0; - v = argv; - while (*v) { - n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask); - v++; - } - debug_print_list("expand_variables", &output, n); - - /* output.data (malloced in one block) gets returned in "list" */ - list = o_finalize_list(&output, n); - debug_print_strings("expand_variables[1]", list); - return list; -} - -static char **expand_strvec_to_strvec(char **argv) -{ - return expand_variables(argv, EXPVAR_FLAG_GLOB | EXPVAR_FLAG_ESCAPE_VARS); -} - -#if ENABLE_HUSH_BASH_COMPAT -static char **expand_strvec_to_strvec_singleword_noglob(char **argv) -{ - return expand_variables(argv, EXPVAR_FLAG_SINGLEWORD); -} + struct pipe *new_p; + debug_printf_parse("done_pipe: adding new pipe: " + "not_null:%d ctx->ctx_res_w:%d\n", + not_null, ctx->ctx_res_w); + new_p = new_pipe(); + ctx->pipe->next = new_p; + ctx->pipe = new_p; + /* RES_THEN, RES_DO etc are "sticky" - + * they remain set for pipes inside if/while. + * This is used to control execution. + * RES_FOR and RES_IN are NOT sticky (needed to support + * cases where variable or value happens to match a keyword): + */ +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN) + ctx->ctx_res_w = RES_NONE; #endif - -#ifdef CMD_SINGLEWORD_NOGLOB_COND -static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv) -{ - int n; - char **list; - char **v; - o_string output = NULL_O_STRING; - - n = 0; - v = argv; - while (*v) { - int is_var = is_well_formed_var_name(*v, '='); - /* is_var * 0x80: singleword expansion for vars */ - n = expand_vars_to_list(&output, n, *v, is_var * 0x80); - - /* Subtle! expand_vars_to_list did not glob last word yet. - * It does this only when fed with further data. - * Therefore we set globbing flags AFTER it, not before: +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + ctx->ctx_res_w = RES_CASE_BODY; + if (ctx->ctx_res_w == RES_CASE) + ctx->ctx_res_w = RES_CASE_IN; +#endif + ctx->command = NULL; /* trick done_command below */ + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; */ - - /* if it is not recognizably abc=...; then: */ - output.o_escape = !is_var; /* protect against globbing for "$var" */ - /* (unquoted $var will temporarily switch it off) */ - output.o_glob = !is_var; /* and indeed do globbing */ - v++; + done_command(ctx); + //debug_print_tree(ctx->list_head, 10); } - debug_print_list("expand_cond", &output, n); - - /* output.data (malloced in one block) gets returned in "list" */ - list = o_finalize_list(&output, n); - debug_print_strings("expand_cond[1]", list); - return list; + debug_printf_parse("done_pipe return\n"); } -#endif -/* Used for expansion of right hand of assignments */ -/* NB: should NOT do globbing! - * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*" */ -static char *expand_string_to_string(const char *str) +static void initialize_context(struct parse_context *ctx) { - char *argv[2], **list; - - /* This is generally an optimization, but it also - * handles "", which otherwise trips over !list[0] check below. - * (is this ever happens that we actually get str="" here?) + memset(ctx, 0, sizeof(*ctx)); + ctx->pipe = ctx->list_head = new_pipe(); + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; */ - if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) { - //TODO: Can use on strings with \ too, just unbackslash() them? - debug_printf_expand("string_to_string(fast)='%s'\n", str); - return xstrdup(str); - } - - argv[0] = (char*)str; - argv[1] = NULL; - list = expand_variables(argv, EXPVAR_FLAG_ESCAPE_VARS | EXPVAR_FLAG_SINGLEWORD); - if (HUSH_DEBUG) - if (!list[0] || list[1]) - bb_error_msg_and_die("BUG in varexp2"); - /* actually, just move string 2*sizeof(char*) bytes back */ - overlapping_strcpy((char*)list, list[0]); - unbackslash((char*)list); - debug_printf_expand("string_to_string='%s'\n", (char*)list); - return (char*)list; + done_command(ctx); } -/* Used for "eval" builtin */ -static char* expand_strvec_to_string(char **argv) -{ - char **list; - - list = expand_variables(argv, EXPVAR_FLAG_SINGLEWORD); - /* Convert all NULs to spaces */ - if (list[0]) { - int n = 1; - while (list[n]) { - if (HUSH_DEBUG) - if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) - bb_error_msg_and_die("BUG in varexp3"); - /* bash uses ' ' regardless of $IFS contents */ - list[n][-1] = ' '; - n++; - } - } - overlapping_strcpy((char*)list, list[0]); - debug_printf_expand("strvec_to_string='%s'\n", (char*)list); - return (char*)list; -} +/* If a reserved word is found and processed, parse context is modified + * and 1 is returned. + */ +#if HAS_KEYWORDS +struct reserved_combo { + char literal[6]; + unsigned char res; + unsigned char assignment_flag; + int flag; +}; +enum { + FLAG_END = (1 << RES_NONE ), +# if ENABLE_HUSH_IF + FLAG_IF = (1 << RES_IF ), + FLAG_THEN = (1 << RES_THEN ), + FLAG_ELIF = (1 << RES_ELIF ), + FLAG_ELSE = (1 << RES_ELSE ), + FLAG_FI = (1 << RES_FI ), +# endif +# if ENABLE_HUSH_LOOPS + FLAG_FOR = (1 << RES_FOR ), + FLAG_WHILE = (1 << RES_WHILE), + FLAG_UNTIL = (1 << RES_UNTIL), + FLAG_DO = (1 << RES_DO ), + FLAG_DONE = (1 << RES_DONE ), + FLAG_IN = (1 << RES_IN ), +# endif +# if ENABLE_HUSH_CASE + FLAG_MATCH = (1 << RES_MATCH), + FLAG_ESAC = (1 << RES_ESAC ), +# endif + FLAG_START = (1 << RES_XXXX ), +}; -static char **expand_assignments(char **argv, int count) +static const struct reserved_combo* match_reserved_word(o_string *word) { - int i; - char **p; + /* Mostly a list of accepted follow-up reserved words. + * FLAG_END means we are done with the sequence, and are ready + * to turn the compound list into a command. + * FLAG_START means the word must start a new compound list. + */ + static const struct reserved_combo reserved_list[] = { +# if ENABLE_HUSH_IF + { "!", RES_NONE, NOT_ASSIGNMENT , 0 }, + { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START }, + { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, + { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN }, + { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI }, + { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END }, +# endif +# if ENABLE_HUSH_LOOPS + { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START }, + { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO }, + { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE }, + { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END }, +# endif +# if ENABLE_HUSH_CASE + { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START }, + { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END }, +# endif + }; + const struct reserved_combo *r; - G.expanded_assignments = p = NULL; - /* Expand assignments into one string each */ - for (i = 0; i < count; i++) { - G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i])); + for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { + if (strcmp(word->data, r->literal) == 0) + return r; } - G.expanded_assignments = NULL; - return p; + return NULL; } - - -#if BB_MMU -/* never called */ -void re_execute_shell(char ***to_free, const char *s, - char *g_argv0, char **g_argv, - char **builtin_argv) NORETURN; - -static void reset_traps_to_defaults(void) +/* Return 0: not a keyword, 1: keyword + */ +static int reserved_word(o_string *word, struct parse_context *ctx) { - /* This function is always called in a child shell - * after fork (not vfork, NOMMU doesn't use this function). - */ - unsigned sig; - unsigned mask; +# if ENABLE_HUSH_CASE + static const struct reserved_combo reserved_match = { + "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC + }; +# endif + const struct reserved_combo *r; - /* Child shells are not interactive. - * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. - * Testcase: (while :; do :; done) + ^Z should background. - * Same goes for SIGTERM, SIGHUP, SIGINT. - */ - if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS)) - return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */ + if (word->has_quoted_part) + return 0; + r = match_reserved_word(word); + if (!r) + return 0; - /* Switching off SPECIAL_INTERACTIVE_SIGS. - * Stupid. It can be done with *single* &= op, but we can't use - * the fact that G.blocked_set is implemented as a bitmask - * in libc... */ - mask = (SPECIAL_INTERACTIVE_SIGS >> 1); - sig = 1; - while (1) { - if (mask & 1) { - /* Careful. Only if no trap or trap is not "" */ - if (!G.traps || !G.traps[sig] || G.traps[sig][0]) - sigdelset(&G.blocked_set, sig); + debug_printf("found reserved word %s, res %d\n", r->literal, r->res); +# if ENABLE_HUSH_CASE + if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) { + /* "case word IN ..." - IN part starts first MATCH part */ + r = &reserved_match; + } else +# endif + if (r->flag == 0) { /* '!' */ + if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */ + syntax_error("! ! command"); + ctx->ctx_res_w = RES_SNTX; } - mask >>= 1; - if (!mask) - break; - sig++; + ctx->ctx_inverted = 1; + return 1; + } + if (r->flag & FLAG_START) { + struct parse_context *old; + + old = xmalloc(sizeof(*old)); + debug_printf_parse("push stack %p\n", old); + *old = *ctx; /* physical copy */ + initialize_context(ctx); + ctx->stack = old; + } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) { + syntax_error_at(word->data); + ctx->ctx_res_w = RES_SNTX; + return 1; + } else { + /* "{...} fi" is ok. "{...} if" is not + * Example: + * if { echo foo; } then { echo bar; } fi */ + if (ctx->command->group) + done_pipe(ctx, PIPE_SEQ); } - /* Our homegrown sig mask is saner to work with :) */ - G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS; - /* Resetting all traps to default except empty ones */ - mask = G.non_DFL_mask; - if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) { - if (!G.traps[sig] || !G.traps[sig][0]) - continue; - free(G.traps[sig]); - G.traps[sig] = NULL; - /* There is no signal for 0 (EXIT) */ - if (sig == 0) - continue; - /* There was a trap handler, we just removed it. - * But if sig still has non-DFL handling, - * we should not unblock the sig. */ - if (mask & 1) - continue; - sigdelset(&G.blocked_set, sig); + ctx->ctx_res_w = r->res; + ctx->old_flag = r->flag; + word->o_assignment = r->assignment_flag; + + if (ctx->old_flag & FLAG_END) { + struct parse_context *old; + + done_pipe(ctx, PIPE_SEQ); + debug_printf_parse("pop stack %p\n", ctx->stack); + old = ctx->stack; + old->command->group = ctx->list_head; + old->command->cmd_type = CMD_NORMAL; +# if !BB_MMU + o_addstr(&old->as_string, ctx->as_string.data); + o_free_unsafe(&ctx->as_string); + old->command->group_as_string = xstrdup(old->as_string.data); + debug_printf_parse("pop, remembering as:'%s'\n", + old->command->group_as_string); +# endif + *ctx = *old; /* physical copy */ + free(old); } - sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); + return 1; } +#endif /* HAS_KEYWORDS */ -#else /* !BB_MMU */ - -static void re_execute_shell(char ***to_free, const char *s, - char *g_argv0, char **g_argv, - char **builtin_argv) NORETURN; -static void re_execute_shell(char ***to_free, const char *s, - char *g_argv0, char **g_argv, - char **builtin_argv) +/* Word is complete, look at it and update parsing context. + * Normal return is 0. Syntax errors return 1. + * Note: on return, word is reset, but not o_free'd! + */ +static int done_word(o_string *word, struct parse_context *ctx) { -# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x")) - /* delims + 2 * (number of bytes in printed hex numbers) */ - char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)]; - char *heredoc_argv[4]; - struct variable *cur; -# if ENABLE_HUSH_FUNCTIONS - struct function *funcp; -# endif - char **argv, **pp; - unsigned cnt; - unsigned long long empty_trap_mask; + struct command *command = ctx->command; - if (!g_argv0) { /* heredoc */ - argv = heredoc_argv; - argv[0] = (char *) G.argv0_for_re_execing; - argv[1] = (char *) "-<"; - argv[2] = (char *) s; - argv[3] = NULL; - pp = &argv[3]; /* used as pointer to empty environment */ - goto do_exec; + debug_printf_parse("done_word entered: '%s' %p\n", word->data, command); + if (word->length == 0 && !word->has_quoted_part) { + debug_printf_parse("done_word return 0: true null, ignored\n"); + return 0; } - cnt = 0; - pp = builtin_argv; - if (pp) while (*pp++) - cnt++; + if (ctx->pending_redirect) { + /* We do not glob in e.g. >*.tmp case. bash seems to glob here + * only if run as "bash", not "sh" */ + /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html + * "2.7 Redirection + * ...the word that follows the redirection operator + * shall be subjected to tilde expansion, parameter expansion, + * command substitution, arithmetic expansion, and quote + * removal. Pathname expansion shall not be performed + * on the word by a non-interactive shell; an interactive + * shell may perform it, but shall do so only when + * the expansion would result in one word." + */ + ctx->pending_redirect->rd_filename = xstrdup(word->data); + /* Cater for >\file case: + * >\a creates file a; >\\a, >"\a", >"\\a" create file \a + * Same with heredocs: + * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H + */ + if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) { + unbackslash(ctx->pending_redirect->rd_filename); + /* Is it <<"HEREDOC"? */ + if (word->has_quoted_part) { + ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED; + } + } + debug_printf_parse("word stored in rd_filename: '%s'\n", word->data); + ctx->pending_redirect = NULL; + } else { + /* If this word wasn't an assignment, next ones definitely + * can't be assignments. Even if they look like ones. */ + if (word->o_assignment != DEFINITELY_ASSIGNMENT + && word->o_assignment != WORD_IS_KEYWORD + ) { + word->o_assignment = NOT_ASSIGNMENT; + } else { + if (word->o_assignment == DEFINITELY_ASSIGNMENT) + command->assignment_cnt++; + word->o_assignment = MAYBE_ASSIGNMENT; + } - empty_trap_mask = 0; - if (G.traps) { - int sig; - for (sig = 1; sig < NSIG; sig++) { - if (G.traps[sig] && !G.traps[sig][0]) - empty_trap_mask |= 1LL << sig; +#if HAS_KEYWORDS +# if ENABLE_HUSH_CASE + if (ctx->ctx_dsemicolon + && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */ + ) { + /* already done when ctx_dsemicolon was set to 1: */ + /* ctx->ctx_res_w = RES_MATCH; */ + ctx->ctx_dsemicolon = 0; + } else +# endif + if (!command->argv /* if it's the first word... */ +# if ENABLE_HUSH_LOOPS + && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */ + && ctx->ctx_res_w != RES_IN +# endif +# if ENABLE_HUSH_CASE + && ctx->ctx_res_w != RES_CASE +# endif + ) { + debug_printf_parse("checking '%s' for reserved-ness\n", word->data); + if (reserved_word(word, ctx)) { + o_reset_to_empty_unquoted(word); + debug_printf_parse("done_word return %d\n", + (ctx->ctx_res_w == RES_SNTX)); + return (ctx->ctx_res_w == RES_SNTX); + } +# ifdef CMD_SINGLEWORD_NOGLOB_COND + if (strcmp(word->data, "export") == 0 +# if ENABLE_HUSH_LOCAL + || strcmp(word->data, "local") == 0 +# endif + ) { + command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND; + } else +# endif +# if ENABLE_HUSH_BASH_COMPAT + if (strcmp(word->data, "[[") == 0) { + command->cmd_type = CMD_SINGLEWORD_NOGLOB; + } + /* fall through */ +# endif + } +#endif + if (command->group) { + /* "{ echo foo; } echo bar" - bad */ + syntax_error_at(word->data); + debug_printf_parse("done_word return 1: syntax error, " + "groups and arglists don't mix\n"); + return 1; } + if (word->has_quoted_part + /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ + && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) + /* (otherwise it's known to be not empty and is already safe) */ + ) { + /* exclude "$@" - it can expand to no word despite "" */ + char *p = word->data; + while (p[0] == SPECIAL_VAR_SYMBOL + && (p[1] & 0x7f) == '@' + && p[2] == SPECIAL_VAR_SYMBOL + ) { + p += 3; + } + if (p == word->data || p[0] != '\0') { + /* saw no "$@", or not only "$@" but some + * real text is there too */ + /* insert "empty variable" reference, this makes + * e.g. "", $empty"" etc to not disappear */ + o_addchr(word, SPECIAL_VAR_SYMBOL); + o_addchr(word, SPECIAL_VAR_SYMBOL); + } + } + command->argv = add_string_to_strings(command->argv, xstrdup(word->data)); + debug_print_strings("word appended to argv", command->argv); } - sprintf(param_buf, NOMMU_HACK_FMT - , (unsigned) G.root_pid - , (unsigned) G.root_ppid - , (unsigned) G.last_bg_pid - , (unsigned) G.last_exitcode - , cnt - , empty_trap_mask - IF_HUSH_LOOPS(, G.depth_of_loop) - ); -# undef NOMMU_HACK_FMT - /* 1:hush 2:-$::: - * 3:-c 4: 5: 6:NULL - */ - cnt += 6; - for (cur = G.top_var; cur; cur = cur->next) { - if (!cur->flg_export || cur->flg_read_only) - cnt += 2; - } -# if ENABLE_HUSH_FUNCTIONS - for (funcp = G.top_func; funcp; funcp = funcp->next) - cnt += 3; -# endif - pp = g_argv; - while (*pp++) - cnt++; - *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt); - *pp++ = (char *) G.argv0_for_re_execing; - *pp++ = param_buf; - for (cur = G.top_var; cur; cur = cur->next) { - if (strcmp(cur->varstr, hush_version_str) == 0) - continue; - if (cur->flg_read_only) { - *pp++ = (char *) "-R"; - *pp++ = cur->varstr; - } else if (!cur->flg_export) { - *pp++ = (char *) "-V"; - *pp++ = cur->varstr; +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR) { + if (word->has_quoted_part + || !is_well_formed_var_name(command->argv[0], '\0') + ) { + /* bash says just "not a valid identifier" */ + syntax_error("not a valid identifier in for"); + return 1; } + /* Force FOR to have just one word (variable name) */ + /* NB: basically, this makes hush see "for v in ..." + * syntax as if it is "for v; in ...". FOR and IN become + * two pipe structs in parse tree. */ + done_pipe(ctx, PIPE_SEQ); } -# if ENABLE_HUSH_FUNCTIONS - for (funcp = G.top_func; funcp; funcp = funcp->next) { - *pp++ = (char *) "-F"; - *pp++ = funcp->name; - *pp++ = funcp->body_as_string; - } -# endif - /* We can pass activated traps here. Say, -Tnn:trap_string - * - * However, POSIX says that subshells reset signals with traps - * to SIG_DFL. - * I tested bash-3.2 and it not only does that with true subshells - * of the form ( list ), but with any forked children shells. - * I set trap "echo W" WINCH; and then tried: - * - * { echo 1; sleep 20; echo 2; } & - * while true; do echo 1; sleep 20; echo 2; break; done & - * true | { echo 1; sleep 20; echo 2; } | cat - * - * In all these cases sending SIGWINCH to the child shell - * did not run the trap. If I add trap "echo V" WINCH; - * _inside_ group (just before echo 1), it works. - * - * I conclude it means we don't need to pass active traps here. - * Even if we would use signal handlers instead of signal masking - * in order to implement trap handling, - * exec syscall below resets signals to SIG_DFL for us. - */ - *pp++ = (char *) "-c"; - *pp++ = (char *) s; - if (builtin_argv) { - while (*++builtin_argv) - *pp++ = *builtin_argv; - *pp++ = (char *) ""; +#endif +#if ENABLE_HUSH_CASE + /* Force CASE to have just one word */ + if (ctx->ctx_res_w == RES_CASE) { + done_pipe(ctx, PIPE_SEQ); } - *pp++ = g_argv0; - while (*g_argv) - *pp++ = *g_argv++; - /* *pp = NULL; - is already there */ - pp = environ; +#endif - do_exec: - debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s); - sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); - execve(bb_busybox_exec_path, argv, pp); - /* Fallback. Useful for init=/bin/hush usage etc */ - if (argv[0][0] == '/') - execve(argv[0], argv, pp); - xfunc_error_retval = 127; - bb_error_msg_and_die("can't re-execute the shell"); + o_reset_to_empty_unquoted(word); + + debug_printf_parse("done_word return 0\n"); + return 0; } -#endif /* !BB_MMU */ -static void setup_heredoc(struct redir_struct *redir) -{ - struct fd_pair pair; - pid_t pid; - int len, written; - /* the _body_ of heredoc (misleading field name) */ - const char *heredoc = redir->rd_filename; - char *expanded; -#if !BB_MMU - char **to_free; +/* Peek ahead in the input to find out if we have a "&n" construct, + * as in "2>&1", that represents duplicating a file descriptor. + * Return: + * REDIRFD_CLOSE if >&- "close fd" construct is seen, + * REDIRFD_SYNTAX_ERR if syntax error, + * REDIRFD_TO_FILE if no & was seen, + * or the number found. + */ +#if BB_MMU +#define parse_redir_right_fd(as_string, input) \ + parse_redir_right_fd(input) #endif +static int parse_redir_right_fd(o_string *as_string, struct in_str *input) +{ + int ch, d, ok; - expanded = NULL; - if (!(redir->rd_dup & HEREDOC_QUOTED)) { - expanded = expand_pseudo_dquoted(heredoc); - if (expanded) - heredoc = expanded; + ch = i_peek(input); + if (ch != '&') + return REDIRFD_TO_FILE; + + ch = i_getch(input); /* get the & */ + nommu_addchr(as_string, ch); + ch = i_peek(input); + if (ch == '-') { + ch = i_getch(input); + nommu_addchr(as_string, ch); + return REDIRFD_CLOSE; } - len = strlen(heredoc); + d = 0; + ok = 0; + while (ch != EOF && isdigit(ch)) { + d = d*10 + (ch-'0'); + ok = 1; + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek(input); + } + if (ok) return d; - close(redir->rd_fd); /* often saves dup2+close in xmove_fd */ - xpiped_pair(pair); - xmove_fd(pair.rd, redir->rd_fd); +//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2) - /* Try writing without forking. Newer kernels have - * dynamically growing pipes. Must use non-blocking write! */ - ndelay_on(pair.wr); - while (1) { - written = write(pair.wr, heredoc, len); - if (written <= 0) - break; - len -= written; - if (len == 0) { - close(pair.wr); - free(expanded); - return; + bb_error_msg("ambiguous redirect"); + return REDIRFD_SYNTAX_ERR; +} + +/* Return code is 0 normal, 1 if a syntax error is detected + */ +static int parse_redirect(struct parse_context *ctx, + int fd, + redir_type style, + struct in_str *input) +{ + struct command *command = ctx->command; + struct redir_struct *redir; + struct redir_struct **redirp; + int dup_num; + + dup_num = REDIRFD_TO_FILE; + if (style != REDIRECT_HEREDOC) { + /* Check for a '>&1' type redirect */ + dup_num = parse_redir_right_fd(&ctx->as_string, input); + if (dup_num == REDIRFD_SYNTAX_ERR) + return 1; + } else { + int ch = i_peek(input); + dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */ + if (dup_num) { /* <<-... */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + ch = i_peek(input); } - heredoc += written; } - ndelay_off(pair.wr); - /* Okay, pipe buffer was not big enough */ - /* Note: we must not create a stray child (bastard? :) - * for the unsuspecting parent process. Child creates a grandchild - * and exits before parent execs the process which consumes heredoc - * (that exec happens after we return from this function) */ -#if !BB_MMU - to_free = NULL; -#endif - pid = xvfork(); - if (pid == 0) { - /* child */ - disable_restore_tty_pgrp_on_exit(); - pid = BB_MMU ? xfork() : xvfork(); - if (pid != 0) - _exit(0); - /* grandchild */ - close(redir->rd_fd); /* read side of the pipe */ + if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) { + int ch = i_peek(input); + if (ch == '|') { + /* >|FILE redirect ("clobbering" >). + * Since we do not support "set -o noclobber" yet, + * >| and > are the same for now. Just eat |. + */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + } + } + + /* Create a new redir_struct and append it to the linked list */ + redirp = &command->redirects; + while ((redir = *redirp) != NULL) { + redirp = &(redir->next); + } + *redirp = redir = xzalloc(sizeof(*redir)); + /* redir->next = NULL; */ + /* redir->rd_filename = NULL; */ + redir->rd_type = style; + redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd; + + debug_printf_parse("redirect type %d %s\n", redir->rd_fd, + redir_table[style].descrip); + + redir->rd_dup = dup_num; + if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) { + /* Erik had a check here that the file descriptor in question + * is legit; I postpone that to "run time" + * A "-" representation of "close me" shows up as a -3 here */ + debug_printf_parse("duplicating redirect '%d>&%d'\n", + redir->rd_fd, redir->rd_dup); + } else { + /* Set ctx->pending_redirect, so we know what to do at the + * end of the next parsed word. */ + ctx->pending_redirect = redir; + } + return 0; +} + +/* If a redirect is immediately preceded by a number, that number is + * supposed to tell which file descriptor to redirect. This routine + * looks for such preceding numbers. In an ideal world this routine + * needs to handle all the following classes of redirects... + * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo + * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo + * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo + * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo + * + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html + * "2.7 Redirection + * ... If n is quoted, the number shall not be recognized as part of + * the redirection expression. For example: + * echo \2>a + * writes the character 2 into file a" + * We are getting it right by setting ->has_quoted_part on any \ + * + * A -1 return means no valid number was found, + * the caller should use the appropriate default for this redirection. + */ +static int redirect_opt_num(o_string *o) +{ + int num; + + if (o->data == NULL) + return -1; + num = bb_strtou(o->data, NULL, 10); + if (errno || num < 0) + return -1; + o_reset_to_empty_unquoted(o); + return num; +} + #if BB_MMU - full_write(pair.wr, heredoc, len); /* may loop or block */ - _exit(0); -#else - /* Delegate blocking writes to another process */ - xmove_fd(pair.wr, STDOUT_FILENO); - re_execute_shell(&to_free, heredoc, NULL, NULL, NULL); +#define fetch_till_str(as_string, input, word, skip_tabs) \ + fetch_till_str(input, word, skip_tabs) #endif +static char *fetch_till_str(o_string *as_string, + struct in_str *input, + const char *word, + int skip_tabs) +{ + o_string heredoc = NULL_O_STRING; + int past_EOL = 0; + int ch; + + goto jump_in; + while (1) { + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == '\n') { + if (strcmp(heredoc.data + past_EOL, word) == 0) { + heredoc.data[past_EOL] = '\0'; + debug_printf_parse("parsed heredoc '%s'\n", heredoc.data); + return heredoc.data; + } + do { + o_addchr(&heredoc, ch); + past_EOL = heredoc.length; + jump_in: + do { + ch = i_getch(input); + nommu_addchr(as_string, ch); + } while (skip_tabs && ch == '\t'); + } while (ch == '\n'); + } + if (ch == EOF) { + o_free_unsafe(&heredoc); + return NULL; + } + o_addchr(&heredoc, ch); + nommu_addchr(as_string, ch); } - /* parent */ -#if ENABLE_HUSH_FAST - G.count_SIGCHLD++; -//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); -#endif - enable_restore_tty_pgrp_on_exit(); -#if !BB_MMU - free(to_free); -#endif - close(pair.wr); - free(expanded); - wait(NULL); /* wait till child has died */ } -/* squirrel != NULL means we squirrel away copies of stdin, stdout, - * and stderr if they are redirected. */ -static int setup_redirects(struct command *prog, int squirrel[]) +/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs + * and load them all. There should be exactly heredoc_cnt of them. + */ +static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input) { - int openfd, mode; - struct redir_struct *redir; + struct pipe *pi = ctx->list_head; - for (redir = prog->redirects; redir; redir = redir->next) { - if (redir->rd_type == REDIRECT_HEREDOC2) { - /* rd_fd<rd_fd < 3 - && squirrel[redir->rd_fd] < 0 - ) { - squirrel[redir->rd_fd] = dup(redir->rd_fd); - } - /* for REDIRECT_HEREDOC2, rd_filename holds _contents_ - * of the heredoc */ - debug_printf_parse("set heredoc '%s'\n", - redir->rd_filename); - setup_heredoc(redir); - continue; - } + while (pi && heredoc_cnt) { + int i; + struct command *cmd = pi->cmds; - if (redir->rd_dup == REDIRFD_TO_FILE) { - /* rd_fd<*>file case (<*> is <,>,>>,<>) */ - char *p; - if (redir->rd_filename == NULL) { - /* Something went wrong in the parse. - * Pretend it didn't happen */ - bb_error_msg("bug in redirect parse"); - continue; - } - mode = redir_table[redir->rd_type].mode; - p = expand_string_to_string(redir->rd_filename); - openfd = open_or_warn(p, mode); - free(p); - if (openfd < 0) { - /* this could get lost if stderr has been redirected, but - * bash and ash both lose it as well (though zsh doesn't!) */ -//what the above comment tries to say? - return 1; - } - } else { - /* rd_fd<*>rd_dup or rd_fd<*>- cases */ - openfd = redir->rd_dup; - } + debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n", + pi->num_cmds, + cmd->argv ? cmd->argv[0] : "NONE"); + for (i = 0; i < pi->num_cmds; i++) { + struct redir_struct *redir = cmd->redirects; - if (openfd != redir->rd_fd) { - if (squirrel && redir->rd_fd < 3 - && squirrel[redir->rd_fd] < 0 - ) { - squirrel[redir->rd_fd] = dup(redir->rd_fd); - } - if (openfd == REDIRFD_CLOSE) { - /* "n>-" means "close me" */ - close(redir->rd_fd); - } else { - xdup2(openfd, redir->rd_fd); - if (redir->rd_dup == REDIRFD_TO_FILE) - close(openfd); + debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n", + i, cmd->argv ? cmd->argv[0] : "NONE"); + while (redir) { + if (redir->rd_type == REDIRECT_HEREDOC) { + char *p; + + redir->rd_type = REDIRECT_HEREDOC2; + /* redir->rd_dup is (ab)used to indicate <<- */ + p = fetch_till_str(&ctx->as_string, input, + redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS); + if (!p) { + syntax_error("unexpected EOF in here document"); + return 1; + } + free(redir->rd_filename); + redir->rd_filename = p; + heredoc_cnt--; + } + redir = redir->next; } + cmd++; } + pi = pi->next; } +#if 0 + /* Should be 0. If it isn't, it's a parse error */ + if (heredoc_cnt) + bb_error_msg_and_die("heredoc BUG 2"); +#endif return 0; } -static void restore_redirects(int squirrel[]) -{ - int i, fd; - for (i = 0; i < 3; i++) { - fd = squirrel[i]; - if (fd != -1) { - /* We simply die on error */ - xmove_fd(fd, i); - } - } -} +static int run_list(struct pipe *pi); +#if BB_MMU +#define parse_stream(pstring, input, end_trigger) \ + parse_stream(input, end_trigger) +#endif +static struct pipe *parse_stream(char **pstring, + struct in_str *input, + int end_trigger); -static void free_pipe_list(struct pipe *head); -/* Return code is the exit status of the pipe */ -static void free_pipe(struct pipe *pi) +#if !ENABLE_HUSH_FUNCTIONS +#define parse_group(dest, ctx, input, ch) \ + parse_group(ctx, input, ch) +#endif +static int parse_group(o_string *dest, struct parse_context *ctx, + struct in_str *input, int ch) { - char **p; - struct command *command; - struct redir_struct *r, *rnext; - int a, i; + /* dest contains characters seen prior to ( or {. + * Typically it's empty, but for function defs, + * it contains function name (without '()'). */ + struct pipe *pipe_list; + int endch; + struct command *command = ctx->command; - if (pi->stopped_cmds > 0) /* why? */ - return; - debug_printf_clean("run pipe: (pid %d)\n", getpid()); - for (i = 0; i < pi->num_cmds; i++) { - command = &pi->cmds[i]; - debug_printf_clean(" command %d:\n", i); - if (command->argv) { - for (a = 0, p = command->argv; *p; a++, p++) { - debug_printf_clean(" argv[%d] = %s\n", a, *p); - } - free_strings(command->argv); - command->argv = NULL; - } - /* not "else if": on syntax error, we may have both! */ - if (command->group) { - debug_printf_clean(" begin group (cmd_type:%d)\n", - command->cmd_type); - free_pipe_list(command->group); - debug_printf_clean(" end group\n"); - command->group = NULL; - } - /* else is crucial here. - * If group != NULL, child_func is meaningless */ + debug_printf_parse("parse_group entered\n"); #if ENABLE_HUSH_FUNCTIONS - else if (command->child_func) { - debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func); - command->child_func->parent_cmd = NULL; + if (ch == '(' && !dest->has_quoted_part) { + if (dest->length) + if (done_word(dest, ctx)) + return 1; + if (!command->argv) + goto skip; /* (... */ + if (command->argv[1]) { /* word word ... (... */ + syntax_error_unexpected_ch('('); + return 1; } -#endif -#if !BB_MMU - free(command->group_as_string); - command->group_as_string = NULL; -#endif - for (r = command->redirects; r; r = rnext) { - debug_printf_clean(" redirect %d%s", - r->rd_fd, redir_table[r->rd_type].descrip); - /* guard against the case >$FOO, where foo is unset or blank */ - if (r->rd_filename) { - debug_printf_clean(" fname:'%s'\n", r->rd_filename); - free(r->rd_filename); - r->rd_filename = NULL; - } - debug_printf_clean(" rd_dup:%d\n", r->rd_dup); - rnext = r->next; - free(r); + /* it is "word(..." or "word (..." */ + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t'); + if (ch != ')') { + syntax_error_unexpected_ch(ch); + return 1; + } + nommu_addchr(&ctx->as_string, ch); + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t' || ch == '\n'); + if (ch != '{') { + syntax_error_unexpected_ch(ch); + return 1; } - command->redirects = NULL; + nommu_addchr(&ctx->as_string, ch); + command->cmd_type = CMD_FUNCDEF; + goto skip; } - free(pi->cmds); /* children are an array, they get freed all at once */ - pi->cmds = NULL; -#if ENABLE_HUSH_JOB - free(pi->cmdtext); - pi->cmdtext = NULL; #endif -} -static void free_pipe_list(struct pipe *head) -{ - struct pipe *pi, *next; +#if 0 /* Prevented by caller */ + if (command->argv /* word [word]{... */ + || dest->length /* word{... */ + || dest->has_quoted_part /* ""{... */ + ) { + syntax_error(NULL); + debug_printf_parse("parse_group return 1: " + "syntax error, groups and arglists don't mix\n"); + return 1; + } +#endif - for (pi = head; pi; pi = next) { -#if HAS_KEYWORDS - debug_printf_clean(" pipe reserved word %d\n", pi->res_word); +#if ENABLE_HUSH_FUNCTIONS + skip: #endif - free_pipe(pi); - debug_printf_clean("pipe followup code %d\n", pi->followup); - next = pi->next; - /*pi->next = NULL;*/ - free(pi); + endch = '}'; + if (ch == '(') { + endch = ')'; + command->cmd_type = CMD_SUBSHELL; + } else { + /* bash does not allow "{echo...", requires whitespace */ + ch = i_getch(input); + if (ch != ' ' && ch != '\t' && ch != '\n') { + syntax_error_unexpected_ch(ch); + return 1; + } + nommu_addchr(&ctx->as_string, ch); } -} - -static int run_list(struct pipe *pi); + { #if BB_MMU -#define parse_stream(pstring, input, end_trigger) \ - parse_stream(input, end_trigger) +# define as_string NULL +#else + char *as_string = NULL; #endif -static struct pipe *parse_stream(char **pstring, - struct in_str *input, - int end_trigger); -static void parse_and_run_string(const char *s); - - -static char *find_in_path(const char *arg) -{ - char *ret = NULL; - const char *PATH = get_local_var_value("PATH"); - - if (!PATH) - return NULL; - - while (1) { - const char *end = strchrnul(PATH, ':'); - int sz = end - PATH; /* must be int! */ - - free(ret); - if (sz != 0) { - ret = xasprintf("%.