diff options
Diffstat (limited to 'shell')
| -rw-r--r-- | shell/hush.c | 1848 |
1 files changed, 904 insertions, 944 deletions
diff --git a/shell/hush.c b/shell/hush.c index 9c0cd7c..0e43b63 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -1,9 +1,9 @@ /* vi: set sw=4 ts=4: */ /* - * sh.c -- a prototype Bourne shell grammar parser - * Intended to follow the original Thompson and Ritchie - * "small and simple is beautiful" philosophy, which - * incidentally is a good match to today's BusyBox. + * A prototype Bourne shell grammar parser. + * Intended to follow the original Thompson and Ritchie + * "small and simple is beautiful" philosophy, which + * incidentally is a good match to today's BusyBox. * * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> * @@ -22,8 +22,8 @@ * Other credits: * o_addchr() derived from similar w_addchar function in glibc-2.2. * setup_redirect(), redirect_opt_num(), and big chunks of main() - * and many builtins derived from contributions by Erik Andersen - * miscellaneous bugfixes from Matt Kraai. + * and many builtins derived from contributions by Erik Andersen. + * Miscellaneous bugfixes from Matt Kraai. * * There are two big (and related) architecture differences between * this parser and the lash parser. One is that this version is @@ -55,19 +55,17 @@ * change { and } from special chars to reserved words * builtins: return, trap, ulimit * test magic exec with redirection only - * check setting of global_argc and global_argv * follow IFS rules more precisely, including update semantics * figure out what to do with backslash-newline * propagate syntax errors, die on resource errors? * continuation lines, both explicit and implicit - done? - * memory leak finding and plugging - done? * maybe change charmap[] to use 2-bit entries * * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */ -//TODO: pull in some .h and find out do we have SINGLE_APPLET_MAIN? +//TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN? //#include "applet_tables.h" doesn't work #include <glob.h> /* #include <dmalloc.h> */ @@ -75,7 +73,7 @@ #include <fnmatch.h> #endif -#define HUSH_VER_STR "0.91" +#define HUSH_VER_STR "0.92" #if defined SINGLE_APPLET_MAIN /* STANDALONE does not make sense, and won't compile */ @@ -108,6 +106,16 @@ #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 #endif +/* Do we support ANY keywords? */ +#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE +#define HAS_KEYWORDS 1 +#define IF_HAS_KEYWORDS(...) __VA_ARGS__ +#define IF_HAS_NO_KEYWORDS(...) +#else +#define HAS_KEYWORDS 0 +#define IF_HAS_KEYWORDS(...) +#define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__ +#endif /* Keep unconditionally on for now */ #define HUSH_DEBUG 1 @@ -237,17 +245,9 @@ void xxfree(void *ptr) #endif -/* Do we support ANY keywords? */ -#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE -#define HAS_KEYWORDS 1 -#define IF_HAS_KEYWORDS(...) __VA_ARGS__ -#define IF_HAS_NO_KEYWORDS(...) -#else -#define HAS_KEYWORDS 0 -#define IF_HAS_KEYWORDS(...) -#define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__ -#endif +static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR; +#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" #define SPECIAL_VAR_SYMBOL 3 #define PARSEFLAG_EXIT_FROM_LOOP 1 @@ -324,7 +324,7 @@ struct command { pid_t pid; /* 0 if exited */ int assignment_cnt; /* how many argv[i] are assignments? */ smallint is_stopped; /* is the command currently running? */ - smallint grp_type; + smallint grp_type; /* GRP_xxx */ struct pipe *group; /* if non-NULL, this "prog" is {} group, * subshell, or a compound statement */ char **argv; /* command name and arguments */ @@ -442,7 +442,6 @@ enum { /* "Globals" within this file */ - /* Sorted roughly by size (smaller offsets == smaller code) */ struct globals { #if ENABLE_HUSH_INTERACTIVE @@ -503,7 +502,93 @@ struct globals { } while (0) -#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" +/* Function prototypes for builtins */ +static int builtin_cd(char **argv); +static int builtin_echo(char **argv); +static int builtin_eval(char **argv); +static int builtin_exec(char **argv); +static int builtin_exit(char **argv); +static int builtin_export(char **argv); +#if ENABLE_HUSH_JOB +static int builtin_fg_bg(char **argv); +static int builtin_jobs(char **argv); +#endif +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv); +#endif +static int builtin_pwd(char **argv); +static int builtin_read(char **argv); +static int builtin_test(char **argv); +static int builtin_true(char **argv); +static int builtin_set(char **argv); +static int builtin_shift(char **argv); +static int builtin_source(char **argv); +static int builtin_umask(char **argv); +static int builtin_unset(char **argv); +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv); +static int builtin_continue(char **argv); +#endif +//static int builtin_not_written(char **argv); + +/* Table of built-in functions. They can be forked or not, depending on + * context: within pipes, they fork. As simple commands, they do not. + * When used in non-forking context, they can change global variables + * in the parent shell process. If forked, of course they cannot. + * For example, 'unset foo | whatever' will parse and run, but foo will + * still be set at the end. */ +struct built_in_command { + const char *cmd; + int (*function)(char **argv); +#if ENABLE_HUSH_HELP + const char *descr; +#define BLTIN(cmd, func, help) { cmd, func, help } +#else +#define BLTIN(cmd, func, help) { cmd, func } +#endif +}; + +/* For now, echo and test are unconditionally enabled. + * Maybe make it configurable? */ +static const struct built_in_command bltins[] = { + BLTIN("." , builtin_source, "Run commands in a file"), + BLTIN(":" , builtin_true, "No-op"), + BLTIN("[" , builtin_test, "Test condition"), + BLTIN("[[" , builtin_test, "Test condition"), +#if ENABLE_HUSH_JOB + BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"), +#endif +#if ENABLE_HUSH_LOOPS + BLTIN("break" , builtin_break, "Exit from a loop"), +#endif + BLTIN("cd" , builtin_cd, "Change directory"), +#if ENABLE_HUSH_LOOPS + BLTIN("continue", builtin_continue, "Start new loop iteration"), +#endif + BLTIN("echo" , builtin_echo, "Write to stdout"), + BLTIN("eval" , builtin_eval, "Construct and run shell command"), + BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"), + BLTIN("exit" , builtin_exit, "Exit"), + BLTIN("export", builtin_export, "Set environment variable"), +#if ENABLE_HUSH_JOB + BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"), + BLTIN("jobs" , builtin_jobs, "List active jobs"), +#endif + BLTIN("pwd" , builtin_pwd, "Print current directory"), + BLTIN("read" , builtin_read, "Input environment variable"), +// BLTIN("return", builtin_not_written, "Return from a function"), + BLTIN("set" , builtin_set, "Set/unset shell local variables"), + BLTIN("shift" , builtin_shift, "Shift positional parameters"), +// BLTIN("trap" , builtin_not_written, "Trap signals"), + BLTIN("test" , builtin_test, "Test condition"), +// BLTIN("ulimit", builtin_not_written, "Control resource limits"), + BLTIN("umask" , builtin_umask, "Set file creation mask"), + BLTIN("unset" , builtin_unset, "Unset environment variable"), +#if ENABLE_HUSH_HELP + BLTIN("help" , builtin_help, "List shell built-in commands"), +#endif +}; + #if 1 /* Normal */ @@ -520,7 +605,6 @@ static void syntax(const char *msg) bb_error_msg_and_die(msg ? "%s: %s" : "syntax error", "syntax error", msg); #endif } - #else /* Debug */ static void syntax_lineno(int line) @@ -536,84 +620,6 @@ static void syntax_lineno(int line) #define syntax(str) syntax_lineno(__LINE__) #endif -/* Index of subroutines: */ -/* in_str manipulations: */ -static int static_get(struct in_str *i); -static int static_peek(struct in_str *i); -static int file_get(struct in_str *i); -static int file_peek(struct in_str *i); -static void setup_file_in_str(struct in_str *i, FILE *f); -static void setup_string_in_str(struct in_str *i, const char *s); -/* "run" the final data structures: */ -#if !defined(DEBUG_CLEAN) -#define free_pipe_list(head, indent) free_pipe_list(head) -#define free_pipe(pi, indent) free_pipe(pi) -#endif -static int free_pipe_list(struct pipe *head, int indent); -static int free_pipe(struct pipe *pi, int indent); -/* really run the final data structures: */ -typedef struct nommu_save_t { - char **new_env; - char **old_env; - char **argv; -} nommu_save_t; -#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 -static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN; -static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN; -static int setup_redirects(struct command *prog, int squirrel[]); -static int run_list(struct pipe *pi); -static int run_pipe(struct pipe *pi); -/* data structure manipulation: */ -static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, struct in_str *input); -static void initialize_context(struct parse_context *ctx); -static int done_word(o_string *dest, struct parse_context *ctx); -static int done_command(struct parse_context *ctx); -static void done_pipe(struct parse_context *ctx, pipe_style type); -/* primary string parsing: */ -static int redirect_dup_num(struct in_str *input); -static int redirect_opt_num(o_string *o); -#if ENABLE_HUSH_TICK -static int process_command_subs(o_string *dest, - struct in_str *input, const char *subst_end); -#endif -static int parse_group(o_string *dest, struct parse_context *ctx, struct in_str *input, int ch); -static const char *lookup_param(const char *src); -static int handle_dollar(o_string *dest, - struct in_str *input); -static int parse_stream(o_string *dest, struct parse_context *ctx, struct in_str *input0, const char *end_trigger); -/* setup: */ -static int parse_and_run_stream(struct in_str *inp, int parse_flag); -static int parse_and_run_string(const char *s, int parse_flag); -static int parse_and_run_file(FILE *f); -/* job management: */ -static int checkjobs(struct pipe* fg_pipe); -#if ENABLE_HUSH_JOB -static int checkjobs_and_fg_shell(struct pipe* fg_pipe); -static void insert_bg_job(struct pipe *pi); -static void remove_bg_job(struct pipe *pi); -static void delete_finished_bg_job(struct pipe *pi); -#else -int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */ -#endif -/* local variable support */ -static char **expand_strvec_to_strvec(char **argv); -/* used for eval */ -static char *expand_strvec_to_string(char **argv); -/* used for expansion of right hand of assignments */ -static char *expand_string_to_string(const char *str); -static struct variable *get_local_var(const char *name); -static int set_local_var(char *str, int flg_export); -static void unset_local_var(const char *name); - - -static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR; - - static int glob_needed(const char *s) { while (*s) { @@ -747,94 +753,6 @@ static void free_strings(char **strings) } -/* Function prototypes for builtins */ -static int builtin_cd(char **argv); -static int builtin_echo(char **argv); -static int builtin_eval(char **argv); -static int builtin_exec(char **argv); -static int builtin_exit(char **argv); -static int builtin_export(char **argv); -#if ENABLE_HUSH_JOB -static int builtin_fg_bg(char **argv); -static int builtin_jobs(char **argv); -#endif -#if ENABLE_HUSH_HELP -static int builtin_help(char **argv); -#endif -static int builtin_pwd(char **argv); -static int builtin_read(char **argv); -static int builtin_test(char **argv); -static int builtin_true(char **argv); -static int builtin_set(char **argv); -static int builtin_shift(char **argv); -static int builtin_source(char **argv); -static int builtin_umask(char **argv); -static int builtin_unset(char **argv); -#if ENABLE_HUSH_LOOPS -static int builtin_break(char **argv); -static int builtin_continue(char **argv); -#endif -//static int builtin_not_written(char **argv); - -/* Table of built-in functions. They can be forked or not, depending on - * context: within pipes, they fork. As simple commands, they do not. - * When used in non-forking context, they can change global variables - * in the parent shell process. If forked, of course they cannot. - * For example, 'unset foo | whatever' will parse and run, but foo will - * still be set at the end. */ -struct built_in_command { - const char *cmd; - int (*function)(char **argv); -#if ENABLE_HUSH_HELP - const char *descr; -#define BLTIN(cmd, func, help) { cmd, func, help } -#else -#define BLTIN(cmd, func, help) { cmd, func } -#endif -}; - -/* For now, echo and test are unconditionally enabled. - * Maybe make it configurable? */ -static const struct built_in_command bltins[] = { - BLTIN("." , builtin_source, "Run commands in a file"), - BLTIN(":" , builtin_true, "No-op"), - BLTIN("[" , builtin_test, "Test condition"), - BLTIN("[[" , builtin_test, "Test condition"), -#if ENABLE_HUSH_JOB - BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"), -#endif -#if ENABLE_HUSH_LOOPS - BLTIN("break" , builtin_break, "Exit from a loop"), -#endif - BLTIN("cd" , builtin_cd, "Change directory"), -#if ENABLE_HUSH_LOOPS - BLTIN("continue", builtin_continue, "Start new loop iteration"), -#endif - BLTIN("echo" , builtin_echo, "Write to stdout"), - BLTIN("eval" , builtin_eval, "Construct and run shell command"), - BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"), - BLTIN("exit" , builtin_exit, "Exit"), - BLTIN("export", builtin_export, "Set environment variable"), -#if ENABLE_HUSH_JOB - BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"), - BLTIN("jobs" , builtin_jobs, "List active jobs"), -#endif - BLTIN("pwd" , builtin_pwd, "Print current directory"), - BLTIN("read" , builtin_read, "Input environment variable"), -// BLTIN("return", builtin_not_written, "Return from a function"), - BLTIN("set" , builtin_set, "Set/unset shell local variables"), - BLTIN("shift" , builtin_shift, "Shift positional parameters"), -// BLTIN("trap" , builtin_not_written, "Trap signals"), - BLTIN("test" , builtin_test, "Test condition"), -// BLTIN("ulimit", builtin_not_written, "Control resource limits"), - BLTIN("umask" , builtin_umask, "Set file creation mask"), - BLTIN("unset" , builtin_unset, "Unset environment variable"), -#if ENABLE_HUSH_HELP - BLTIN("help" , builtin_help, "List shell built-in commands"), -#endif -}; - - /* Signals are grouped, we handle them in batches */ static void set_misc_sighandler(void (*handler)(int)) { @@ -961,8 +879,10 @@ static void hush_exit(int exitcode) static const char *set_cwd(void) { + /* xrealloc_getcwd_or_warn(arg) calls free(arg), + * we must not try to free(bb_msg_unknown) */ if (G.cwd == bb_msg_unknown) - G.cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */ + G.cwd = NULL; G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); if (!G.cwd) G.cwd = bb_msg_unknown; @@ -970,6 +890,295 @@ static const char *set_cwd(void) } +/* Get/check local shell variables */ +static struct variable *get_local_var(const char *name) +{ + struct variable *cur; + int len; + + if (!name) + return NULL; + len = strlen(name); + for (cur = G.top_var; cur; cur = cur->next) { + if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') + return cur; + } + return NULL; +} + +/* Basically useful version until someone wants to get fancier, + * see the bash man page under "Parameter Expansion" */ +static const char *lookup_param(const char *src) +{ + struct variable *var = get_local_var(src); + if (var) + return strchr(var->varstr, '=') + 1; + return NULL; +} + +/* str holds "NAME=VAL" and is expected to be malloced. + * We take ownership of it. */ +static int set_local_var(char *str, int flg_export) +{ + struct variable *cur; + char *value; + int name_len; + + value = strchr(str, '='); + if (!value) { /* not expected to ever happen? */ + free(str); + return -1; + } + + name_len = value - str + 1; /* including '=' */ + cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ + while (1) { + if (strncmp(cur->varstr, str, name_len) != 0) { + if (!cur->next) { + /* Bail out. Note that now cur points + * to last var in linked list */ + break; + } + cur = cur->next; + continue; + } + /* We found an existing var with this name */ + *value = '\0'; + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", str); + free(str); + return -1; + } + debug_printf_env("%s: unsetenv '%s'\n", __func__, str); + unsetenv(str); /* just in case */ + *value = '='; + if (strcmp(cur->varstr, str) == 0) { + free_and_exp: + free(str); + goto exp; + } + if (cur->max_len >= strlen(str)) { + /* This one is from startup env, reuse space */ + strcpy(cur->varstr, str); + goto free_and_exp; + } + /* max_len == 0 signifies "malloced" var, which we can + * (and has to) free */ + if (!cur->max_len) + free(cur->varstr); + cur->max_len = 0; + goto set_str_and_exp; + } + + /* Not found - create next variable struct */ + cur->next = xzalloc(sizeof(*cur)); + cur = cur->next; + + set_str_and_exp: + cur->varstr = str; + exp: + if (flg_export) + cur->flg_export = 1; + if (cur->flg_export) { + debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr); + return putenv(cur->varstr); + } + return 0; +} + +static void unset_local_var(const char *name) +{ + struct variable *cur; + struct variable *prev = prev; /* for gcc */ + int name_len; + + if (!name) + return; + name_len = strlen(name); + cur = G.top_var; + while (cur) { + if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", name); + return; + } + /* prev is ok to use here because 1st variable, HUSH_VERSION, + * is ro, and we cannot reach this code on the 1st pass */ + prev->next = cur->next; + debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr); + bb_unsetenv(cur->varstr); + if (!cur->max_len) + free(cur->varstr); + free(cur); + return; + } + prev = cur; + cur = cur->next; + } +} + + +/* + * in_str support + */ +static int static_get(struct in_str *i) +{ + int ch = *i->p++; + if (ch == '\0') return EOF; + return ch; +} + +static int static_peek(struct in_str *i) +{ + return *i->p; +} + +#if ENABLE_HUSH_INTERACTIVE + +#if ENABLE_FEATURE_EDITING +static void cmdedit_set_initial_prompt(void) +{ +#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT + G.PS1 = NULL; +#else + G.PS1 = getenv("PS1"); + if (G.PS1 == NULL) + G.PS1 = "\\w \\$ "; +#endif +} +#endif /* EDITING */ + +static const char* setup_prompt_string(int promptmode) +{ + const char *prompt_str; + debug_printf("setup_prompt_string %d ", promptmode); +#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT + /* Set up the prompt */ + if (promptmode == 0) { /* PS1 */ + free((char*)G.PS1); + G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#'); + prompt_str = G.PS1; + } else { + prompt_str = G.PS2; + } +#else + prompt_str = (promptmode == 0) ? G.PS1 : G.PS2; +#endif + debug_printf("result '%s'\n", prompt_str); + return prompt_str; +} + +static void get_user_input(struct in_str *i) +{ + int r; + const char *prompt_str; + + prompt_str = setup_prompt_string(i->promptmode); +#if ENABLE_FEATURE_EDITING + /* Enable command line editing only while a command line + * is actually being read */ + do { + r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state); + } while (r == 0); /* repeat if Ctrl-C */ + i->eof_flag = (r < 0); + if (i->eof_flag) { /* EOF/error detected */ + G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ + G.user_input_buf[1] = '\0'; + } +#else + fputs(prompt_str, stdout); + fflush(stdout); + G.user_input_buf[0] = r = fgetc(i->file); + /*G.user_input_buf[1] = '\0'; - already is and never changed */ + i->eof_flag = (r == EOF); +#endif + i->p = G.user_input_buf; +} + +#endif /* INTERACTIVE */ + +/* This is the magic location that prints prompts + * and gets data back from the user */ +static int file_get(struct in_str *i) +{ + int ch; + + /* If there is data waiting, eat it up */ + if (i->p && *i->p) { +#if ENABLE_HUSH_INTERACTIVE + take_cached: +#endif + ch = *i->p++; + if (i->eof_flag && !*i->p) + ch = EOF; + } else { + /* need to double check i->file because we might be doing something + * more complicated by now, like sourcing or substituting. */ +#if ENABLE_HUSH_INTERACTIVE + if (G.interactive_fd && i->promptme && i->file == stdin) { + do { + get_user_input(i); + } while (!