*s/%s", sz, PATH, arg); - } else { - /* We have xxx::yyyy in $PATH, - * it means "use current dir" */ - ret = xstrdup(arg); - } - if (access(ret, F_OK) == 0) - break; - - if (*end == '\0') { - free(ret); - return NULL; + pipe_list = parse_stream(&as_string, input, endch); +#if !BB_MMU + if (as_string) + o_addstr(&ctx->as_string, as_string); +#endif + /* empty ()/{} or parse error? */ + if (!pipe_list || pipe_list == ERR_PTR) { + /* parse_stream already emitted error msg */ + if (!BB_MMU) + free(as_string); + debug_printf_parse("parse_group return 1: " + "parse_stream returned %p\n", pipe_list); + return 1; } - PATH = end + 1; + command->group = pipe_list; +#if !BB_MMU + as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */ + command->group_as_string = as_string; + debug_printf_parse("end of group, remembering as:'%s'\n", + command->group_as_string); +#endif +#undef as_string } - - return ret; + debug_printf_parse("parse_group return 0\n"); + return 0; + /* command remains "open", available for possible redirects */ } -static const struct built_in_command* find_builtin_helper(const char *name, - const struct built_in_command *x, - const struct built_in_command *end) +#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS +/* Subroutines for copying $(...) and `...` things */ +static void add_till_backquote(o_string *dest, struct in_str *input); +/* '...' */ +static void add_till_single_quote(o_string *dest, struct in_str *input) { - while (x != end) { - if (strcmp(name, x->b_cmd) != 0) { - x++; - continue; + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('\''); + /*xfunc_die(); - redundant */ } - debug_printf_exec("found builtin '%s'\n", name); - return x; + if (ch == '\'') + return; + o_addchr(dest, ch); } - return NULL; -} -static const struct built_in_command* find_builtin1(const char *name) -{ - return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]); -} -static const struct built_in_command* find_builtin(const char *name) -{ - const struct built_in_command *x = find_builtin1(name); - if (x) - return x; - return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]); } - -#if ENABLE_HUSH_FUNCTIONS -static struct function **find_function_slot(const char *name) +/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */ +static void add_till_double_quote(o_string *dest, struct in_str *input) { - struct function **funcpp = &G.top_func; - while (*funcpp) { - if (strcmp(name, (*funcpp)->name) == 0) { - break; + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('"'); + /*xfunc_die(); - redundant */ } - funcpp = &(*funcpp)->next; - } - return funcpp; -} - -static const struct function *find_function(const char *name) -{ - const struct function *funcp = *find_function_slot(name); - if (funcp) - debug_printf_exec("found function '%s'\n", name); - return funcp; -} - -/* Note: takes ownership on name ptr */ -static struct function *new_function(char *name) -{ - struct function **funcpp = find_function_slot(name); - struct function *funcp = *funcpp; - - if (funcp != NULL) { - struct command *cmd = funcp->parent_cmd; - debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd); - if (!cmd) { - debug_printf_exec("freeing & replacing function '%s'\n", funcp->name); - free(funcp->name); - /* Note: if !funcp->body, do not free body_as_string! - * This is a special case of "-F name body" function: - * body_as_string was not malloced! */ - if (funcp->body) { - free_pipe_list(funcp->body); -# if !BB_MMU - free(funcp->body_as_string); -# endif - } - } else { - debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name); - cmd->argv[0] = funcp->name; - cmd->group = funcp->body; -# if !BB_MMU - cmd->group_as_string = funcp->body_as_string; -# endif + if (ch == '"') + return; + if (ch == '\\') { /* \x. Copy both chars. */ + o_addchr(dest, ch); + ch = i_getch(input); } - } else { - debug_printf_exec("remembering new function '%s'\n", name); - funcp = *funcpp = xzalloc(sizeof(*funcp)); - /*funcp->next = NULL;*/ + o_addchr(dest, ch); + if (ch == '`') { + add_till_backquote(dest, input); + o_addchr(dest, ch); + continue; + } + //if (ch == '$') ... } - - funcp->name = name; - return funcp; } - -static void unset_func(const char *name) -{ - struct function **funcpp = find_function_slot(name); - struct function *funcp = *funcpp; - - if (funcp != NULL) { - debug_printf_exec("freeing function '%s'\n", funcp->name); - *funcpp = funcp->next; - /* funcp is unlinked now, deleting it. - * Note: if !funcp->body, the function was created by - * "-F name body", do not free ->body_as_string - * and ->name as they were not malloced. */ - if (funcp->body) { - free_pipe_list(funcp->body); - free(funcp->name); -# if !BB_MMU - free(funcp->body_as_string); -# endif +/* Process `cmd` - copy contents until "`" is seen. Complicated by + * \` quoting. + * "Within the backquoted style of command substitution, backslash + * shall retain its literal meaning, except when followed by: '$', '`', or '\'. + * The search for the matching backquote shall be satisfied by the first + * backquote found without a preceding backslash; during this search, + * if a non-escaped backquote is encountered within a shell comment, + * a here-document, an embedded command substitution of the $(command) + * form, or a quoted string, undefined results occur. A single-quoted + * or double-quoted string that begins, but does not end, within the + * "`...`" sequence produces undefined results." + * Example Output + * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST + */ +static void add_till_backquote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('`'); + /*xfunc_die(); - redundant */ } - free(funcp); + if (ch == '`') + return; + if (ch == '\\') { + /* \x. Copy both chars unless it is \` */ + int ch2 = i_getch(input); + if (ch2 == EOF) { + syntax_error_unterm_ch('`'); + /*xfunc_die(); - redundant */ + } + if (ch2 != '`' && ch2 != '$' && ch2 != '\\') + o_addchr(dest, ch); + ch = ch2; + } + o_addchr(dest, ch); } } - -# if BB_MMU -#define exec_function(to_free, funcp, argv) \ - exec_function(funcp, argv) -# endif -static void exec_function(char ***to_free, - const struct function *funcp, - char **argv) NORETURN; -static void exec_function(char ***to_free, - const struct function *funcp, - char **argv) -{ -# if BB_MMU - int n = 1; - - argv[0] = G.global_argv[0]; - G.global_argv = argv; - while (*++argv) - n++; - G.global_argc = n; - /* On MMU, funcp->body is always non-NULL */ - n = run_list(funcp->body); - fflush_all(); - _exit(n); -# else - re_execute_shell(to_free, - funcp->body_as_string, - G.global_argv[0], - argv + 1, - NULL); -# endif -} - -static int run_function(const struct function *funcp, char **argv) +/* Process $(cmd) - copy contents until ")" is seen. Complicated by + * quoting and nested ()s. + * "With the $(command) style of command substitution, all characters + * following the open parenthesis to the matching closing parenthesis + * constitute the command. Any valid shell script can be used for command, + * except a script consisting solely of redirections which produces + * unspecified results." + * Example Output + * echo $(echo '(TEST)' BEST) (TEST) BEST + * echo $(echo 'TEST)' BEST) TEST) BEST + * echo $(echo \(\(TEST\) BEST) ((TEST) BEST + * + * Also adapted to eat ${var%...} and $((...)) constructs, since ... part + * can contain arbitrary constructs, just like $(cmd). + * In bash compat mode, it needs to also be able to stop on ':' or '/' + * for ${var:N[:M]} and ${var/P[/R]} parsing. + */ +#define DOUBLE_CLOSE_CHAR_FLAG 0x80 +static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch) { - int rc; - save_arg_t sv; - smallint sv_flg; - - save_and_replace_G_args(&sv, argv); - - /* "we are in function, ok to use return" */ - sv_flg = G.flag_return_in_progress; - G.flag_return_in_progress = -1; -# if ENABLE_HUSH_LOCAL - G.func_nest_level++; -# endif - - /* On MMU, funcp->body is always non-NULL */ -# if !BB_MMU - if (!funcp->body) { - /* Function defined by -F */ - parse_and_run_string(funcp->body_as_string); - rc = G.last_exitcode; - } else + int ch; + char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG; +# if ENABLE_HUSH_BASH_COMPAT + char end_char2 = end_ch >> 8; # endif - { - rc = run_list(funcp->body); - } - -# if ENABLE_HUSH_LOCAL - { - struct variable *var; - struct variable **var_pp; + end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1); - var_pp = &G.top_var; - while ((var = *var_pp) != NULL) { - if (var->func_nest_level < G.func_nest_level) { - var_pp = &var->next; - continue; + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(end_ch); + /*xfunc_die(); - redundant */ + } + if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) { + if (!dbl) + break; + /* we look for closing )) of $((EXPR)) */ + if (i_peek(input) == end_ch) { + i_getch(input); /* eat second ')' */ + break; } - /* Unexport */ - if (var->flg_export) - bb_unsetenv(var->varstr); - /* Remove from global list */ - *var_pp = var->next; - /* Free */ - if (!var->max_len) - free(var->varstr); - free(var); } - G.func_nest_level--; + o_addchr(dest, ch); + if (ch == '(' || ch == '{') { + ch = (ch == '(' ? ')' : '}'); + add_till_closing_bracket(dest, input, ch); + o_addchr(dest, ch); + continue; + } + if (ch == '\'') { + add_till_single_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '"') { + add_till_double_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '`') { + add_till_backquote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '\\') { + /* \x. Copy verbatim. Important for \(, \) */ + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(')'); + /*xfunc_die(); - redundant */ + } + o_addchr(dest, ch); + continue; + } } -# endif - G.flag_return_in_progress = sv_flg; - - restore_G_args(&sv, argv); - - return rc; + return ch; } -#endif /* ENABLE_HUSH_FUNCTIONS */ - +#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */ +/* Return code: 0 for OK, 1 for syntax error */ #if BB_MMU -#define exec_builtin(to_free, x, argv) \ - exec_builtin(x, argv) -#else -#define exec_builtin(to_free, x, argv) \ - exec_builtin(to_free, argv) -#endif -static void exec_builtin(char ***to_free, - const struct built_in_command *x, - char **argv) NORETURN; -static void exec_builtin(char ***to_free, - const struct built_in_command *x, - char **argv) -{ -#if BB_MMU - int rcode = x->b_function(argv); - fflush_all(); - _exit(rcode); -#else - /* On NOMMU, we must never block! - * Example: { sleep 99 | read line; } & echo Ok - */ - re_execute_shell(to_free, - argv[0], - G.global_argv[0], - G.global_argv + 1, - argv); +#define parse_dollar(as_string, dest, input) \ + parse_dollar(dest, input) +#define as_string NULL #endif -} - - -static void execvp_or_die(char **argv) NORETURN; -static void execvp_or_die(char **argv) +static int parse_dollar(o_string *as_string, + o_string *dest, + struct in_str *input) { - debug_printf_exec("execing '%s'\n", argv[0]); - sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); - execvp(argv[0], argv); - bb_perror_msg("can't execute '%s'", argv[0]); - _exit(127); /* bash compat */ -} + int ch = i_peek(input); /* first character after the $ */ + unsigned char quote_mask = dest->o_escape ? 0x80 : 0; -#if ENABLE_HUSH_MODE_X -static void dump_cmd_in_x_mode(char **argv) -{ - if (G_x_mode && argv) { - /* We want to output the line in one write op */ - char *buf, *p; - int len; - int n; + debug_printf_parse("parse_dollar entered: ch='%c'\n", ch); + if (isalpha(ch)) { + ch = i_getch(input); + nommu_addchr(as_string, ch); + make_var: + o_addchr(dest, SPECIAL_VAR_SYMBOL); + while (1) { + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + ch = i_peek(input); + if (!isalnum(ch) && ch != '_') + break; + ch = i_getch(input); + nommu_addchr(as_string, ch); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else if (isdigit(ch)) { + make_one_char_var: + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else switch (ch) { + case '$': /* pid */ + case '!': /* last bg pid */ + case '?': /* last exit code */ + case '#': /* number of args */ + case '*': /* args */ + case '@': /* args */ + goto make_one_char_var; + case '{': { + o_addchr(dest, SPECIAL_VAR_SYMBOL); - len = 3; - n = 0; - while (argv[n]) - len += strlen(argv[n++]) + 1; - buf = xmalloc(len); - buf[0] = '+'; - p = buf + 1; - n = 0; - while (argv[n]) - p += sprintf(p, " %s", argv[n++]); - *p++ = '\n'; - *p = '\0'; - fputs(buf, stderr); - free(buf); - } -} -#else -# define dump_cmd_in_x_mode(argv) ((void)0) -#endif + ch = i_getch(input); /* eat '{' */ + nommu_addchr(as_string, ch); -#if BB_MMU -#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \ - pseudo_exec_argv(argv, assignment_cnt, argv_expanded) -#define pseudo_exec(nommu_save, command, argv_expanded) \ - pseudo_exec(command, argv_expanded) -#endif + ch = i_getch(input); /* first char after '{' */ + nommu_addchr(as_string, ch); + /* It should be ${?}, or ${#var}, + * or even ${?