*i->p); /* need non-empty line */ + i->promptmode = 1; /* PS2 */ + i->promptme = 0; + goto take_cached; + } +#endif + ch = fgetc(i->file); + } + debug_printf("file_get: got a '%c' %d\n", ch, ch); +#if ENABLE_HUSH_INTERACTIVE + if (ch == '\n') + i->promptme = 1; +#endif + return ch; +} + +/* All the callers guarantee this routine will never be + * used right after a newline, so prompting is not needed. + */ +static int file_peek(struct in_str *i) +{ + int ch; + if (i->p && *i->p) { + if (i->eof_flag && !i->p[1]) + return EOF; + return *i->p; + } + ch = fgetc(i->file); + i->eof_flag = (ch == EOF); + i->peek_buf[0] = ch; + i->peek_buf[1] = '\0'; + i->p = i->peek_buf; + debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p); + return ch; +} + +static void setup_file_in_str(struct in_str *i, FILE *f) +{ + i->peek = file_peek; + i->get = file_get; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif + i->file = f; + i->p = NULL; +} + +static void setup_string_in_str(struct in_str *i, const char *s) +{ + i->peek = static_peek; + i->get = static_get; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif + i->p = s; + i->eof_flag = 0; +} + + /* * o_string support */ @@ -1252,164 +1461,300 @@ static char **o_finalize_list(o_string *o, int n) } -/* - * in_str support - */ -static int static_get(struct in_str *i) -{ - int ch = *i->p++; - if (ch == '\0') return EOF; - return ch; -} +/* 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 $VAR). + * This new list is allocated as a single malloc block. + * NULL-terminated list of char* pointers is at the beginning of it, + * followed by strings themself. + * Caller can deallocate entire list by single free(list). */ -static int static_peek(struct in_str *i) +/* Store given string, finalizing the word and starting new one whenever + * we encounter IFS char(s). This is used for expanding variable values. + * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ +static int expand_on_ifs(o_string *output, int n, const char *str) { - return *i->p; + while (1) { + int word_len = strcspn(str, G.ifs); + if (word_len) { + if (output->o_quote || !output->o_glob) + o_addQstr(output, str, word_len); + else /* protect backslashes against globbing up :) */ + o_addstr_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; } -#if ENABLE_HUSH_INTERACTIVE +#if ENABLE_HUSH_TICK +static int process_command_subs(o_string *dest, + struct in_str *input, const char *subst_end); +#endif -#if ENABLE_FEATURE_EDITING -static void cmdedit_set_initial_prompt(void) +/* 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 int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) { -#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT - G.PS1 = NULL; -#else - G.PS1 = getenv("PS1"); - if (G.PS1 == NULL) - G.PS1 = "\\w \\$ "; + /* 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 first_ch, ored_ch; + int i; + const char *val; + char *p; + + ored_ch = 0; + + debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); + 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) { +#if ENABLE_HUSH_TICK + o_string subst_result = NULL_O_STRING; #endif -} -#endif /* EDITING */ + o_addstr(output, arg, p - arg); + debug_print_list("expand_vars_to_list[1]", output, n); + arg = ++p; + p = strchr(p, SPECIAL_VAR_SYMBOL); -static const char* setup_prompt_string(int promptmode) -{ - const char *prompt_str; - debug_printf("setup_prompt_string %d ", promptmode); -#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT - /* Set up the prompt */ - if (promptmode == 0) { /* PS1 */ - free((char*)G.PS1); - G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#'); - prompt_str = G.PS1; + first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ + /* "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string) */ + if ((first_ch & 0x7f) != '@') + ored_ch |= first_ch; + val = NULL; + switch (first_ch & 0x7f) { + /* Highest bit in first_ch indicates that var is double-quoted */ + case '$': /* pid */ + val = utoa(G.root_pid); + break; + case '!': /* bg pid */ + val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)""; + break; + case '?': /* exitcode */ + val = utoa(G.last_return_code); + break; + case '#': /* argc */ + val = utoa(G.global_argc ? G.global_argc-1 : 0); + break; + case '*': + case '@': + i = 1; + if (!G.global_argv[i]) + break; + ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ + if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ + smallint sv = output->o_quote; + /* unquoted var's contents should be globbed, so don't quote */ + output->o_quote = 0; + while (G.global_argv[i]) { + n = expand_on_ifs(output, n, G.global_argv[i]); + debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); + if (G.global_argv[i++][0] && G.global_argv[i]) { + /* this argv[] is not empty and not last: + * put terminating NUL, start new word */ + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[2]", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[3]", output, n); + } + } + output->o_quote = sv; + } else + /* If or_mask is nonzero, we handle assignment 'a=....$@.....' + * 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], strlen(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], strlen(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: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */ + /* "Empty variable", used to make "" etc to not disappear */ + arg++; + ored_ch = 0x80; + break; +#if ENABLE_HUSH_TICK + case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ + struct in_str input; + *p = '\0'; + arg++; +//TODO: can we just stuff it into "output" directly? + debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); + setup_string_in_str(&input, arg); + process_command_subs(&subst_result, &input, NULL); + debug_printf_subst("SUBST RES '%s'\n", subst_result.data); + val = subst_result.data; + goto store_val; + } +#endif + default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */ + *p = '\0'; + arg[0] = first_ch & 0x7f; + if (isdigit(arg[0])) { + i = xatoi_u(arg); + if (i < G.global_argc) + val = G.global_argv[i]; + /* else val remains NULL: $N with too big N */ + } else + val = lookup_param(arg); + arg[0] = first_ch; +#if ENABLE_HUSH_TICK + store_val: +#endif + *p = SPECIAL_VAR_SYMBOL; + if (!(first_ch & 0x80)) { /* unquoted $VAR */ + debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote); + if (val) { + /* unquoted var's contents should be globbed, so don't quote */ + smallint sv = output->o_quote; + output->o_quote = 0; + n = expand_on_ifs(output, n, val); + val = NULL; + output->o_quote = sv; + } + } else { /* quoted $VAR, val will be appended below */ + debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote); + } + } + if (val) { + o_addQstr(output, val, strlen(val)); + } + +#if ENABLE_HUSH_TICK + o_free(&subst_result); +#endif + arg = ++p; + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ + + if (arg[0]) { + debug_print_list("expand_vars_to_list[a]", output, n); + /* this part is literal, and it was already pre-quoted + * if needed (much earlier), do not use o_addQstr here! */ + o_addstr(output, arg, strlen(arg) + 1); + debug_print_list("expand_vars_to_list[b]", output, n); + } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ + && !(ored_ch & 0x80) /* and all vars were not quoted. */ + ) { + n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; } else { - prompt_str = G.PS2; + o_addchr(output, '\0'); } -#else - prompt_str = (promptmode == 0) ? G.PS1 : G.PS2; -#endif - debug_printf("result '%s'\n", prompt_str); - return prompt_str; + return n; } -static void get_user_input(struct in_str *i) +static char **expand_variables(char **argv, int or_mask) { - int r; - const char *prompt_str; + int n; + char **list; + char **v; + o_string output = NULL_O_STRING; - prompt_str = setup_prompt_string(i->promptmode); -#if ENABLE_FEATURE_EDITING - /* Enable command line editing only while a command line - * is actually being read */ - do { - r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state); - } while (r == 0); /* repeat if Ctrl-C */ - i->eof_flag = (r < 0); - if (i->eof_flag) { /* EOF/error detected */ - G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ - G.user_input_buf[1] = '\0'; + if (or_mask & 0x100) { + output.o_quote = 1; /* protect against globbing for "$var" */ + /* (unquoted $var will temporarily switch it off) */ + output.o_glob = 1; } -#else - fputs(prompt_str, stdout); - fflush(stdout); - G.user_input_buf[0] = r = fgetc(i->file); - /*G.user_input_buf[1] = '\0'; - already is and never changed */ - i->eof_flag = (r == EOF); -#endif - i->p = G.user_input_buf; -} -#endif /* INTERACTIVE */ + n = 0; + v = argv; + while (*v) { + n = expand_vars_to_list(&output, n, *v, (char)or_mask); + v++; + } + debug_print_list("expand_variables", &output, n); -/* This is the magic location that prints prompts - * and gets data back from the user */ -static int file_get(struct in_str *i) -{ - int ch; + /* 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; +} - /* If there is data waiting, eat it up */ - if (i->p && *i->p) { -#if ENABLE_HUSH_INTERACTIVE - take_cached: -#endif - ch = *i->p++; - if (i->eof_flag && !*i->p) - ch = EOF; - } else { - /* need to double check i->file because we might be doing something - * more complicated by now, like sourcing or substituting. */ -#if ENABLE_HUSH_INTERACTIVE - if (G.interactive_fd && i->promptme && i->file == stdin) { - do { - get_user_input(i); - } while (!*i->p); /* need non-empty line */ - i->promptmode = 1; /* PS2 */ - i->promptme = 0; - goto take_cached; - } -#endif - ch = fgetc(i->file); - } - debug_printf("file_get: got a '%c' %d\n", ch, ch); -#if ENABLE_HUSH_INTERACTIVE - if (ch == '\n') - i->promptme = 1; -#endif - return ch; +static char **expand_strvec_to_strvec(char **argv) +{ + return expand_variables(argv, 0x100); } -/* All the callers guarantee this routine will never be - * used right after a newline, so prompting is not needed. - */ -static int file_peek(struct in_str *i) +/* 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 ch; - if (i->p && *i->p) { - if (i->eof_flag && !i->p[1]) - return EOF; - return *i->p; - } - ch = fgetc(i->file); - i->eof_flag = (ch == EOF); - i->peek_buf[0] = ch; - i->peek_buf[1] = '\0'; - i->p = i->peek_buf; - debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p); - return ch; + char *argv[2], **list; + + argv[0] = (char*)str; + argv[1] = NULL; + list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ + 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]); + debug_printf_expand("string_to_string='%s'\n", (char*)list); + return (char*)list; } -static void setup_file_in_str(struct in_str *i, FILE *f) +/* Used for "eval" builtin */ +static char* expand_strvec_to_string(char **argv) { - i->peek = file_peek; - i->get = file_get; -#if ENABLE_HUSH_INTERACTIVE - i->promptme = 1; - i->promptmode = 0; /* PS1 */ -#endif - i->file = f; - i->p = NULL; + char **list; + + list = expand_variables(argv, 0x80); + /* 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"); + list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */ + n++; + } + } + overlapping_strcpy((char*)list, list[0]); + debug_printf_expand("strvec_to_string='%s'\n", (char*)list); + return (char*)list; } -static void setup_string_in_str(struct in_str *i, const char *s) +static char **expand_assignments(char **argv, int count) { - i->peek = static_peek; - i->get = static_get; -#if ENABLE_HUSH_INTERACTIVE - i->promptme = 1; - i->promptmode = 0; /* PS1 */ -#endif - i->p = s; - i->eof_flag = 0; + int i; + char **p = NULL; + /* Expand assignments into one string each */ + for (i = 0; i < count; i++) { + p = add_string_to_strings(p, expand_string_to_string(argv[i])); + } + return p; } @@ -1469,22 +1814,104 @@ static void restore_redirects(int squirrel[]) } } -static char **expand_assignments(char **argv, int count) + +#if !defined(DEBUG_CLEAN) +#define free_pipe_list(head, indent) free_pipe_list(head) +#define free_pipe(pi, indent) free_pipe(pi) +#endif +static int free_pipe_list(struct pipe *head, int indent); + +/* return code is the exit status of the pipe */ +static int free_pipe(struct pipe *pi, int indent) { - int i; - char **p = NULL; - /* Expand assignments into one string each */ - for (i = 0; i < count; i++) { - p = add_string_to_strings(p, expand_string_to_string(argv[i])); + char **p; + struct command *command; + struct redir_struct *r, *rnext; + int a, i, ret_code = 0; + + if (pi->stopped_cmds > 0) + return ret_code; + debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid()); + for (i = 0; i < pi->num_cmds; i++) { + command = &pi->cmds[i]; + debug_printf_clean("%s command %d:\n", indenter(indent), i); + if (command->argv) { + for (a = 0, p = command->argv; *p; a++, p++) { + debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); + } + free_strings(command->argv); + command->argv = NULL; + } else if (command->group) { + debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type); + ret_code = free_pipe_list(command->group, indent+3); + debug_printf_clean("%s end group\n", indenter(indent)); + } else { + debug_printf_clean("%s (nil)\n", indenter(indent)); + } + for (r = command->redirects; r; r = rnext) { + debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip); + if (r->dup == -1) { + /* guard against the case >$FOO, where foo is unset or blank */ + if (r->rd_filename) { + debug_printf_clean(" %s\n", r->rd_filename); + free(r->rd_filename); + r->rd_filename = NULL; + } + } else { + debug_printf_clean("&%d\n", r->dup); + } + rnext = r->next; + free(r); + } + command->redirects = NULL; } - return p; + 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 + return ret_code; } +static int free_pipe_list(struct pipe *head, int indent) +{ + int rcode = 0; /* if list has no members */ + struct pipe *pi, *next; + + for (pi = head; pi; pi = next) { +#if HAS_KEYWORDS + debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word); +#endif + rcode = free_pipe(pi, indent); + debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup); + next = pi->next; + /*pi->next = NULL;*/ + free(pi); + } + return rcode; +} + + +#if !BB_MMU +typedef struct nommu_save_t { + char **new_env; + char **old_env; + char **argv; +} nommu_save_t; +#else +#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 + /* Called after [v]fork() in run_pipe(), or from builtin_exec(). * Never returns. * XXX no 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 void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) { int rcode; @@ -1554,8 +1981,11 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignme _exit(EXIT_FAILURE); } +static int run_list(struct pipe *pi); + /* 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) @@ -2461,77 +2891,6 @@ static int run_list(struct pipe *pi) return rcode; } -/* return code is the exit status of the pipe */ -static int free_pipe(struct pipe *pi, int indent) -{ - char **p; - struct command *command; - struct redir_struct *r, *rnext; - int a, i, ret_code = 0; - - if (pi->stopped_cmds > 0) - return ret_code; - debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid()); - for (i = 0; i < pi->num_cmds; i++) { - command = &pi->cmds[i]; - debug_printf_clean("%s command %d:\n", indenter(indent), i); - if (command->argv) { - for (a = 0, p = command->argv; *p; a++, p++) { - debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); - } - free_strings(command->argv); - command->argv = NULL; - } else if (command->group) { - debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type); - ret_code = free_pipe_list(command->group, indent+3); - debug_printf_clean("%s end group\n", indenter(indent)); - } else { - debug_printf_clean("%s (nil)\n", indenter(indent)); - } - for (r = command->redirects; r; r = rnext) { - debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip); - if (r->dup == -1) { - /* guard against the case >$FOO, where foo is unset or blank */ - if (r->rd_filename) { - debug_printf_clean(" %s\n", r->rd_filename); - free(r->rd_filename); - r->rd_filename = NULL; - } - } else { - debug_printf_clean("&%d\n", r->dup); - } - rnext = r->next; - free(r); - } - command->redirects = NULL; - } - 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 - return ret_code; -} - -static int free_pipe_list(struct pipe *head, int indent) -{ - int rcode = 0; /* if list has no members */ - struct pipe *pi, *next; - - for (pi = head; pi; pi = next) { -#if HAS_KEYWORDS - debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word); -#endif - rcode = free_pipe(pi, indent); - debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup); - next = pi->next; - /*pi->next = NULL;*/ - free(pi); - } - return rcode; -} - /* Select which version we will use */ static int run_and_free_list(struct pipe *pi) { @@ -2550,402 +2909,32 @@ static int run_and_free_list(struct pipe *pi) } -/* 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_quote || !output->o_glob) - o_addQstr(output, str, word_len); - else /* protect backslashes against globbing up :) */ - o_addstr_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; -} - -/* 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 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 first_ch, ored_ch; - int i; - const char *val; - char *p; - - ored_ch = 0; - - debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); - 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) { -#if ENABLE_HUSH_TICK - o_string subst_result = NULL_O_STRING; -#endif - o_addstr(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 */ - /* "$@" is special. Even if quoted, it can still - * expand to nothing (not even an empty string) */ - if ((first_ch & 0x7f) != '@') - ored_ch |= first_ch; - val = NULL; - switch (first_ch & 0x7f) { - /* Highest bit in first_ch indicates that var is double-quoted */ - case '$': /* pid */ - val = utoa(G.root_pid); - break; - case '!': /* bg pid */ - val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)""; - break; - case '?': /* exitcode */ - val = utoa(G.last_return_code); - break; - case '#': /* argc */ - val = utoa(G.global_argc ? G.global_argc-1 : 0); - break; - 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 $@ */ - smallint sv = output->o_quote; - /* unquoted var's contents should be globbed, so don't quote */ - output->o_quote = 0; - while (G.global_argv[i]) { - n = expand_on_ifs(output, n, G.global_argv[i]); - debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); - if (G.global_argv[i++][0] && G.global_argv[i]) { - /* this argv[] is not empty and not last: - * put terminating NUL, start new word */ - o_addchr(output, '\0'); - debug_print_list("expand_vars_to_list[2]", output, n); - n = o_save_ptr(output, n); - debug_print_list("expand_vars_to_list[3]", output, n); - } - } - output->o_quote = sv; - } else - /* If or_mask is nonzero, we handle assignment 'a=....$@.....' - * 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], strlen(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], strlen(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: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */ - /* "Empty variable", used to make "" etc to not disappear */ - arg++; - ored_ch = 0x80; - break; -#if ENABLE_HUSH_TICK - case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ - struct in_str input; - *p = '\0'; - arg++; -//TODO: can we just stuff it into "output" directly? - debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); - setup_string_in_str(&input, arg); - process_command_subs(&subst_result, &input, NULL); - debug_printf_subst("SUBST RES '%s'\n", subst_result.data); - val = subst_result.data; - goto store_val; - } -#endif - default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */ - *p = '\0'; - arg[0] = first_ch & 0x7f; - if (isdigit(arg[0])) { - i = xatoi_u(arg); - if (i < G.global_argc) - val = G.global_argv[i]; - /* else val remains NULL: $N with too big N */ - } else - val = lookup_param(arg); - arg[0] = first_ch; -#if ENABLE_HUSH_TICK - store_val: -#endif - *p = SPECIAL_VAR_SYMBOL; - if (!