+subst} - operator acting on a special variable, + * or the beginning of variable name. + */ + if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */ + bad_dollar_syntax: + syntax_error_unterm_str("${name}"); + debug_printf_parse("parse_dollar return 1: unterminated ${name}\n"); + return 1; + } + ch |= quote_mask; -/* Called after [v]fork() in run_pipe, or from builtin_exec. - * Never returns. - * Don't exit() here. If you don't exec, use _exit instead. - * The at_exit handlers apparently confuse the calling process, - * in particular stdin handling. Not sure why? -- because of vfork! (vda) */ -static void pseudo_exec_argv(nommu_save_t *nommu_save, - char **argv, int assignment_cnt, - char **argv_expanded) NORETURN; -static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save, - char **argv, int assignment_cnt, - char **argv_expanded) -{ - char **new_env; + /* It's possible to just call add_till_closing_bracket() at this point. + * However, this regresses some of our testsuite cases + * which check invalid constructs like ${%}. + * Oh well... let's check that the var name part is fine... */ - new_env = expand_assignments(argv, assignment_cnt); - dump_cmd_in_x_mode(new_env); + while (1) { + unsigned pos; - if (!argv[assignment_cnt]) { - /* Case when we are here: ... | var=val | ... - * (note that we do not exit early, i.e., do not optimize out - * expand_assignments(): think about ... | var=`sleep 1` | ... - */ - free_strings(new_env); - _exit(EXIT_SUCCESS); - } + o_addchr(dest, ch); + debug_printf_parse(": '%c'\n", ch); -#if BB_MMU - set_vars_and_save_old(new_env); - free(new_env); /* optional */ - /* we can also destroy set_vars_and_save_old's return value, - * to save memory */ -#else - nommu_save->new_env = new_env; - nommu_save->old_vars = set_vars_and_save_old(new_env); -#endif + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == '}') + break; - if (argv_expanded) { - argv = argv_expanded; - } else { - argv = expand_strvec_to_strvec(argv + assignment_cnt); -#if !BB_MMU - nommu_save->argv = argv; -#endif - } - dump_cmd_in_x_mode(argv); + if (!isalnum(ch) && ch != '_') { + unsigned end_ch; + unsigned char last_ch; + /* handle parameter expansions + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02 + */ + if (!strchr(VAR_SUBST_OPS, ch)) /* ${var... */ + goto bad_dollar_syntax; -#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU - if (strchr(argv[0], '/') != NULL) - goto skip; + /* Eat everything until closing '}' (or ':') */ + end_ch = '}'; + if (ENABLE_HUSH_BASH_COMPAT + && ch == ':' + && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input)) + ) { + /* It's ${var:N[:M]} thing */ + end_ch = '}' * 0x100 + ':'; + } + if (ENABLE_HUSH_BASH_COMPAT + && ch == '/' + ) { + /* It's ${var/[/]pattern[/repl]} thing */ + if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */ + i_getch(input); + nommu_addchr(as_string, '/'); + ch = '\\'; + } + end_ch = '}' * 0x100 + '/'; + } + o_addchr(dest, ch); + again: + if (!BB_MMU) + pos = dest->length; +#if ENABLE_HUSH_DOLLAR_OPS + last_ch = add_till_closing_bracket(dest, input, end_ch); +#else +#error Simple code to only allow ${var} is not implemented #endif + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, last_ch); + } - /* Check if the command matches any of the builtins. - * Depending on context, this might be redundant. But it's - * easier to waste a few CPU cycles than it is to figure out - * if this is one of those cases. - */ - { - /* On NOMMU, it is more expensive to re-execute shell - * just in order to run echo or test builtin. - * It's better to skip it here and run corresponding - * non-builtin later. */ - const struct built_in_command *x; - x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]); - if (x) { - exec_builtin(&nommu_save->argv_from_re_execing, x, argv); - } - } -#if ENABLE_HUSH_FUNCTIONS - /* Check if the command matches any functions */ - { - const struct function *funcp = find_function(argv[0]); - if (funcp) { - exec_function(&nommu_save->argv_from_re_execing, funcp, argv); + if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) { + /* close the first block: */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + /* while parsing N from ${var:N[:M]} + * or pattern from ${var/[/]pattern[/repl]} */ + if ((end_ch & 0xff) == last_ch) { + /* got ':' or '/'- parse the rest */ + end_ch = '}'; + goto again; + } + /* got '}' */ + if (end_ch == '}' * 0x100 + ':') { + /* it's ${var:N} - emulate :999999999 */ + o_addstr(dest, "999999999"); + } /* else: it's ${var/[/]pattern} */ + } + break; + } } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; } -#endif +#if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK + case '(': { + unsigned pos; -#if ENABLE_FEATURE_SH_STANDALONE - /* Check if the command matches any busybox applets */ - { - int a = find_applet_by_name(argv[0]); - if (a >= 0) { -# if BB_MMU /* see above why on NOMMU it is not allowed */ - if (APPLET_IS_NOEXEC(a)) { - debug_printf_exec("running applet '%s'\n", argv[0]); - run_applet_no_and_exit(a, argv); + ch = i_getch(input); + nommu_addchr(as_string, ch); +# if ENABLE_SH_MATH_SUPPORT + if (i_peek(input) == '(') { + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, /*quote_mask |*/ '+'); + if (!BB_MMU) + pos = dest->length; + add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG); + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, ')'); + o_addchr(as_string, ')'); } -# endif - /* Re-exec ourselves */ - debug_printf_exec("re-execing applet '%s'\n", argv[0]); - sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); - execv(bb_busybox_exec_path, argv); - /* If they called chroot or otherwise made the binary no longer - * executable, fall through */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; } +# endif +# if ENABLE_HUSH_TICK + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, quote_mask | '`'); + if (!BB_MMU) + pos = dest->length; + add_till_closing_bracket(dest, input, ')'); + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, ')'); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); +# endif + break; } #endif - -#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU - skip: -#endif - execvp_or_die(argv); -} - -/* Called after [v]fork() in run_pipe - */ -static void pseudo_exec(nommu_save_t *nommu_save, - struct command *command, - char **argv_expanded) NORETURN; -static void pseudo_exec(nommu_save_t *nommu_save, - struct command *command, - char **argv_expanded) -{ - if (command->argv) { - pseudo_exec_argv(nommu_save, command->argv, - command->assignment_cnt, argv_expanded); - } - - if (command->group) { - /* Cases when we are here: - * ( list ) - * { list } & - * ... | ( list ) | ... - * ... | { list } | ... - */ -#if BB_MMU - int rcode; - debug_printf_exec("pseudo_exec: run_list\n"); - reset_traps_to_defaults(); - rcode = run_list(command->group); - /* OK to leak memory by not calling free_pipe_list, - * since this process is about to exit */ - _exit(rcode); -#else - re_execute_shell(&nommu_save->argv_from_re_execing, - command->group_as_string, - G.global_argv[0], - G.global_argv + 1, - NULL); -#endif + case '_': + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek(input); + if (isalnum(ch)) { /* it's $_name or $_123 */ + ch = '_'; + goto make_var; + } + /* else: it's $_ */ + /* TODO: $_ and $-: */ + /* $_ Shell or shell script name; or last argument of last command + * (if last command wasn't a pipe; if it was, bash sets $_ to ""); + * but in command's env, set to full pathname used to invoke it */ + /* $- Option flags set by set builtin or shell options (-i etc) */ + default: + o_addQchr(dest, '$'); } - - /* Case when we are here: ... | >file */ - debug_printf_exec("pseudo_exec'ed null command\n"); - _exit(EXIT_SUCCESS); + debug_printf_parse("parse_dollar return 0\n"); + return 0; +#undef as_string } -#if ENABLE_HUSH_JOB -static const char *get_cmdtext(struct pipe *pi) +#if BB_MMU +#define parse_stream_dquoted(as_string, dest, input, dquote_end) \ + parse_stream_dquoted(dest, input, dquote_end) +#define as_string NULL +#endif +static int parse_stream_dquoted(o_string *as_string, + o_string *dest, + struct in_str *input, + int dquote_end) { - char **argv; - char *p; - int len; + int ch; + int next; - /* This is subtle. ->cmdtext is created only on first backgrounding. - * (Think "cat, , fg, , fg, ...." here...) - * On subsequent bg argv is trashed, but we won't use it */ - if (pi->cmdtext) - return pi->cmdtext; - argv = pi->cmds[0].argv; - if (!argv || !argv[0]) { - pi->cmdtext = xzalloc(1); - return pi->cmdtext; + again: + ch = i_getch(input); + if (ch != EOF) + nommu_addchr(as_string, ch); + if (ch == dquote_end) { /* may be only '"' or EOF */ + if (dest->o_assignment == NOT_ASSIGNMENT) + dest->o_escape ^= 1; + debug_printf_parse("parse_stream_dquoted return 0\n"); + return 0; } - - len = 0; - do { - len += strlen(*argv) + 1; - } while (*++argv); - p = xmalloc(len); - pi->cmdtext = p; - argv = pi->cmds[0].argv; - do { - len = strlen(*argv); - memcpy(p, *argv, len); - p += len; - *p++ = ' '; - } while (*++argv); - p[-1] = '\0'; - return pi->cmdtext; -} - -static void insert_bg_job(struct pipe *pi) -{ - struct pipe *job, **jobp; - int i; - - /* Linear search for the ID of the job to use */ - pi->jobid = 1; - for (job = G.job_list; job; job = job->next) - if (job->jobid >= pi->jobid) - pi->jobid = job->jobid + 1; - - /* Add job to the list of running jobs */ - jobp = &G.job_list; - while ((job = *jobp) != NULL) - jobp = &job->next; - job = *jobp = xmalloc(sizeof(*job)); - - *job = *pi; /* physical copy */ - job->next = NULL; - job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); - /* Cannot copy entire pi->cmds[] vector! This causes double frees */ - for (i = 0; i < pi->num_cmds; i++) { - job->cmds[i].pid = pi->cmds[i].pid; - /* all other fields are not used and stay zero */ + /* note: can't move it above ch == dquote_end check! */ + if (ch == EOF) { + syntax_error_unterm_ch('"'); + /*xfunc_die(); - redundant */ } - job->cmdtext = xstrdup(get_cmdtext(pi)); - - if (G_interactive_fd) - printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext); - G.last_jobid = job->jobid; + next = '\0'; + if (ch != '\n') { + next = i_peek(input); + } + debug_printf_parse("\" ch=%c (%d) escape=%d\n", + ch, ch, dest->o_escape); + if (ch == '\\') { + if (next == EOF) { + syntax_error("\\"); + xfunc_die(); + } + /* bash: + * "The backslash retains its special meaning [in "..."] + * only when followed by one of the following characters: + * $, `, ", \, or . A double quote may be quoted + * within double quotes by preceding it with a backslash." + */ + if (strchr("$`\"\\\n", next) != NULL) { + ch = i_getch(input); + if (ch != '\n') { + o_addqchr(dest, ch); + nommu_addchr(as_string, ch); + } + } else { + o_addqchr(dest, '\\'); + nommu_addchr(as_string, '\\'); + } + goto again; + } + if (ch == '$') { + if (parse_dollar(as_string, dest, input) != 0) { + debug_printf_parse("parse_stream_dquoted return 1: " + "parse_dollar returned non-0\n"); + return 1; + } + goto again; + } +#if ENABLE_HUSH_TICK + if (ch == '`') { + //unsigned pos = dest->length; + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, 0x80 | '`'); + add_till_backquote(dest, input); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + goto again; + } +#endif + o_addQchr(dest, ch); + if (ch == '=' + && (dest->o_assignment == MAYBE_ASSIGNMENT + || dest->o_assignment == WORD_IS_KEYWORD) + && is_well_formed_var_name(dest->data, '=') + ) { + dest->o_assignment = DEFINITELY_ASSIGNMENT; + } + goto again; +#undef as_string } -static void remove_bg_job(struct pipe *pi) +/* + * Scan input until EOF or end_trigger char. + * Return a list of pipes to execute, or NULL on EOF + * or if end_trigger character is met. + * On syntax error, exit is shell is not interactive, + * reset parsing machinery and start parsing anew, + * or return ERR_PTR. + */ +static struct pipe *parse_stream(char **pstring, + struct in_str *input, + int end_trigger) { - struct pipe *prev_pipe; + struct parse_context ctx; + o_string dest = NULL_O_STRING; + int is_in_dquote; + int heredoc_cnt; - if (pi == G.job_list) { - G.job_list = pi->next; - } else { - prev_pipe = G.job_list; - while (prev_pipe->next != pi) - prev_pipe = prev_pipe->next; - prev_pipe->next = pi->next; - } - if (G.job_list) - G.last_jobid = G.job_list->jobid; - else - G.last_jobid = 0; -} + /* Double-quote state is handled in the state variable is_in_dquote. + * A single-quote triggers a bypass of the main loop until its mate is + * found. When recursing, quote state is passed in via dest->o_escape. + */ + debug_printf_parse("parse_stream entered, end_trigger='%c'\n", + end_trigger ? end_trigger : 'X'); + debug_enter(); -/* Remove a backgrounded job */ -static void delete_finished_bg_job(struct pipe *pi) -{ - remove_bg_job(pi); - pi->stopped_cmds = 0; - free_pipe(pi); - free(pi); -} -#endif /* JOB */ + /* If very first arg is "" or '', dest.data may end up NULL. + * Preventing this: */ + o_addchr(&dest, '\0'); + dest.length = 0; -/* Check to see if any processes have exited -- if they - * have, figure out why and see if a job has completed */ -static int checkjobs(struct pipe* fg_pipe) -{ - int attributes; - int status; -#if ENABLE_HUSH_JOB - struct pipe *pi; + G.ifs = get_local_var_value("IFS"); + if (G.ifs == NULL) + G.ifs = defifs; + + reset: +#if ENABLE_HUSH_INTERACTIVE + input->promptmode = 0; /* PS1 */ #endif - pid_t childpid; - int rcode = 0; + /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */ + initialize_context(&ctx); + is_in_dquote = 0; + heredoc_cnt = 0; + while (1) { + const char *is_ifs; + const char *is_special; + int ch; + int next; + int redir_fd; + redir_type redir_style; - debug_printf_jobs("checkjobs %p\n", fg_pipe); + if (is_in_dquote) { + /* dest.has_quoted_part = 1; - already is (see below) */ + if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) { + goto parse_error; + } + /* We reached closing '"' */ + is_in_dquote = 0; + } + ch = i_getch(input); + debug_printf_parse(": ch=%c (%d) escape=%d\n", + ch, ch, dest.o_escape); + if (ch == EOF) { + struct pipe *pi; - attributes = WUNTRACED; - if (fg_pipe == NULL) - attributes |= WNOHANG; + if (heredoc_cnt) { + syntax_error_unterm_str("here document"); + goto parse_error; + } + /* end_trigger == '}' case errors out earlier, + * checking only ')' */ + if (end_trigger == ')') { + syntax_error_unterm_ch('('); /* exits */ + /* goto parse_error; */ + } - errno = 0; -#if ENABLE_HUSH_FAST - if (G.handled_SIGCHLD == G.count_SIGCHLD) { -//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p", -//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe); - /* There was neither fork nor SIGCHLD since last waitpid */ - /* Avoid doing waitpid syscall if possible */ - if (!G.we_have_children) { - errno = ECHILD; - return -1; - } - if (fg_pipe == NULL) { /* is WNOHANG set? */ - /* We have children, but they did not exit - * or stop yet (we saw no SIGCHLD) */ - return 0; - } - /* else: !WNOHANG, waitpid will block, can't short-circuit */ - } + if (done_word(&dest, &ctx)) { + goto parse_error; + } + o_free(&dest); + done_pipe(&ctx, PIPE_SEQ); + pi = ctx.list_head; + /* If we got nothing... */ + /* (this makes bare "&" cmd a no-op. + * bash says: "syntax error near unexpected token '&'") */ + if (pi->num_cmds == 0 + IF_HAS_KEYWORDS( && pi->res_word == RES_NONE) + ) { + free_pipe_list(pi); + pi = NULL; + } +#if !BB_MMU + debug_printf_parse("as_string '%s'\n", ctx.as_string.data); + if (pstring) + *pstring = ctx.as_string.data; + else + o_free_unsafe(&ctx.as_string); #endif + debug_leave(); + debug_printf_parse("parse_stream return %p\n", pi); + return pi; + } + nommu_addchr(&ctx.as_string, ch); -/* Do we do this right? - * bash-3.00# sleep 20 | false - * - * [3]+ Stopped sleep 20 | false - * bash-3.00# echo $? - * 1 <========== bg pipe is not fully done, but exitcode is already known! - * [hush 1.14.0: yes we do it right] - */ - wait_more: - while (1) { - int i; - int dead; + next = '\0'; + if (ch != '\n') + next = i_peek(input); -#if ENABLE_HUSH_FAST - i = G.count_SIGCHLD; -#endif - childpid = waitpid(-1, &status, attributes); - if (childpid <= 0) { - if (childpid && errno != ECHILD) - bb_perror_msg("waitpid"); -#if ENABLE_HUSH_FAST - else { /* Until next SIGCHLD, waitpid's are useless */ - G.we_have_children = (childpid == 0); - G.handled_SIGCHLD = i; -//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + is_special = "{}<>;&|()#'" /* special outside of "str" */ + "\\$\"" IF_HUSH_TICK("`"); /* always special */ + /* Are { and } special here? */ + if (ctx.command->argv /* word [word]{... - non-special */ + || dest.length /* word{... - non-special */ + || dest.has_quoted_part /* ""{... - non-special */ + || (next != ';' /* }; - special */ + && next != ')' /* }) - special */ + && next != '&' /* }& and }&& ... - special */ + && next != '|' /* }|| ... - special */ + && !strchr(G.ifs, next) /* {word - non-special */ + ) + ) { + /* They are not special, skip "{}" */ + is_special += 2; + } + is_special = strchr(is_special, ch); + is_ifs = strchr(G.ifs, ch); + + if (!is_special && !is_ifs) { /* ordinary char */ + ordinary_char: + o_addQchr(&dest, ch); + if ((dest.o_assignment == MAYBE_ASSIGNMENT + || dest.o_assignment == WORD_IS_KEYWORD) + && ch == '=' + && is_well_formed_var_name(dest.data, '=') + ) { + dest.o_assignment = DEFINITELY_ASSIGNMENT; } -#endif - break; + continue; } - dead = WIFEXITED(status) || WIFSIGNALED(status); -#if DEBUG_JOBS - if (WIFSTOPPED(status)) - debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", - childpid, WSTOPSIG(status), WEXITSTATUS(status)); - if (WIFSIGNALED(status)) - debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", - childpid, WTERMSIG(status), WEXITSTATUS(status)); - if (WIFEXITED(status)) - debug_printf_jobs("pid %d exited, exitcode %d\n", - childpid, WEXITSTATUS(status)); -#endif - /* Were we asked to wait for fg pipe? */ - if (fg_pipe) { - for (i = 0; i < fg_pipe->num_cmds; i++) { - debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); - if (fg_pipe->cmds[i].pid != childpid) + if (is_ifs) { + if (done_word(&dest, &ctx)) { + goto parse_error; + } + if (ch == '\n') { +#if ENABLE_HUSH_CASE + /* "case ... in word) ..." - + * newlines are ignored (but ';' wouldn't be) */ + if (ctx.command->argv == NULL + && ctx.ctx_res_w == RES_MATCH + ) { continue; - if (dead) { - fg_pipe->cmds[i].pid = 0; - fg_pipe->alive_cmds--; - if (i == fg_pipe->num_cmds - 1) { - /* last process gives overall exitstatus */ - rcode = WEXITSTATUS(status); - /* bash prints killer signal's name for *last* - * process in pipe (prints just newline for SIGINT). - * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT) - */ - if (WIFSIGNALED(status)) { - int sig = WTERMSIG(status); - printf("%s\n", sig == SIGINT ? "" : get_signame(sig)); - /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here? - * Maybe we need to use sig | 128? */ - rcode = sig + 128; - } - IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;) + } +#endif + /* Treat newline as a command separator. */ + done_pipe(&ctx, PIPE_SEQ); + debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt); + if (heredoc_cnt) { + if (fetch_heredocs(heredoc_cnt, &ctx, input)) { + goto parse_error; } - } else { - fg_pipe->cmds[i].is_stopped = 1; - fg_pipe->stopped_cmds++; + heredoc_cnt = 0; } - debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", - fg_pipe->alive_cmds, fg_pipe->stopped_cmds); - if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) { - /* All processes in fg pipe have exited or stopped */ -/* Note: *non-interactive* bash does not continue if all processes in fg pipe - * are stopped. Testcase: "cat | cat" in a script (not on command line!) - * and "killall -STOP cat" */ - if (G_interactive_fd) { -#if ENABLE_HUSH_JOB - if (fg_pipe->alive_cmds) - insert_bg_job(fg_pipe); + dest.o_assignment = MAYBE_ASSIGNMENT; + ch = ';'; + /* note: if (is_ifs) continue; + * will still trigger for us */ + } + } + + /* "cmd}" or "cmd }..." without semicolon or &: + * } is an ordinary char in this case, even inside { cmd; } + * Pathological example: { ""}; } should exec "}" cmd + */ + if (ch == '}') { + if (!IS_NULL_CMD(ctx.command) /* cmd } */ + || dest.length != 0 /* word} */ + || dest.has_quoted_part /* ""} */ + ) { + goto ordinary_char; + } + if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */ + goto skip_end_trigger; + /* else: } does terminate a group */ + } + + if (end_trigger && end_trigger == ch + && (ch != ';' || heredoc_cnt == 0) +#if ENABLE_HUSH_CASE + && (ch != ')' + || ctx.ctx_res_w != RES_MATCH + || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0) + ) +#endif + ) { + if (heredoc_cnt) { + /* This is technically valid: + * { cat <alive_cmds) - return rcode; - } - /* There are still running processes in the fg pipe */ - goto wait_more; /* do waitpid again */ + debug_leave(); + debug_printf_parse("parse_stream return %p: " + "end_trigger char found\n", + ctx.list_head); + return ctx.list_head; } - /* it wasnt fg_pipe, look for process in bg pipes */ } + skip_end_trigger: + if (is_ifs) + continue; -#if ENABLE_HUSH_JOB - /* We asked to wait for bg or orphaned children */ - /* No need to remember exitcode in this case */ - for (pi = G.job_list; pi; pi = pi->next) { - for (i = 0; i < pi->num_cmds; i++) { - if (pi->cmds[i].pid == childpid) - goto found_pi_and_prognum; + /* Catch <, > before deciding whether this word is + * an assignment. a=1 2>z b=2: b=2 is still assignment */ + switch (ch) { + case '>': + redir_fd = redirect_opt_num(&dest); + if (done_word(&dest, &ctx)) { + goto parse_error; } - } - /* Happens when shell is used as init process (init=/bin/sh) */ - debug_printf("checkjobs: pid %d was not in our list!\n", childpid); - continue; /* do waitpid again */ - - found_pi_and_prognum: - if (dead) { - /* child exited */ - pi->cmds[i].pid = 0; - pi->alive_cmds--; - if (!pi->alive_cmds) { - if (G_interactive_fd) - printf(JOB_STATUS_FORMAT, pi->jobid, - "Done", pi->cmdtext); - delete_finished_bg_job(pi); + redir_style = REDIRECT_OVERWRITE; + if (next == '>') { + redir_style = REDIRECT_APPEND; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } +#if 0 + else if (next == '(') { + syntax_error(">(process) not supported"); + goto parse_error; } - } else { - /* child stopped */ - pi->cmds[i].is_stopped = 1; - pi->stopped_cmds++; - } -#endif - } /* while (waitpid succeeds)... */ - - return rcode; -} - -#if ENABLE_HUSH_JOB -static int checkjobs_and_fg_shell(struct pipe* fg_pipe) -{ - pid_t p; - int rcode = checkjobs(fg_pipe); - if (G_saved_tty_pgrp) { - /* Job finished, move the shell to the foreground */ - p = getpgrp(); /* our process group id */ - debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p); - tcsetpgrp(G_interactive_fd, p); - } - return rcode; -} #endif - -/* Start all the jobs, but don't wait for anything to finish. - * See checkjobs(). - * - * Return code is normally -1, when the caller has to wait for children - * to finish to determine the exit status of the pipe. If the pipe - * is a simple builtin command, however, the action is done by the - * time run_pipe returns, and the exit code is provided as the - * return value. - * - * Returns -1 only if started some children. IOW: we have to - * mask out retvals of builtins etc with 0xff! - * - * The only case when we do not need to [v]fork is when the pipe - * is single, non-backgrounded, non-subshell command. Examples: - * cmd ; ... { list } ; ... - * cmd && ... { list } && ... - * cmd || ... { list } || ... - * If it is, then we can run cmd as a builtin, NOFORK [do we do this?], - * or (if SH_STANDALONE) an applet, and we can run the { list } - * with run_list. If it isn't one of these, we fork and exec cmd. - * - * Cases when we must fork: - * non-single: cmd | cmd - * backgrounded: cmd & { list } & - * subshell: ( list ) [&] - */ -#if !ENABLE_HUSH_MODE_X -#define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \ - redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel) + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error; + continue; /* back to top of while (1) */ + case '<': + redir_fd = redirect_opt_num(&dest); + if (done_word(&dest, &ctx)) { + goto parse_error; + } + redir_style = REDIRECT_INPUT; + if (next == '<') { + redir_style = REDIRECT_HEREDOC; + heredoc_cnt++; + debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt); + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } else if (next == '>') { + redir_style = REDIRECT_IO; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } +#if 0 + else if (next == '(') { + syntax_error("<(process) not supported"); + goto parse_error; + } #endif -static int redirect_and_varexp_helper(char ***new_env_p, struct variable **old_vars_p, struct command *command, int squirrel[3], char **argv_expanded) -{ - /* setup_redirects acts on file descriptors, not FILEs. - * This is perfect for work that comes after exec(). - * Is it really safe for inline use? Experimentally, - * things seem to work. */ - int rcode = setup_redirects(command, squirrel); - if (rcode == 0) { - char **new_env = expand_assignments(command->argv, command->assignment_cnt); - *new_env_p = new_env; - dump_cmd_in_x_mode(new_env); - dump_cmd_in_x_mode(argv_expanded); - if (old_vars_p) - *old_vars_p = set_vars_and_save_old(new_env); - } - return rcode; -} -static NOINLINE int run_pipe(struct pipe *pi) -{ - static const char *const null_ptr = NULL; - - int cmd_no; - int next_infd; - struct command *command; - char **argv_expanded; - char **argv; - /* it is not always needed, but we aim to smaller code */ - int squirrel[] = { -1, -1, -1 }; - int rcode; - - debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds); - debug_enter(); - - IF_HUSH_JOB(pi->pgrp = -1;) - pi->stopped_cmds = 0; - command = &pi->cmds[0]; - argv_expanded = NULL; - - if (pi->num_cmds != 1 - || pi->followup == PIPE_BG - || command->cmd_type == CMD_SUBSHELL - ) { - goto must_fork; - } + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error; + continue; /* back to top of while (1) */ + } - pi->alive_cmds = 1; + if (dest.o_assignment == MAYBE_ASSIGNMENT + /* check that we are not in word in "a=1 2>word b=1": */ + && !ctx.pending_redirect + ) { + /* ch is a special char and thus this word + * cannot be an assignment */ + dest.o_assignment = NOT_ASSIGNMENT; + } - debug_printf_exec(": group:%p argv:'%s'\n", - command->group, command->argv ? command->argv[0] : "NONE"); + /* Note: nommu_addchr(&ctx.as_string, ch) is already done */ - if (command->group) { -#if ENABLE_HUSH_FUNCTIONS - if (command->cmd_type == CMD_FUNCDEF) { - /* "executing" func () { list } */ - struct function *funcp; + switch (ch) { + case '#': + if (dest.length == 0) { + while (1) { + ch = i_peek(input); + if (ch == EOF || ch == '\n') + break; + i_getch(input); + /* note: we do not add it to &ctx.as_string */ + } + nommu_addchr(&ctx.as_string, '\n'); + } else { + o_addQchr(&dest, ch); + } + break; + case '\\': + if (next == EOF) { + syntax_error("\\"); + xfunc_die(); + } + ch = i_getch(input); + if (ch != '\n') { + o_addchr(&dest, '\\'); + /*nommu_addchr(&ctx.as_string, '\\'); - already done */ + o_addchr(&dest, ch); + nommu_addchr(&ctx.as_string, ch); + /* Example: echo Hello \2>file + * we need to know that word 2 is quoted */ + dest.has_quoted_part = 1; + } +#if !BB_MMU + else { + /* It's "\". Remove trailing '\' from ctx.as_string */ + ctx.as_string.data[--ctx.as_string.length] = '\0'; + } +#endif + break; + case '$': + if (parse_dollar(&ctx.as_string, &dest, input) != 0) { + debug_printf_parse("parse_stream parse error: " + "parse_dollar returned non-0\n"); + goto parse_error; + } + break; + case '\'': + dest.has_quoted_part = 1; + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('\''); + /*xfunc_die(); - redundant */ + } + nommu_addchr(&ctx.as_string, ch); + if (ch == '\'') + break; + o_addqchr(&dest, ch); + } + break; + case '"': + dest.has_quoted_part = 1; + is_in_dquote ^= 1; /* invert */ + if (dest.o_assignment == NOT_ASSIGNMENT) + dest.o_escape ^= 1; + break; +#if ENABLE_HUSH_TICK + case '`': { + unsigned pos; - funcp = new_function(command->argv[0]); - /* funcp->name is already set to argv[0] */ - funcp->body = command->group; + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, '`'); + pos = dest.length; + add_till_backquote(&dest, input); # if !BB_MMU - funcp->body_as_string = command->group_as_string; - command->group_as_string = NULL; + o_addstr(&ctx.as_string, dest.data + pos); + o_addchr(&ctx.as_string, '`'); # endif - command->group = NULL; - command->argv[0] = NULL; - debug_printf_exec("cmd %p has child func at %p\n", command, funcp); - funcp->parent_cmd = command; - command->child_func = funcp; - - debug_printf_exec("run_pipe: return EXIT_SUCCESS\n"); - debug_leave(); - return EXIT_SUCCESS; + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos); + break; } #endif - /* { list } */ - debug_printf("non-subshell group\n"); - rcode = 1; /* exitcode if redir failed */ - if (setup_redirects(command, squirrel) == 0) { - debug_printf_exec(": run_list\n"); - rcode = run_list(command->group) & 0xff; - } - restore_redirects(squirrel); - IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) - debug_leave(); - debug_printf_exec("run_pipe: return %d\n", rcode); - return rcode; - } - - argv = command->argv ? command->argv : (char **) &null_ptr; - { - const struct built_in_command *x; -#if ENABLE_HUSH_FUNCTIONS - const struct function *funcp; -#else - enum { funcp = 0 }; + case ';': +#if ENABLE_HUSH_CASE + case_semi: #endif - char **new_env = NULL; - struct variable *old_vars = NULL; - - if (argv[command->assignment_cnt] == NULL) { - /* Assignments, but no command */ - /* Ensure redirects take effect (that is, create files). - * Try "a=t >file" */ -#if 0 /* A few cases in testsuite fail with this code. FIXME */ - rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL); - /* Set shell variables */ - if (new_env) { - argv = new_env; - while (*argv) { - set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); - /* Do we need to flag set_local_var() errors? - * "assignment to readonly var" and "putenv error" - */ - argv++; - } + if (done_word(&dest, &ctx)) { + goto parse_error; } - /* Redirect error sets $? to 1. Otherwise, - * if evaluating assignment value set $?, retain it. - * Try "false; q=`exit 2`; echo $?" - should print 2: */ - if (rcode == 0) - rcode = G.last_exitcode; - /* Exit, _skipping_ variable restoring code: */ - goto clean_up_and_ret0; - -#else /* Older, bigger, but more correct code */ - - rcode = setup_redirects(command, squirrel); - restore_redirects(squirrel); - /* Set shell variables */ - if (G_x_mode) - bb_putchar_stderr('+'); - while (*argv) { - char *p = expand_string_to_string(*argv); - if (G_x_mode) - fprintf(stderr, " %s", p); - debug_printf_exec("set shell var:'%s'->'%s'\n", - *argv, p); - set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); - /* Do we need to flag set_local_var() errors? - * "assignment to readonly var" and "putenv error" - */ - argv++; + done_pipe(&ctx, PIPE_SEQ); +#if ENABLE_HUSH_CASE + /* Eat multiple semicolons, detect + * whether it means something special */ + while (1) { + ch = i_peek(input); + if (ch != ';') + break; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + if (ctx.ctx_res_w == RES_CASE_BODY) { + ctx.ctx_dsemicolon = 1; + ctx.ctx_res_w = RES_MATCH; + break; + } } - if (G_x_mode) - bb_putchar_stderr('\n'); - /* Redirect error sets $? to 1. Otherwise, - * if evaluating assignment value set $?, retain it. - * Try "false; q=`exit 2`; echo $?" - should print 2: */ - if (rcode == 0) - rcode = G.last_exitcode; - IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) - debug_leave(); - debug_printf_exec("run_pipe: return %d\n", rcode); - return rcode; #endif - } - - /* Expand the rest into (possibly) many strings each */ - if (0) {} -#if ENABLE_HUSH_BASH_COMPAT - else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) { - argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt); - } + new_cmd: + /* We just finished a cmd. New one may start + * with an assignment */ + dest.o_assignment = MAYBE_ASSIGNMENT; + break; + case '&': + if (done_word(&dest, &ctx)) { + goto parse_error; + } + if (next == '&') { + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_AND); + } else { + done_pipe(&ctx, PIPE_BG); + } + goto new_cmd; + case '|': + if (done_word(&dest, &ctx)) { + goto parse_error; + } +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + break; /* we are in case's "word | word)" */ #endif -#ifdef CMD_SINGLEWORD_NOGLOB_COND - else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) { - argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt); - } + if (next == '|') { /* || */ + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_OR); + } else { + /* we could pick up a file descriptor choice here + * with redirect_opt_num(), but bash doesn't do it. + * "echo foo 2| cat" yields "foo 2". */ + done_command(&ctx); +#if !BB_MMU + o_reset_to_empty_unquoted(&ctx.as_string); #endif - else { - argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt); - } - - /* if someone gives us an empty string: `cmd with empty output` */ - if (!argv_expanded[0]) { - free(argv_expanded); - debug_leave(); - return G.last_exitcode; - } - - x = find_builtin(argv_expanded[0]); -#if ENABLE_HUSH_FUNCTIONS - funcp = NULL; - if (!x) - funcp = find_function(argv_expanded[0]); + } + goto new_cmd; + case '(': +#if ENABLE_HUSH_CASE + /* "case... in [(]word)..." - skip '(' */ + if (ctx.ctx_res_w == RES_MATCH + && ctx.command->argv == NULL /* not (word|(... */ + && dest.length == 0 /* not word(... */ + && dest.has_quoted_part == 0 /* not ""(... */ + ) { + continue; + } #endif - if (x || funcp) { - if (!funcp) { - if (x->b_function == builtin_exec && argv_expanded[1] == NULL) { - debug_printf("exec with redirects only\n"); - rcode = setup_redirects(command, NULL); - goto clean_up_and_ret1; - } + case '{': + if (parse_group(&dest, &ctx, input, ch) != 0) { + goto parse_error; } - rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded); - if (rcode == 0) { - if (!funcp) { - debug_printf_exec(": builtin '%s' '%s'...\n", - x->b_cmd, argv_expanded[1]); - rcode = x->b_function(argv_expanded) & 0xff; - fflush_all(); - } -#if ENABLE_HUSH_FUNCTIONS - else { -# if ENABLE_HUSH_LOCAL - struct variable **sv; - sv = G.shadowed_vars_pp; - G.shadowed_vars_pp = &old_vars; -# endif - debug_printf_exec(": function '%s' '%s'...