(first_ch & 0x80)) { /* unquoted $VAR */ - debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote); - if (val) { - /* unquoted var's contents should be globbed, so don't quote */ - smallint sv = output->o_quote; - output->o_quote = 0; - n = expand_on_ifs(output, n, val); - val = NULL; - output->o_quote = sv; - } - } else { /* quoted $VAR, val will be appended below */ - debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote); - } - } - if (val) { - o_addQstr(output, val, strlen(val)); - } - -#if ENABLE_HUSH_TICK - o_free(&subst_result); -#endif - arg = ++p; - } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ - - if (arg[0]) { - debug_print_list("expand_vars_to_list[a]", output, n); - /* this part is literal, and it was already pre-quoted - * if needed (much earlier), do not use o_addQstr here! */ - o_addstr(output, arg, strlen(arg) + 1); - debug_print_list("expand_vars_to_list[b]", output, n); - } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ - && !(ored_ch & 0x80) /* and all vars were not quoted. */ - ) { - n--; - /* allow to reuse list[n] later without re-growth */ - output->has_empty_slot = 1; - } else { - o_addchr(output, '\0'); - } - return n; -} - -static char **expand_variables(char **argv, int or_mask) -{ - int n; - char **list; - char **v; - o_string output = NULL_O_STRING; - - if (or_mask & 0x100) { - output.o_quote = 1; /* protect against globbing for "$var" */ - /* (unquoted $var will temporarily switch it off) */ - output.o_glob = 1; - } - - n = 0; - v = argv; - while (*v) { - n = expand_vars_to_list(&output, n, *v, (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, 0x100); -} - -/* 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) -{ - char *argv[2], **list; - - argv[0] = (char*)str; - argv[1] = NULL; - list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ - 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]); - 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; - - list = expand_variables(argv, 0x80); - /* 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"); - list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */ - n++; - } - } - overlapping_strcpy((char*)list, list[0]); - debug_printf_expand("strvec_to_string='%s'\n", (char*)list); - return (char*)list; -} - - -/* Used to get/check local shell variables */ -static struct variable *get_local_var(const char *name) -{ - struct variable *cur; - int len; - - if (!name) - return NULL; - len = strlen(name); - for (cur = G.top_var; cur; cur = cur->next) { - if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') - return cur; - } - return NULL; -} - -/* str holds "NAME=VAL" and is expected to be malloced. - * We take ownership of it. */ -static int set_local_var(char *str, int flg_export) +/* Peek ahead in the in_str to find out if we have a "&n" construct, + * as in "2>&1", that represents duplicating a file descriptor. + * Return either -2 (syntax error), -1 (no &), or the number found. + */ +static int redirect_dup_num(struct in_str *input) { - struct variable *cur; - char *value; - int name_len; - - value = strchr(str, '='); - if (!value) { /* not expected to ever happen? */ - free(str); - return -1; - } + int ch, d = 0, ok = 0; + ch = i_peek(input); + if (ch != '&') return -1; - name_len = value - str + 1; /* including '=' */ - cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ - while (1) { - if (strncmp(cur->varstr, str, name_len) != 0) { - if (!cur->next) { - /* Bail out. Note that now cur points - * to last var in linked list */ - break; - } - cur = cur->next; - continue; - } - /* We found an existing var with this name */ - *value = '\0'; - if (cur->flg_read_only) { - bb_error_msg("%s: readonly variable", str); - free(str); - return -1; - } - debug_printf_env("%s: unsetenv '%s'\n", __func__, str); - unsetenv(str); /* just in case */ - *value = '='; - if (strcmp(cur->varstr, str) == 0) { - free_and_exp: - free(str); - goto exp; - } - if (cur->max_len >= strlen(str)) { - /* This one is from startup env, reuse space */ - strcpy(cur->varstr, str); - goto free_and_exp; - } - /* max_len == 0 signifies "malloced" var, which we can - * (and has to) free */ - if (!cur->max_len) - free(cur->varstr); - cur->max_len = 0; - goto set_str_and_exp; + i_getch(input); /* get the & */ + ch = i_peek(input); + if (ch == '-') { + i_getch(input); + return -3; /* "-" represents "close me" */ } - - /* Not found - create next variable struct */ - cur->next = xzalloc(sizeof(*cur)); - cur = cur->next; - - set_str_and_exp: - cur->varstr = str; - exp: - if (flg_export) - cur->flg_export = 1; - if (cur->flg_export) { - debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr); - return putenv(cur->varstr); + while (isdigit(ch)) { + d = d*10 + (ch-'0'); + ok = 1; + i_getch(input); + ch = i_peek(input); } - return 0; -} - -static void unset_local_var(const char *name) -{ - struct variable *cur; - struct variable *prev = prev; /* for gcc */ - int name_len; + if (ok) return d; - if (!name) - return; - name_len = strlen(name); - cur = G.top_var; - while (cur) { - if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { - if (cur->flg_read_only) { - bb_error_msg("%s: readonly variable", name); - return; - } - /* prev is ok to use here because 1st variable, HUSH_VERSION, - * is ro, and we cannot reach this code on the 1st pass */ - prev->next = cur->next; - debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr); - bb_unsetenv(cur->varstr); - if (!cur->max_len) - free(cur->varstr); - free(cur); - return; - } - prev = cur; - cur = cur->next; - } + bb_error_msg("ambiguous redirect"); + return -2; } /* The src parameter allows us to peek forward to a possible &n syntax @@ -2997,6 +2986,7 @@ static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, return 0; } + static struct pipe *new_pipe(void) { struct pipe *pi; @@ -3006,6 +2996,91 @@ static struct pipe *new_pipe(void) return pi; } +/* Command (member of a pipe) is complete. The only possible error here + * is out of memory, in which case xmalloc exits. */ +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; + + if (command) { + if (command->group == NULL + && command->argv == NULL + && command->redirects == NULL + ) { + debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); + return pi->num_cmds; + } + pi->num_cmds++; + debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); + } else { + debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); + } + + /* 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)); + command = &pi->cmds[pi->num_cmds]; + memset(command, 0, sizeof(*command)); + + ctx->command = command; + /* but ctx->pipe and ctx->list_head remain unchanged */ + + return pi->num_cmds; /* used only for 0/nonzero check */ +} + +static void done_pipe(struct parse_context *ctx, pipe_style type) +{ + int not_null; + + 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;) + IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;) + IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;) + + /* Without