\n", - funcp->name, argv_expanded[1]); - rcode = run_function(funcp, argv_expanded) & 0xff; -# if ENABLE_HUSH_LOCAL - G.shadowed_vars_pp = sv; -# endif - } + goto new_cmd; + case ')': +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + goto case_semi; #endif - } - clean_up_and_ret: - unset_vars(new_env); - add_vars(old_vars); -/* clean_up_and_ret0: */ - restore_redirects(squirrel); - clean_up_and_ret1: - free(argv_expanded); - IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) - debug_leave(); - debug_printf_exec("run_pipe return %d\n", rcode); - return rcode; + case '}': + /* proper use of this character is caught by end_trigger: + * if we see {, we call parse_group(..., end_trigger='}') + * and it will match } earlier (not here). */ + syntax_error_unexpected_ch(ch); + goto parse_error; + default: + if (HUSH_DEBUG) + bb_error_msg_and_die("BUG: unexpected %c\n", ch); } + } /* while (1) */ - if (ENABLE_FEATURE_SH_STANDALONE) { - int n = find_applet_by_name(argv_expanded[0]); - if (n >= 0 && APPLET_IS_NOFORK(n)) { - rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded); - if (rcode == 0) { - debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", - argv_expanded[0], argv_expanded[1]); - rcode = run_nofork_applet(n, argv_expanded); - } - goto clean_up_and_ret; + parse_error: + { + struct parse_context *pctx; + IF_HAS_KEYWORDS(struct parse_context *p2;) + + /* Clean up allocated tree. + * Sample for finding leaks on syntax error recovery path. + * Run it from interactive shell, watch pmap `pidof hush`. + * while if false; then false; fi; do break; fi + * Samples to catch leaks at execution: + * while if (true | {true;}); then echo ok; fi; do break; done + * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done + */ + pctx = &ctx; + do { + /* Update pipe/command counts, + * otherwise freeing may miss some */ + done_pipe(pctx, PIPE_SEQ); + debug_printf_clean("freeing list %p from ctx %p\n", + pctx->list_head, pctx); + debug_print_tree(pctx->list_head, 0); + free_pipe_list(pctx->list_head); + debug_printf_clean("freed list %p\n", pctx->list_head); +#if !BB_MMU + o_free_unsafe(&pctx->as_string); +#endif + IF_HAS_KEYWORDS(p2 = pctx->stack;) + if (pctx != &ctx) { + free(pctx); } + IF_HAS_KEYWORDS(pctx = p2;) + } while (HAS_KEYWORDS && pctx); + /* Free text, clear all dest fields */ + o_free(&dest); + /* If we are not in top-level parse, we return, + * our caller will propagate error. + */ + if (end_trigger != ';') { +#if !BB_MMU + if (pstring) + *pstring = NULL; +#endif + debug_leave(); + return ERR_PTR; } - /* It is neither builtin nor applet. We must fork. */ + /* Discard cached input, force prompt */ + input->p = NULL; + IF_HUSH_INTERACTIVE(input->promptme = 1;) + goto reset; } +} - must_fork: - /* NB: argv_expanded may already be created, and that - * might include `cmd` runs! Do not rerun it! We *must* - * use argv_expanded if it's non-NULL */ - /* Going to fork a child per each pipe member */ - pi->alive_cmds = 0; - next_infd = 0; +/*** Execution routines ***/ - cmd_no = 0; - while (cmd_no < pi->num_cmds) { - struct fd_pair pipefds; -#if !BB_MMU - volatile nommu_save_t nommu_save; - nommu_save.new_env = NULL; - nommu_save.old_vars = NULL; - nommu_save.argv = NULL; - nommu_save.argv_from_re_execing = NULL; -#endif - command = &pi->cmds[cmd_no]; - cmd_no++; - if (command->argv) { - debug_printf_exec(": pipe member '%s' '%s'...\n", - command->argv[0], command->argv[1]); - } else { - debug_printf_exec(": pipe member with no argv\n"); - } +/* Expansion can recurse, need forward decls: */ +static char *expand_string_to_string(const char *str); +static int process_command_subs(o_string *dest, const char *s); - /* pipes are inserted between pairs of commands */ - pipefds.rd = 0; - pipefds.wr = 1; - if (cmd_no < pi->num_cmds) - xpiped_pair(pipefds); +/* expand_strvec_to_strvec() takes a list of strings, expands + * all variable references within and returns a pointer to + * a list of expanded strings, possibly with larger number + * of strings. (Think VAR="a b"; echo $VAR). + * This new list is allocated as a single malloc block. + * NULL-terminated list of char* pointers is at the beginning of it, + * followed by strings themself. + * Caller can deallocate entire list by single free(list). */ - command->pid = BB_MMU ? fork() : vfork(); - if (!command->pid) { /* child */ -#if ENABLE_HUSH_JOB - disable_restore_tty_pgrp_on_exit(); - CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */ +/* Store given string, finalizing the word and starting new one whenever + * we encounter IFS char(s). This is used for expanding variable values. + * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ +static int expand_on_ifs(o_string *output, int n, const char *str) +{ + while (1) { + int word_len = strcspn(str, G.ifs); + if (word_len) { + if (output->o_escape || !output->o_glob) + o_addQblock(output, str, word_len); + else /* protect backslashes against globbing up :) */ + o_addblock_duplicate_backslash(output, str, word_len); + str += word_len; + } + if (!*str) /* EOL - do not finalize word */ + break; + o_addchr(output, '\0'); + debug_print_list("expand_on_ifs", output, n); + n = o_save_ptr(output, n); + str += strspn(str, G.ifs); /* skip ifs chars */ + } + debug_print_list("expand_on_ifs[1]", output, n); + return n; +} - /* Every child adds itself to new process group - * with pgid == pid_of_first_child_in_pipe */ - if (G.run_list_level == 1 && G_interactive_fd) { - pid_t pgrp; - pgrp = pi->pgrp; - if (pgrp < 0) /* true for 1st process only */ - pgrp = getpid(); - if (setpgid(0, pgrp) == 0 - && pi->followup != PIPE_BG - && G_saved_tty_pgrp /* we have ctty */ - ) { - /* We do it in *every* child, not just first, - * to avoid races */ - tcsetpgrp(G_interactive_fd, pgrp); - } - } +/* Helper to expand $((...)) and heredoc body. These act as if + * they are in double quotes, with the exception that they are not :). + * Just the rules are similar: "expand only $var and `cmd`" + * + * Returns malloced string. + * As an optimization, we return NULL if expansion is not needed. + */ +static char *expand_pseudo_dquoted(const char *str) +{ + char *exp_str; + struct in_str input; + o_string dest = NULL_O_STRING; + + if (!strchr(str, '$') +#if ENABLE_HUSH_TICK + && !strchr(str, '`') #endif - if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) { - /* 1st cmd in backgrounded pipe - * should have its stdin /dev/null'ed */ - close(0); - if (open(bb_dev_null, O_RDONLY)) - xopen("/", O_RDONLY); - } else { - xmove_fd(next_infd, 0); - } - xmove_fd(pipefds.wr, 1); - if (pipefds.rd > 1) - close(pipefds.rd); - /* Like bash, explicit redirects override pipes, - * and the pipe fd is available for dup'ing. */ - if (setup_redirects(command, NULL)) - _exit(1); + ) { + return NULL; + } - /* Restore default handlers just prior to exec */ - /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */ + /* We need to expand. Example: + * echo $(($a + `echo 1`)) $((1 + $((2)) )) + */ + setup_string_in_str(&input, str); + parse_stream_dquoted(NULL, &dest, &input, EOF); + //bb_error_msg("'%s' -> '%s'", str, dest.data); + exp_str = expand_string_to_string(dest.data); + //bb_error_msg("'%s' -> '%s'", dest.data, exp_str); + o_free_unsafe(&dest); + return exp_str; +} - /* Stores to nommu_save list of env vars putenv'ed - * (NOMMU, on MMU we don't need that) */ - /* cast away volatility... */ - pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded); - /* pseudo_exec() does not return */ - } +#if ENABLE_SH_MATH_SUPPORT +static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p) +{ + arith_eval_hooks_t hooks; + arith_t res; + char *exp_str; - /* parent or error */ -#if ENABLE_HUSH_FAST - G.count_SIGCHLD++; -//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); -#endif - enable_restore_tty_pgrp_on_exit(); -#if !BB_MMU - /* Clean up after vforked child */ - free(nommu_save.argv); - free(nommu_save.argv_from_re_execing); - unset_vars(nommu_save.new_env); - add_vars(nommu_save.old_vars); -#endif - free(argv_expanded); - argv_expanded = NULL; - if (command->pid < 0) { /* [v]fork failed */ - /* Clearly indicate, was it fork or vfork */ - bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork"); - } else { - pi->alive_cmds++; -#if ENABLE_HUSH_JOB - /* Second and next children need to know pid of first one */ - if (pi->pgrp < 0) - pi->pgrp = command->pid; + hooks.lookupvar = get_local_var_value; + hooks.setvar = set_local_var_from_halves; + hooks.endofname = endofname; + exp_str = expand_pseudo_dquoted(arg); + res = arith(exp_str ? exp_str : arg, errcode_p, &hooks); + free(exp_str); + return res; +} #endif - } - if (cmd_no > 1) - close(next_infd); - if (cmd_no < pi->num_cmds) - close(pipefds.wr); - /* Pass read (output) pipe end to next iteration */ - next_infd = pipefds.rd; +#if ENABLE_HUSH_BASH_COMPAT +/* ${var/[/]pattern[/repl]} helpers */ +static char *strstr_pattern(char *val, const char *pattern, int *size) +{ + while (1) { + char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF); + debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end); + if (end) { + *size = end - val; + return val; + } + if (*val == '\0') + return NULL; + /* Optimization: if "*pat" did not match the start of "string", + * we know that "tring", "ring" etc will not match too: + */ + if (pattern[0] == '*') + return NULL; + val++; } +} +static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op) +{ + char *result = NULL; + unsigned res_len = 0; + unsigned repl_len = strlen(repl); - if (!pi->alive_cmds) { - debug_leave(); - debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n"); - return 1; - } + while (1) { + int size; + char *s = strstr_pattern(val, pattern, &size); + if (!s) + break; - debug_leave(); - debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds); - return -1; + result = xrealloc(result, res_len + (s - val) + repl_len + 1); + memcpy(result + res_len, val, s - val); + res_len += s - val; + strcpy(result + res_len, repl); + res_len += repl_len; + debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result); + + val = s + size; + if (exp_op == '/') + break; + } + if (val[0] && result) { + result = xrealloc(result, res_len + strlen(val) + 1); + strcpy(result + res_len, val); + debug_printf_varexp("val:'%s' result:'%s'\n", val, result); + } + debug_printf_varexp("result:'%s'\n", result); + return result; } +#endif -#ifndef debug_print_tree -static void debug_print_tree(struct pipe *pi, int lvl) +/* Helper: + * Handles varname... construct. + */ +static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp, char first_ch) { - static const char *const PIPE[] = { - [PIPE_SEQ] = "SEQ", - [PIPE_AND] = "AND", - [PIPE_OR ] = "OR" , - [PIPE_BG ] = "BG" , - }; - static const char *RES[] = { - [RES_NONE ] = "NONE" , -# if ENABLE_HUSH_IF - [RES_IF ] = "IF" , - [RES_THEN ] = "THEN" , - [RES_ELIF ] = "ELIF" , - [RES_ELSE ] = "ELSE" , - [RES_FI ] = "FI" , -# endif -# if ENABLE_HUSH_LOOPS - [RES_FOR ] = "FOR" , - [RES_WHILE] = "WHILE", - [RES_UNTIL] = "UNTIL", - [RES_DO ] = "DO" , - [RES_DONE ] = "DONE" , -# endif -# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE - [RES_IN ] = "IN" , -# endif -# if ENABLE_HUSH_CASE - [RES_CASE ] = "CASE" , - [RES_CASE_IN ] = "CASE_IN" , - [RES_MATCH] = "MATCH", - [RES_CASE_BODY] = "CASE_BODY", - [RES_ESAC ] = "ESAC" , -# endif - [RES_XXXX ] = "XXXX" , - [RES_SNTX ] = "SNTX" , - }; - static const char *const CMDTYPE[] = { - "{}", - "()", - "[noglob]", -# if ENABLE_HUSH_FUNCTIONS - "func()", -# endif - }; + const char *val = NULL; + char *to_be_freed = NULL; + char *p = *pp; + char *var; + char first_char; + char exp_op; + char exp_save = exp_save; /* for compiler */ + char *exp_saveptr; /* points to expansion operator */ + char *exp_word = exp_word; /* for compiler */ - int pin, prn; + var = arg; + *p = '\0'; + exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL; + first_char = arg[0] = first_ch & 0x7f; + exp_op = 0; - pin = 0; - while (pi) { - fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "", - pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]); - prn = 0; - while (prn < pi->num_cmds) { - struct command *command = &pi->cmds[prn]; - char **argv = command->argv; + if (first_char == '#' && arg[1] && !exp_saveptr) { + /* handle length expansion ${#var} */ + var++; + exp_op = 'L'; + } else { + /* maybe handle parameter expansion */ + if (exp_saveptr /* if 2nd char is one of expansion operators */ + && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */ + ) { + /* ${?:0}, ${#[:]%0} etc */ + exp_saveptr = var + 1; + } else { + /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */ + exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS); + } + exp_op = exp_save = *exp_saveptr; + if (exp_op) { + exp_word = exp_saveptr + 1; + if (exp_op == ':') { + exp_op = *exp_word++; + if (ENABLE_HUSH_BASH_COMPAT + && (exp_op == '\0' || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op)) + ) { + /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */ + exp_op = ':'; + exp_word--; + } + } + *exp_saveptr = '\0'; + } /* else: it's not an expansion op, but bare ${var} */ + } - fprintf(stderr, "%*s cmd %d assignment_cnt:%d", - lvl*2, "", prn, - command->assignment_cnt); - if (command->group) { - fprintf(stderr, " group %s: (argv=%p)%s%s\n", - CMDTYPE[command->cmd_type], - argv -# if !BB_MMU - , " group_as_string:", command->group_as_string -# else - , "", "" -# endif - ); - debug_print_tree(command->group, lvl+1); - prn++; - continue; + /* lookup the variable in question */ + if (isdigit(var[0])) { + /* parse_dollar() should have vetted var for us */ + int n = xatoi_positive(var); + if (n < G.global_argc) + val = G.global_argv[n]; + /* else val remains NULL: $N with too big N */ + } else { + switch (var[0]) { + case '$': /* pid */ + val = utoa(G.root_pid); + break; + case '!': /* bg pid */ + val = G.last_bg_pid ? utoa(G.last_bg_pid) : ""; + break; + case '?': /* exitcode */ + val = utoa(G.last_exitcode); + break; + case '#': /* argc */ + val = utoa(G.global_argc ? G.global_argc-1 : 0); + break; + default: + val = get_local_var_value(var); + } + } + + /* Handle any expansions */ + if (exp_op == 'L') { + debug_printf_expand("expand: length(%s)=", val); + val = utoa(val ? strlen(val) : 0); + debug_printf_expand("%s\n", val); + } else if (exp_op) { + if (exp_op == '%' || exp_op == '#') { + /* Standard-mandated substring removal ops: + * ${parameter%word} - remove smallest suffix pattern + * ${parameter%%word} - remove largest suffix pattern + * ${parameter#word} - remove smallest prefix pattern + * ${parameter##word} - remove largest prefix pattern + * + * Word is expanded to produce a glob pattern. + * Then var's value is matched to it and matching part removed. + */ + if (val && val[0]) { + char *exp_exp_word; + char *loc; + unsigned scan_flags = pick_scan(exp_op, *exp_word); + if (exp_op == *exp_word) /* ## or %% */ + exp_word++; +//TODO: avoid xstrdup unless needed +// (see HACK ALERT below) + val = to_be_freed = xstrdup(val); + exp_exp_word = expand_pseudo_dquoted(exp_word); + if (exp_exp_word) + exp_word = exp_exp_word; + loc = scan_and_match(to_be_freed, exp_word, scan_flags); + //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'", + // exp_op, to_be_freed, exp_word, loc); + free(exp_exp_word); + if (loc) { /* match was found */ + if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */ + val = loc; + else /* %[%] */ + *loc = '\0'; + } } - if (argv) while (*argv) { - fprintf(stderr, " '%s'", *argv); - argv++; + } +#if ENABLE_HUSH_BASH_COMPAT + else if (exp_op == '/' || exp_op == '\\') { + /* Empty variable always gives nothing: */ + // "v=''; echo ${v/*/w}" prints "" + if (val && val[0]) { + /* It's ${var/[/]pattern[/repl]} thing */ + char *pattern, *repl, *t; + pattern = expand_pseudo_dquoted(exp_word); + if (!pattern) + pattern = xstrdup(exp_word); + debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern); + *p++ = SPECIAL_VAR_SYMBOL; + exp_word = p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + *p = '\0'; + repl = expand_pseudo_dquoted(exp_word); + debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl); + /* HACK ALERT. We depend here on the fact that + * G.global_argv and results of utoa and get_local_var_value + * are actually in writable memory: + * replace_pattern momentarily stores NULs there. */ + t = (char*)val; + to_be_freed = replace_pattern(t, + pattern, + (repl ? repl : exp_word), + exp_op); + if (to_be_freed) /* at least one replace happened */ + val = to_be_freed; + free(pattern); + free(repl); } - fprintf(stderr, "\n"); - prn++; } - pi = pi->next; - pin++; - } -} -#endif /* debug_print_tree */ - -/* NB: called by pseudo_exec, and therefore must not modify any - * global data until exec/_exit (we can be a child after vfork!) */ -static int run_list(struct pipe *pi) -{ -#if ENABLE_HUSH_CASE - char *case_word = NULL; -#endif -#if ENABLE_HUSH_LOOPS - struct pipe *loop_top = NULL; - char **for_lcur = NULL; - char **for_list = NULL; -#endif - smallint last_followup; - smalluint rcode; -#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE - smalluint cond_code = 0; -#else - enum { cond_code = 0 }; -#endif -#if HAS_KEYWORDS - smallint rword; /* enum reserved_style */ - smallint last_rword; /* ditto */ #endif + else if (exp_op == ':') { +#if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT + /* It's ${var:N[:M]} bashism. + * Note that in encoded form it has TWO parts: + * var:NM + */ + arith_t beg, len; + int errcode = 0; - debug_printf_exec("run_list start lvl %d\n", G.run_list_level); - debug_enter(); + beg = expand_and_evaluate_arith(exp_word, &errcode); + debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg); + *p++ = SPECIAL_VAR_SYMBOL; + exp_word = p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + *p = '\0'; + len = expand_and_evaluate_arith(exp_word, &errcode); + debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len); -#if ENABLE_HUSH_LOOPS - /* Check syntax for "for" */ - for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) { - if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN) - continue; - /* current word is FOR or IN (BOLD in comments below) */ - if (cpipe->next == NULL) { - syntax_error("malformed for"); - debug_leave(); - debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); - return 1; - } - /* "FOR v; do ..." and "for v IN a b; do..." are ok */ - if (cpipe->next->res_word == RES_DO) - continue; - /* next word is not "do". It must be "in" then ("FOR v in ...") */ - if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */ - || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */ - ) { - syntax_error("malformed for"); - debug_leave(); - debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); - return 1; - } - } + if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */ + if (beg < 0) /* bash compat */ + beg = 0; + debug_printf_varexp("from val:'%s'\n", val); + if (len == 0 || !val || beg >= strlen(val)) + val = ""; + else { + /* Paranoia. What if user entered 9999999999999 + * which fits in arith_t but not int? */ + if (len >= INT_MAX) + len = INT_MAX; + val = to_be_freed = xstrndup(val + beg, len); + } + debug_printf_varexp("val:'%s'\n", val); + } else #endif + { + die_if_script("malformed ${%s:...}", var); + val = ""; + } + } else { /* one of "-=+?" */ + /* Standard-mandated substitution ops: + * ${var?word} - indicate error if unset + * If var is unset, word (or a message indicating it is unset + * if word is null) is written to standard error + * and the shell exits with a non-zero exit status. + * Otherwise, the value of var is substituted. + * ${var-word} - use default value + * If var is unset, word is substituted. + * ${var=word} - assign and use default value + * If var is unset, word is assigned to var. + * In all cases, final value of var is substituted. + * ${var+word} - use alternative value + * If var is unset, null is substituted. + * Otherwise, word is substituted. + * + * Word is subjected to tilde expansion, parameter expansion, + * command substitution, and arithmetic expansion. + * If word is not needed, it is not expanded. + * + * Colon forms (${var:-word}, ${var:=word} etc) do the same, + * but also treat null var as if it is unset. + */ + int use_word = (!val || ((exp_save == ':') && !val[0])); + if (exp_op == '+') + use_word = !use_word; + debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op, + (exp_save == ':') ? "true" : "false", use_word); + if (use_word) { + to_be_freed = expand_pseudo_dquoted(exp_word); + if (to_be_freed) + exp_word = to_be_freed; + if (exp_op == '?') { + /* mimic bash message */ + die_if_script("%s: %s", + var, + exp_word[0] ? exp_word : "parameter null or not set" + ); +//TODO: how interactive bash aborts expansion mid-command? + } else { + val = exp_word; + } - /* Past this point, all code paths should jump to ret: label - * in order to return, no direct "return" statements please. - * This helps to ensure that no memory is leaked. */ + if (exp_op == '=') { + /* ${var=[word]} or ${var:=[word]} */ + if (isdigit(var[0]) || var[0] == '#') { + /* mimic bash message */ + die_if_script("$%s: cannot assign in this way", var); + val = NULL; + } else { + char *new_var = xasprintf("%s=%s", var, val); + set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); + } + } + } + } /* one of "-=+?" */ -#if ENABLE_HUSH_JOB - G.run_list_level++; -#endif + *exp_saveptr = exp_save; + } /* if (exp_op) */ -#if HAS_KEYWORDS - rword = RES_NONE; - last_rword = RES_XXXX; -#endif - last_followup = PIPE_SEQ; - rcode = G.last_exitcode; + arg[0] = first_ch; - /* Go through list of pipes, (maybe) executing them. */ - for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) { - if (G.flag_SIGINT) - break; + *pp = p; + *to_be_freed_pp = to_be_freed; + return val; +} - IF_HAS_KEYWORDS(rword = pi->res_word;) - debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n", - rword, cond_code, last_rword); -#if ENABLE_HUSH_LOOPS - if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) - && loop_top == NULL /* avoid bumping G.depth_of_loop twice */ - ) { - /* start of a loop: remember where loop starts */ - loop_top = pi; - G.depth_of_loop++; - } -#endif - /* Still in the same "if...", "then..." or "do..." branch? */ - if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) { - if ((rcode == 0 && last_followup == PIPE_OR) - || (rcode != 0 && last_followup == PIPE_AND) - ) { - /* It is " || CMD" or " && CMD" - * and we should not execute CMD */ - debug_printf_exec("skipped cmd because of || or &&\n"); - last_followup = pi->followup; - continue; - } - } - last_followup = pi->followup; - IF_HAS_KEYWORDS(last_rword = rword;) -#if ENABLE_HUSH_IF - if (cond_code) { - if (rword == RES_THEN) { - /* if false; then ... fi has exitcode 0! */ - G.last_exitcode = rcode = EXIT_SUCCESS; - /* "if THEN cmd": skip cmd */ - continue; - } - } else { - if (rword == RES_ELSE || rword == RES_ELIF) { - /* "if then ... ELSE/ELIF cmd": - * skip cmd and all following ones */ - break; - } - } -#endif -#if ENABLE_HUSH_LOOPS - if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */ - if (!for_lcur) { - /* first loop through for */ +/* Expand all variable references in given string, adding words to list[] + * at n, n+1,... positions. Return updated n (so that list[n] is next one + * to be filled). This routine is extremely tricky: has to deal with + * variables/parameters with whitespace, $* and $@, and constructs like + * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ +static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) +{ + /* or_mask is either 0 (normal case) or 0x80 - + * expansion of right-hand side of assignment == 1-element expand. + * It will also do no globbing, and thus we must not backslash-quote! + */ + char ored_ch; + char *p; - static const char encoded_dollar_at[] ALIGN1 = { - SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0' - }; /* encoded representation of "$@" */ - static const char *const encoded_dollar_at_argv[] = { - encoded_dollar_at, NULL - }; /* argv list with one element: "$@" */ - char **vals; + ored_ch = 0; - vals = (char**)encoded_dollar_at_argv; - if (pi->next->res_word == RES_IN) { - /* if no variable values after "in" we skip "for" */ - if (!pi->next->cmds[0].argv) { - G.last_exitcode = rcode = EXIT_SUCCESS; - debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n"); - break; - } - vals = pi->next->cmds[0].argv; - } /* else: "for var; do..." -> assume "$@" list */ - /* create list of variable values */ - debug_print_strings("for_list made from", vals); - for_list = expand_strvec_to_strvec(vals); - for_lcur = for_list; - debug_print_strings("for_list", for_list); - } - if (!*for_lcur) { - /* "for" loop is over, clean up */ - free(for_list); - for_list = NULL; - for_lcur = NULL; - break; - } - /* Insert next value from for_lcur */ - /* note: *for_lcur already has quotes removed, $var expanded, etc */ - set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); - continue; - } - if (rword == RES_IN) { - continue; /* "for v IN list;..." - "in" has no cmds anyway */ - } - if (rword == RES_DONE) { - continue; /* "done" has no cmds too */ - } + debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask); + debug_print_list("expand_vars_to_list", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[0]", output, n); + + while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { + char first_ch; + int i; + char *to_be_freed = NULL; + const char *val = NULL; +#if ENABLE_HUSH_TICK + o_string subst_result = NULL_O_STRING; #endif -#if ENABLE_HUSH_CASE - if (rword == RES_CASE) { - case_word = expand_strvec_to_string(pi->cmds->argv); - continue; - } - if (rword == RES_MATCH) { - char **argv; +#if ENABLE_SH_MATH_SUPPORT + char arith_buf[sizeof(arith_t)*3 + 2]; +#endif + o_addblock(output, arg, p - arg); + debug_print_list("expand_vars_to_list[1]", output, n); + arg = ++p; + p = strchr(p, SPECIAL_VAR_SYMBOL); - if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */ + first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ + /* "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string) */ + if ((first_ch & 0x7f) != '@') + ored_ch |= first_ch; + + switch (first_ch & 0x7f) { + /* Highest bit in first_ch indicates that var is double-quoted */ + case '*': + case '@': + i = 1; + if (!G.global_argv[i]) break; - /* all prev words didn't match, does this one match? */ - argv = pi->cmds->argv; - while (*argv) { - char *pattern = expand_string_to_string(*argv); - /* TODO: which FNM_xxx flags to use? */ - cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0); - free(pattern); - if (cond_code == 0) { /* match! we will execute this branch */ - free(case_word); /* make future "word)" stop */ - case_word = NULL; - break; + ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ + if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ + smallint sv = output->o_escape; + /* unquoted var's contents should be globbed, so don't escape */ + output->o_escape = 0; + while (G.global_argv[i]) { + n = expand_on_ifs(output, n, G.global_argv[i]); + debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); + if (G.global_argv[i++][0] && G.global_argv[i]) { + /* this argv[] is not empty and not last: + * put terminating NUL, start new word */ + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[2]", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[3]", output, n); + } + } + output->o_escape = sv; + } else + /* If or_mask is nonzero, we handle assignment 'a=....$@.....' + * and in this case should treat it like '$*' - see 'else...' below */ + if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ + while (1) { + o_addQstr(output, G.global_argv[i]); + if (++i >= G.global_argc) + break; + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[4]", output, n); + n = o_save_ptr(output, n); + } + } else { /* quoted $*: add as one word */ + while (1) { + o_addQstr(output, G.global_argv[i]); + if (!G.global_argv[++i]) + break; + if (G.ifs[0]) + o_addchr(output, G.ifs[0]); } - argv++; } - continue; - } - if (rword == RES_CASE_BODY) { /* inside of a case branch */ - if (cond_code != 0) - continue; /* not matched yet, skip this pipe */ - } + break; + case SPECIAL_VAR_SYMBOL: /* */ + /* "Empty variable", used to make "" etc to not disappear */ + arg++; + ored_ch = 0x80; + break; +#if ENABLE_HUSH_TICK + case '`': /* `cmd */ + *p = '\0'; + arg++; + /* Can't just stuff it into output o_string, + * expanded result may need to be globbed + * and $IFS-splitted */ + debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); + G.last_exitcode = process_command_subs(&subst_result, arg); + debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data); + val = subst_result.data; + goto store_val; #endif - /* Just pressing in shell should check for jobs. - * OTOH, in non-interactive shell this is useless - * and only leads to extra job checks */ - if (pi->num_cmds == 0) { - if (G_interactive_fd) - goto check_jobs_and_continue; - continue; - } +#if ENABLE_SH_MATH_SUPPORT + case '+': { /* +cmd */ + arith_t res; + int errcode; - /* After analyzing all keywords and conditions, we decided - * to execute this pipe. NB: have to do checkjobs(NULL) - * after run_pipe to collect any background children, - * even if list execution is to be stopped. */ - debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds); - { - int r; -#if ENABLE_HUSH_LOOPS - G.flag_break_continue = 0; -#endif - rcode = r = run_pipe(pi); /* NB: rcode is a smallint */ - if (r != -1) { - /* We ran a builtin, function, or group. - * rcode is already known - * and we don't need to wait for anything. */ - G.last_exitcode = rcode; - debug_printf_exec(": builtin/func exitcode %d\n", rcode); - check_and_run_traps(0); -#if ENABLE_HUSH_LOOPS - /* Was it "break" or "continue"? */ - if (G.flag_break_continue) { - smallint fbc = G.flag_break_continue; - /* We might fall into outer *loop*, - * don't want to break it too */ - if (loop_top) { - G.depth_break_continue--; - if (G.depth_break_continue == 0) - G.flag_break_continue = 0; - /* else: e.g. "continue 2" should *break* once, *then* continue */ - } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */ - if (G.depth_break_continue != 0 || fbc == BC_BREAK) - goto check_jobs_and_break; - /* "continue": simulate end of loop */ - rword = RES_DONE; - continue; - } -#endif -#if ENABLE_HUSH_FUNCTIONS - if (G.flag_return_in_progress == 1) { - /* same as "goto check_jobs_and_break" */ - checkjobs(NULL); + arg++; /* skip '+' */ + *p = '\0'; /* replace trailing */ + debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch); + res = expand_and_evaluate_arith(arg, &errcode); + + if (errcode < 0) { + const char *msg = "error in arithmetic"; + switch (errcode) { + case -3: + msg = "exponent less than 0"; + break; + case -2: + msg = "divide by 0"; + break; + case -5: + msg = "expression recursion loop detected"; break; } -#endif - } else if (pi->followup == PIPE_BG) { - /* What does bash do with attempts to background builtins? */ - /* even bash 3.2 doesn't do that well with nested bg: - * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". - * I'm NOT treating inner &'s as jobs */ - check_and_run_traps(0); -#if ENABLE_HUSH_JOB - if (G.run_list_level == 1) - insert_bg_job(pi); -#endif - /* Last command's pid goes to $! */ - G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid; - G.last_exitcode = rcode = EXIT_SUCCESS; - debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n"); - } else { -#if ENABLE_HUSH_JOB - if (G.run_list_level == 1 && G_interactive_fd) { - /* Waits for completion, then fg's main shell */ - rcode = checkjobs_and_fg_shell(pi); - debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode); - check_and_run_traps(0); - } else -#endif - { /* This one just waits for completion */ - rcode = checkjobs(pi); - debug_printf_exec(": checkjobs exitcode %d\n", rcode); - check_and_run_traps(0); - } - G.last_exitcode = rcode; + die_if_script(msg); } + debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res); + sprintf(arith_buf, arith_t_fmt, res); + val = arith_buf; + break; } - - /* Analyze how result affects subsequent commands */ -#if ENABLE_HUSH_IF - if (rword == RES_IF || rword == RES_ELIF) - cond_code = rcode; #endif -#if ENABLE_HUSH_LOOPS - /* Beware of "while false; true; do ..."! */ - if (pi->next && pi->next->res_word == RES_DO) { - if (rword == RES_WHILE) { - if (rcode) { - /* "while false; do...done" - exitcode 0 */ - G.last_exitcode = rcode = EXIT_SUCCESS; - debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n"); - goto check_jobs_and_break; - } - } - if (rword == RES_UNTIL) { - if (!rcode) { - debug_printf_exec(": until expr is true: breaking\n"); - check_jobs_and_break: - checkjobs(NULL); - break; + default: + val = expand_one_var(&to_be_freed, arg, &p, first_ch); + IF_HUSH_TICK(store_val:) + if (!(first_ch & 0x80)) { /* unquoted $VAR */ + debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape); + if (val && val[0]) { + /* unquoted var's contents should be globbed, so don't escape */ + smallint sv = output->o_escape; + output->o_escape = 0; + n = expand_on_ifs(output, n, val); + val = NULL; + output->o_escape = sv; } + } else { /* quoted $VAR, val will be appended below */ + debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape); } + break; + + } /* switch (char after ) */ + + if (val && val[0]) { + o_addQstr(output, val); } + free(to_be_freed); + /* Do the check to avoid writing to a const string */ + if (*p != SPECIAL_VAR_SYMBOL) + *p = SPECIAL_VAR_SYMBOL; + +#if ENABLE_HUSH_TICK + o_free(&subst_result); #endif + arg = ++p; + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ - check_jobs_and_continue: - checkjobs(NULL); - } /* for (pi) */ + if (arg[0]) { + debug_print_list("expand_vars_to_list[a]", output, n); + /* this part is literal, and it was already pre-quoted + * if needed (much earlier), do not use o_addQstr here! */ + o_addstr_with_NUL(output, arg); + debug_print_list("expand_vars_to_list[b]", output, n); + } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ + && !(ored_ch & 0x80) /* and all vars were not quoted. */ + ) { + n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; + } else { + o_addchr(output, '\0'); + } -#if ENABLE_HUSH_JOB - G.run_list_level--; -#endif -#if ENABLE_HUSH_LOOPS - if (loop_top) - G.depth_of_loop--; - free(for_list); -#endif -#if ENABLE_HUSH_CASE - free(case_word); + return n; +} + +enum { + EXPVAR_FLAG_GLOB = 0x200, + EXPVAR_FLAG_ESCAPE_VARS = 0x100, + EXPVAR_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */ +}; +static char **expand_variables(char **argv, unsigned or_mask) +{ + int n; + char **list; + char **v; + o_string output = NULL_O_STRING; + + /* protect against globbing for "$var"? */ + /* (unquoted $var will temporarily switch it off) */ + output.o_escape = 1 & (or_mask / EXPVAR_FLAG_ESCAPE_VARS); + output.o_glob = 1 & (or_mask / EXPVAR_FLAG_GLOB); + + n = 0; + v = argv; + while (*v) { + n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask); + v++; + } + debug_print_list("expand_variables", &output, n); + + /* output.data (malloced in one block) gets returned in "list" */ + list = o_finalize_list(&output, n); + debug_print_strings("expand_variables[1]", list); + return list; +} + +static char **expand_strvec_to_strvec(char **argv) +{ + return expand_variables(argv, EXPVAR_FLAG_GLOB | EXPVAR_FLAG_ESCAPE_VARS); +} + +#if ENABLE_HUSH_BASH_COMPAT +static char **expand_strvec_to_strvec_singleword_noglob(char **argv) +{ + return expand_variables(argv, EXPVAR_FLAG_SINGLEWORD); +} #endif - debug_leave(); - debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode); - return rcode; + +#ifdef CMD_SINGLEWORD_NOGLOB_COND +static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv) +{ + int n; + char **list; + char **v; + o_string output = NULL_O_STRING; + + n = 0; + v = argv; + while (*v) { + int is_var = is_well_formed_var_name(*v, '='); + /* is_var * 0x80: singleword expansion for vars */ + n = expand_vars_to_list(&output, n, *v, is_var * 0x80); + + /* Subtle! expand_vars_to_list did not glob last word yet. + * It does this only when fed with further data. + * Therefore we set globbing flags AFTER it, not before: + */ + + /* if it is not recognizably abc=...; then: */ + output.o_escape = !is_var; /* protect against globbing for "$var" */ + /* (unquoted $var will temporarily switch it off) */ + output.o_glob = !is_var; /* and indeed do globbing */ + v++; + } + debug_print_list("expand_cond", &output, n); + + /* output.data (malloced in one block) gets returned in "list" */ + list = o_finalize_list(&output, n); + debug_print_strings("expand_cond[1]", list); + return list; } +#endif -/* Select which version we will use */ -static int run_and_free_list(struct pipe *pi) +/* Used for expansion of right hand of assignments */ +/* NB: should NOT do globbing! + * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*" */ +static char *expand_string_to_string(const char *str) { - int rcode = 0; - debug_printf_exec("run_and_free_list entered\n"); - if (!G.n_mode) { - debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds); - rcode = run_list(pi); + char *argv[2], **list; + + /* This is generally an optimization, but it also + * handles "", which otherwise trips over !list[0] check below. + * (is this ever happens that we actually get str="" here?) + */ + if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) { + //TODO: Can use on strings with \ too, just unbackslash() them? + debug_printf_expand("string_to_string(fast)='%s'\n", str); + return xstrdup(str); } - /* free_pipe_list has the side effect of clearing memory. - * In the long run that function can be merged with run_list, - * but doing that now would hobble the debugging effort. */ - free_pipe_list(pi); - debug_printf_exec("run_and_free_list return %d\n", rcode); - return rcode; + + argv[0] = (char*)str; + argv[1] = NULL; + list = expand_variables(argv, EXPVAR_FLAG_ESCAPE_VARS | EXPVAR_FLAG_SINGLEWORD); + if (HUSH_DEBUG) + if (!list[0] || list[1]) + bb_error_msg_and_die("BUG in varexp2"); + /* actually, just move string 2*sizeof(char*) bytes back */ + overlapping_strcpy((char*)list, list[0]); + unbackslash((char*)list); + debug_printf_expand("string_to_string='%s'\n", (char*)list); + return (char*)list; } +/* Used for "eval" builtin */ +static char* expand_strvec_to_string(char **argv) +{ + char **list; -static struct pipe *new_pipe(void) + list = expand_variables(argv, EXPVAR_FLAG_SINGLEWORD); + /* Convert all NULs to spaces */ + if (list[0]) { + int n = 1; + while (list[n]) { + if (HUSH_DEBUG) + if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) + bb_error_msg_and_die("BUG in varexp3"); + /* bash uses ' ' regardless of $IFS contents */ + list[n][-1] = ' '; + n++; + } + } + overlapping_strcpy((char*)list, list[0]); + debug_printf_expand("strvec_to_string='%s'\n", (char*)list); + return (char*)list; +} + +static char **expand_assignments(char **argv, int count) { - struct pipe *pi; - pi = xzalloc(sizeof(struct pipe)); - /*pi->followup = 0; - deliberately invalid value */ - /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */ - return pi; + int i; + char **p; + + G.expanded_assignments = p = NULL; + /* Expand assignments into one string each */ + for (i = 0; i < count; i++) { + G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i])); + } + G.expanded_assignments = NULL; + return p; } -/* Command (member of a pipe) is complete, or we start a new pipe - * if ctx->command is NULL. - * No errors possible here. - */ -static int done_command(struct parse_context *ctx) + +#if BB_MMU +/* never called */ +void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; + +static void reset_traps_to_defaults(void) { - /* The command is really already in the pipe structure, so - * advance the pipe counter and make a new, null command. */ - struct pipe *pi = ctx->pipe; - struct command *command = ctx->command; + /* This function is always called in a child shell + * after fork (not vfork, NOMMU doesn't use this function). + */ + unsigned sig; + unsigned mask; - if (command) { - if (IS_NULL_CMD(command)) { - debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); - goto clear_and_ret; + /* Child shells are not interactive. + * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. + * Testcase: (while :; do :; done) + ^Z should background. + * Same goes for SIGTERM, SIGHUP, SIGINT. + */ + if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS)) + return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */ + + /* Switching off SPECIAL_INTERACTIVE_SIGS. + * Stupid. It can be done with *single* &= op, but we can't use + * the fact that G.blocked_set is implemented as a bitmask + * in libc... */ + mask = (SPECIAL_INTERACTIVE_SIGS >> 1); + sig = 1; + while (1) { + if (mask & 1) { + /* Careful. Only if no trap or trap is not "" */ + if (!G.traps || !G.traps[sig] || G.traps[sig][0]) + sigdelset(&G.blocked_set, sig); } - pi->num_cmds++; - debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); - //debug_print_tree(ctx->list_head, 20); - } else { - debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); + mask >>= 1; + if (!mask) + break; + sig++; } + /* Our homegrown sig mask is saner to work with :) */ + G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS; - /* Only real trickiness here is that the uncommitted - * command structure is not counted in pi->num_cmds. */ - pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1)); - ctx->command = command = &pi->cmds[pi->num_cmds]; - clear_and_ret: - memset(command, 0, sizeof(*command)); - return pi->num_cmds; /* used only for 0/nonzero check */ + /* Resetting all traps to default except empty ones */ + mask = G.non_DFL_mask; + if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) { + if (!G.traps[sig] || !G.traps[sig][0]) + continue; + free(G.traps[sig]); + G.traps[sig] = NULL; + /* There is no signal for 0 (EXIT) */ + if (sig == 0) + continue; + /* There was a trap handler, we just removed it. + * But if sig still has non-DFL handling, + * we should not unblock the sig. */ + if (mask & 1) + continue; + sigdelset(&G.blocked_set, sig); + } + sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); } -static void done_pipe(struct parse_context *ctx, pipe_style type) +#else /* !BB_MMU */ + +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) { - int not_null; +# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x")) + /* delims + 2 * (number of bytes in printed hex numbers) */ + char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)]; + char *heredoc_argv[4]; + struct variable *cur; +# if ENABLE_HUSH_FUNCTIONS + struct function *funcp; +# endif + char **argv, **pp; + unsigned cnt; + unsigned long long empty_trap_mask; - debug_printf_parse("done_pipe entered, followup %d\n", type); - /* Close previous command */ - not_null = done_command(ctx); - ctx->pipe->followup = type; -#if HAS_KEYWORDS - ctx->pipe->pi_inverted = ctx->ctx_inverted; - ctx->ctx_inverted = 0; - ctx->pipe->res_word = ctx->ctx_res_w; -#endif + if (!g_argv0) { /* heredoc */ + argv = heredoc_argv; + argv[0] = (char *) G.argv0_for_re_execing; + argv[1] = (char *) "-<"; + argv[2] = (char *) s; + argv[3] = NULL; + pp = &argv[3]; /* used as pointer to empty environment */ + goto do_exec; + } - /* Without this check, even just on command line generates - * tree of three NOPs (!). Which is harmless but annoying. - * IOW: it is safe to do it unconditionally. */ - if (not_null -#if ENABLE_HUSH_IF - || ctx->ctx_res_w == RES_FI -#endif -#if ENABLE_HUSH_LOOPS - || ctx->ctx_res_w == RES_DONE - || ctx->ctx_res_w == RES_FOR - || ctx->ctx_res_w == RES_IN -#endif -#if ENABLE_HUSH_CASE - || ctx->ctx_res_w == RES_ESAC -#endif - ) { - struct pipe *new_p; - debug_printf_parse("done_pipe: adding new pipe: " - "not_null:%d ctx->ctx_res_w:%d\n", - not_null, ctx->ctx_res_w); - new_p = new_pipe(); - ctx->pipe->next = new_p; - ctx->pipe = new_p; - /* RES_THEN, RES_DO etc are "sticky" - - * they remain set for pipes inside if/while. - * This is used to control execution. - * RES_FOR and RES_IN are NOT sticky (needed to support - * cases where variable or value happens to match a keyword): - */ -#if ENABLE_HUSH_LOOPS - if (ctx->ctx_res_w == RES_FOR - || ctx->ctx_res_w == RES_IN) - ctx->ctx_res_w = RES_NONE; -#endif -#if ENABLE_HUSH_CASE - if (ctx->ctx_res_w == RES_MATCH) - ctx->ctx_res_w = RES_CASE_BODY; - if (ctx->ctx_res_w == RES_CASE) - ctx->ctx_res_w = RES_CASE_IN; -#endif - ctx->command = NULL; /* trick done_command below */ - /* Create the memory for command, roughly: - * ctx->pipe->cmds = new struct command; - * ctx->command = &ctx->pipe->cmds[0]; - */ - done_command(ctx); - //debug_print_tree(ctx->list_head, 10); + cnt = 0; + pp = builtin_argv; + if (pp) while (*pp++) + cnt++; + + empty_trap_mask = 0; + if (G.traps) { + int sig; + for (sig = 1; sig < NSIG; sig++) { + if (G.traps[sig] && !G.traps[sig][0]) + empty_trap_mask |= 1LL << sig; + } } - debug_printf_parse("done_pipe return\n"); -} -static void initialize_context(struct parse_context *ctx) -{ - memset(ctx, 0, sizeof(*ctx)); - ctx->pipe = ctx->list_head = new_pipe(); - /* Create the memory for command, roughly: - * ctx->pipe->cmds = new struct command; - * ctx->command = &ctx->pipe->cmds[0]; + sprintf(param_buf, NOMMU_HACK_FMT + , (unsigned) G.root_pid + , (unsigned) G.root_ppid + , (unsigned) G.last_bg_pid + , (unsigned) G.last_exitcode + , cnt + , empty_trap_mask + IF_HUSH_LOOPS(, G.depth_of_loop) + ); +# undef NOMMU_HACK_FMT + /* 1:hush 2:-$::: + * 3:-c 4: 5: 6:NULL */ - done_command(ctx); + cnt += 6; + for (cur = G.top_var; cur; cur = cur->next) { + if (!cur->flg_export || cur->flg_read_only) + cnt += 2; + } +# if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) + cnt += 3; +# endif + pp = g_argv; + while (*pp++) + cnt++; + *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt); + *pp++ = (char *) G.argv0_for_re_execing; + *pp++ = param_buf; + for (cur = G.top_var; cur; cur = cur->next) { + if (strcmp(cur->varstr, hush_version_str) == 0) + continue; + if (cur->flg_read_only) { + *pp++ = (char *) "-R"; + *pp++ = cur->varstr; + } else if (!cur->flg_export) { + *pp++ = (char *) "-V"; + *pp++ = cur->varstr; + } + } +# if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) { + *pp++ = (char *) "-F"; + *pp++ = funcp->name; + *pp++ = funcp->body_as_string; + } +# endif + /* We can pass activated traps here. Say, -Tnn:trap_string + * + * However, POSIX says that subshells reset signals with traps + * to SIG_DFL. + * I tested bash-3.2 and it not only does that with true subshells + * of the form ( list ), but with any forked children shells. + * I set trap "echo W" WINCH; and then tried: + * + * { echo 1; sleep 20; echo 2; } & + * while true; do echo 1; sleep 20; echo 2; break; done & + * true | { echo 1; sleep 20; echo 2; } | cat + * + * In all these cases sending SIGWINCH to the child shell + * did not run the trap. If I add trap "echo V" WINCH; + * _inside_ group (just before echo 1), it works. + * + * I conclude it means we don't need to pass active traps here. + * Even if we would use signal handlers instead of signal masking + * in order to implement trap handling, + * exec syscall below resets signals to SIG_DFL for us. + */ + *pp++ = (char *) "-c"; + *pp++ = (char *) s; + if (builtin_argv) { + while (*++builtin_argv) + *pp++ = *builtin_argv; + *pp++ = (char *) ""; + } + *pp++ = g_argv0; + while (*g_argv) + *pp++ = *g_argv++; + /* *pp = NULL; - is already there */ + pp = environ; + + do_exec: + debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s); + sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); + execve(bb_busybox_exec_path, argv, pp); + /* Fallback. Useful for init=/bin/hush usage etc */ + if (argv[0][0] == '/') + execve(argv[0], argv, pp); + xfunc_error_retval = 127; + bb_error_msg_and_die("can't re-execute the shell"); } +#endif /* !BB_MMU */ -/* If a reserved word is found and processed, parse context is modified - * and 1 is returned. - */ -#if HAS_KEYWORDS -struct reserved_combo { - char literal[6]; - unsigned char res; - unsigned char assignment_flag; - int flag; -}; -enum { - FLAG_END = (1 << RES_NONE ), -# if ENABLE_HUSH_IF - FLAG_IF = (1 << RES_IF ), - FLAG_THEN = (1 << RES_THEN ), - FLAG_ELIF = (1 << RES_ELIF ), - FLAG_ELSE = (1 << RES_ELSE ), - FLAG_FI = (1 << RES_FI ), -# endif -# if ENABLE_HUSH_LOOPS - FLAG_FOR = (1 << RES_FOR ), - FLAG_WHILE = (1 << RES_WHILE), - FLAG_UNTIL = (1 << RES_UNTIL), - FLAG_DO = (1 << RES_DO ), - FLAG_DONE = (1 << RES_DONE ), - FLAG_IN = (1 << RES_IN ), -# endif -# if ENABLE_HUSH_CASE - FLAG_MATCH = (1 << RES_MATCH), - FLAG_ESAC = (1 << RES_ESAC ), -# endif - FLAG_START = (1 << RES_XXXX ), -}; -static const struct reserved_combo* match_reserved_word(o_string *word) -{ - /* Mostly a list of accepted follow-up reserved words. - * FLAG_END means we are done with the sequence, and are ready - * to turn the compound list into a command. - * FLAG_START means the word must start a new compound list. - */ - static const struct reserved_combo reserved_list[] = { -# if ENABLE_HUSH_IF - { "!", RES_NONE, NOT_ASSIGNMENT , 0 }, - { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START }, - { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, - { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN }, - { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI }, - { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END }, -# endif -# if ENABLE_HUSH_LOOPS - { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START }, - { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, - { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, - { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO }, - { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE }, - { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END }, -# endif -# if ENABLE_HUSH_CASE - { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START }, - { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END }, -# endif - }; - const struct reserved_combo *r; +static int run_and_free_list(struct pipe *pi); - for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { - if (strcmp(word->data, r->literal) == 0) - return r; - } - return NULL; -} -/* Return 0: not a keyword, 1: keyword +/* Executing from string: eval, sh -c '...' + * or from file: /etc/profile, . file, sh