this check, even just <enter> on command line generates + * tree of three NOPs (!). Which is harmless but annoying. + * IOW: it is safe to do it unconditionally. + * RES_NONE case is for "for a in; do ..." (empty IN set) + * to work, possibly other cases too. */ + if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) { + 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; + ctx->command = NULL; /* needed! */ + /* RES_THEN, RES_DO etc are "sticky" - + * they remain set for commands 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_CASEI; +#endif + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); + } + debug_printf_parse("done_pipe return\n"); +} + static void initialize_context(struct parse_context *ctx) { memset(ctx, 0, sizeof(*ctx)); @@ -3017,6 +3092,7 @@ static void initialize_context(struct parse_context *ctx) done_command(ctx); } + /* If a reserved word is found and processed, parse context is modified * and 1 is returned. * Handles if, then, elif, else, fi, for, while, until, do, done. @@ -3260,119 +3336,6 @@ static int done_word(o_string *word, struct parse_context *ctx) return 0; } -/* Command (member of a pipe) is complete. The only possible error here - * is out of memory, in which case xmalloc exits. */ -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; - - if (command) { - if (command->group == NULL - && command->argv == NULL - && command->redirects == NULL - ) { - debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); - return pi->num_cmds; - } - pi->num_cmds++; - debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); - } else { - debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); - } - - /* 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)); - command = &pi->cmds[pi->num_cmds]; - memset(command, 0, sizeof(*command)); - - ctx->command = command; - /* but ctx->pipe and ctx->list_head remain unchanged */ - - return pi->num_cmds; /* used only for 0/nonzero check */ -} - -static void done_pipe(struct parse_context *ctx, pipe_style type) -{ - int not_null; - - 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;) - IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;) - IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;) - - /* Without this check, even just <enter> on command line generates - * tree of three NOPs (!). Which is harmless but annoying. - * IOW: it is safe to do it unconditionally. - * RES_NONE case is for "for a in; do ..." (empty IN set) - * to work, possibly other cases too. */ - if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) { - 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; - ctx->command = NULL; /* needed! */ - /* RES_THEN, RES_DO etc are "sticky" - - * they remain set for commands 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_CASEI; -#endif - /* Create the memory for command, roughly: - * ctx->pipe->cmds = new struct command; - * ctx->command = &ctx->pipe->cmds[0]; - */ - done_command(ctx); - } - debug_printf_parse("done_pipe return\n"); -} - -/* Peek ahead in the in_str to find out if we have a "&n" construct, - * as in "2>&1", that represents duplicating a file descriptor. - * Return either -2 (syntax error), -1 (no &), or the number found. - */ -static int redirect_dup_num(struct in_str *input) -{ - int ch, d = 0, ok = 0; - ch = i_peek(input); - if (ch != '&') return -1; - - i_getch(input); /* get the & */ - ch = i_peek(input); - if (ch == '-') { - i_getch(input); - return -3; /* "-" represents "close me" */ - } - while (isdigit(ch)) { - d = d*10 + (ch-'0'); - ok = 1; - i_getch(input); - ch = i_peek(input); - } - if (ok) return d; - - bb_error_msg("ambiguous redirect"); - return -2; -} - /* 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 @@ -3444,6 +3407,9 @@ static FILE *generate_stream_from_list(struct pipe *head) /* 'head' is freed by the caller */ } +static int parse_stream(o_string *dest, struct parse_context *ctx, + struct in_str *input0, const char *end_trigger); + /* Return code is exit status of the process that is run. */ static int process_command_subs(o_string *dest, struct in_str *input, @@ -3544,16 +3510,6 @@ static int parse_group(o_string *dest, struct parse_context *ctx, /* command remains "open", available for possible redirects */ } -/* Basically useful version until someone wants to get fancier, - * see the bash man page under "Parameter Expansion" */ -static const char *lookup_param(const char *src) -{ - struct variable *var = get_local_var(src); - if (var) - return strchr(var->varstr, '=') + 1; - return NULL; -} - #if ENABLE_HUSH_TICK /* Subroutines for copying $(...) and `...` things */ static void add_till_backquote(o_string *dest, struct in_str *input); @@ -3761,7 +3717,7 @@ static int handle_dollar(o_string *dest, struct in_str *input) * -1 on EOF (but if end_trigger == NULL then return 0), * 1 for syntax error */ static int parse_stream(o_string *dest, struct parse_context *ctx, - struct in_str *input, const char *end_trigger) + struct in_str *input, const char *end_trigger) { int ch, m; int redir_fd; @@ -4680,45 +4636,49 @@ static int builtin_read(char **argv) */ static int builtin_set(char **argv) { - struct variable *e; - char **pp; + int n; + char **pp, **g_argv; char *arg = *++argv; if (arg == NULL) { + struct variable *e; for (e = G.top_var; e; e = e->next) puts(e->varstr); - } else { - /* NB: G.global_argv[0] ($0) is never freed/changed */ + return EXIT_SUCCESS; + } - if (G.global_args_malloced) { - pp = G.global_argv; - while (*++pp) - free(*pp); - G.global_argv[1] = NULL; - } else { - G.global_args_malloced = 1; - pp = xzalloc(sizeof(pp[0]) * 2); - pp[0] = G.global_argv[0]; /* retain $0 */ - G.global_argv = pp; + do { + if (arg[0] == '+') + continue; + if (arg[0] != '-') + break; + if (arg[1] == '-' && arg[2] == '\0') { + argv++; + break; } - do { - if (arg[0] == '+') - continue; - if (arg[0] != '-') - break; - if (arg[1] == '-' && arg[2] == '\0') { - argv++; - break; - } - } while ((arg = *++argv) != NULL); - /* Now argv[0] is 1st argument */ + } while ((arg = *++argv) != NULL); + /* Now argv[0] is 1st argument */ - /* This realloc's G.global_argv */ - G.global_argv = pp = add_strings_to_strings(G.global_argv, argv, /*dup:*/ 1); - G.global_argc = 1; + /* NB: G.global_argv[0] ($0) is never freed/changed */ + g_argv = G.global_argv; + if (G.global_args_malloced) { + pp = g_argv; while (*++pp) - G.global_argc++; + free(*pp); + g_argv[1] = NULL; + } else { + G.global_args_malloced = 1; + pp = xzalloc(sizeof(pp[0]) * 2); + pp[0] = g_argv[0]; /* retain $0 */ + g_argv = pp; } + /* This realloc's G.global_argv */ + G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1); + + n = 1; + while (*++pp) + n++; + G.global_argc = n; return EXIT_SUCCESS; } |