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Diffstat (limited to 'hush.c')
| -rw-r--r-- | hush.c | 2695 |
1 files changed, 0 insertions, 2695 deletions
@@ -1,2695 +0,0 @@ -/* 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. - * - * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> - * - * Credits: - * The parser routines proper are all original material, first - * written Dec 2000 and Jan 2001 by Larry Doolittle. - * The execution engine, the builtins, and much of the underlying - * support has been adapted from busybox-0.49pre's lash, - * which is Copyright (C) 2000 by Lineo, Inc., and - * written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>. - * That, in turn, is based in part on ladsh.c, by Michael K. Johnson and - * Erik W. Troan, which they placed in the public domain. I don't know - * how much of the Johnson/Troan code has survived the repeated rewrites. - * Other credits: - * simple_itoa() was lifted from boa-0.93.15 - * b_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 - * - * There are two big (and related) architecture differences between - * this parser and the lash parser. One is that this version is - * actually designed from the ground up to understand nearly all - * of the Bourne grammar. The second, consequential change is that - * the parser and input reader have been turned inside out. Now, - * the parser is in control, and asks for input as needed. The old - * way had the input reader in control, and it asked for parsing to - * take place as needed. The new way makes it much easier to properly - * handle the recursion implicit in the various substitutions, especially - * across continuation lines. - * - * Bash grammar not implemented: (how many of these were in original sh?) - * $@ (those sure look like weird quoting rules) - * $_ - * ! negation operator for pipes - * &> and >& redirection of stdout+stderr - * Brace Expansion - * Tilde Expansion - * fancy forms of Parameter Expansion - * aliases - * Arithmetic Expansion - * <(list) and >(list) Process Substitution - * reserved words: case, esac, select, function - * Here Documents ( << word ) - * Functions - * Major bugs: - * job handling woefully incomplete and buggy - * reserved word execution woefully incomplete and buggy - * to-do: - * port selected bugfixes from post-0.49 busybox lash - done? - * finish implementing reserved words: for, while, until, do, done - * change { and } from special chars to reserved words - * builtins: break, continue, eval, return, set, trap, ulimit - * test magic exec - * handle children going into background - * clean up recognition of null pipes - * check setting of global_argc and global_argv - * control-C handling, probably with longjmp - * follow IFS rules more precisely, including update semantics - * figure out what to do with backslash-newline - * explain why we use signal instead of sigaction - * propagate syntax errors, die on resource errors? - * continuation lines, both explicit and implicit - done? - * memory leak finding and plugging - done? - * more testing, especially quoting rules and redirection - * document how quoting rules not precisely followed for variable assignments - * maybe change map[] to use 2-bit entries - * (eventually) remove all the printf's - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -#include <ctype.h> /* isalpha, isdigit */ -#include <unistd.h> /* getpid */ -#include <stdlib.h> /* getenv, atoi */ -#include <string.h> /* strchr */ -#include <stdio.h> /* popen etc. */ -#include <glob.h> /* glob, of course */ -#include <stdarg.h> /* va_list */ -#include <errno.h> -#include <fcntl.h> -#include <getopt.h> /* should be pretty obvious */ - -#include <sys/stat.h> /* ulimit */ -#include <sys/types.h> -#include <sys/wait.h> -#include <signal.h> - -/* #include <dmalloc.h> */ -/* #define DEBUG_SHELL */ - -#ifdef BB_VER -#include "busybox.h" -#include "cmdedit.h" -#else -#define applet_name "hush" -#include "standalone.h" -#define hush_main main -#undef BB_FEATURE_SH_FANCY_PROMPT -#endif - -typedef enum { - REDIRECT_INPUT = 1, - REDIRECT_OVERWRITE = 2, - REDIRECT_APPEND = 3, - REDIRECT_HEREIS = 4, - REDIRECT_IO = 5 -} redir_type; - -/* The descrip member of this structure is only used to make debugging - * output pretty */ -struct {int mode; int default_fd; char *descrip;} redir_table[] = { - { 0, 0, "()" }, - { O_RDONLY, 0, "<" }, - { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, - { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, - { O_RDONLY, -1, "<<" }, - { O_RDWR, 1, "<>" } -}; - -typedef enum { - PIPE_SEQ = 1, - PIPE_AND = 2, - PIPE_OR = 3, - PIPE_BG = 4, -} pipe_style; - -/* might eventually control execution */ -typedef enum { - RES_NONE = 0, - RES_IF = 1, - RES_THEN = 2, - RES_ELIF = 3, - RES_ELSE = 4, - RES_FI = 5, - RES_FOR = 6, - RES_WHILE = 7, - RES_UNTIL = 8, - RES_DO = 9, - RES_DONE = 10, - RES_XXXX = 11, - RES_SNTX = 12 -} reserved_style; -#define FLAG_END (1<<RES_NONE) -#define FLAG_IF (1<<RES_IF) -#define FLAG_THEN (1<<RES_THEN) -#define FLAG_ELIF (1<<RES_ELIF) -#define FLAG_ELSE (1<<RES_ELSE) -#define FLAG_FI (1<<RES_FI) -#define FLAG_FOR (1<<RES_FOR) -#define FLAG_WHILE (1<<RES_WHILE) -#define FLAG_UNTIL (1<<RES_UNTIL) -#define FLAG_DO (1<<RES_DO) -#define FLAG_DONE (1<<RES_DONE) -#define FLAG_START (1<<RES_XXXX) - -/* This holds pointers to the various results of parsing */ -struct p_context { - struct child_prog *child; - struct pipe *list_head; - struct pipe *pipe; - struct redir_struct *pending_redirect; - reserved_style w; - int old_flag; /* for figuring out valid reserved words */ - struct p_context *stack; - /* How about quoting status? */ -}; - -struct redir_struct { - redir_type type; /* type of redirection */ - int fd; /* file descriptor being redirected */ - int dup; /* -1, or file descriptor being duplicated */ - struct redir_struct *next; /* pointer to the next redirect in the list */ - glob_t word; /* *word.gl_pathv is the filename */ -}; - -struct child_prog { - pid_t pid; /* 0 if exited */ - char **argv; /* program name and arguments */ - struct pipe *group; /* if non-NULL, first in group or subshell */ - int subshell; /* flag, non-zero if group must be forked */ - struct redir_struct *redirects; /* I/O redirections */ - glob_t glob_result; /* result of parameter globbing */ - int is_stopped; /* is the program currently running? */ - struct pipe *family; /* pointer back to the child's parent pipe */ -}; - -struct pipe { - int jobid; /* job number */ - int num_progs; /* total number of programs in job */ - int running_progs; /* number of programs running */ - char *text; /* name of job */ - char *cmdbuf; /* buffer various argv's point into */ - pid_t pgrp; /* process group ID for the job */ - struct child_prog *progs; /* array of commands in pipe */ - struct pipe *next; /* to track background commands */ - int stopped_progs; /* number of programs alive, but stopped */ - int job_context; /* bitmask defining current context */ - pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ - reserved_style r_mode; /* supports if, for, while, until */ -}; - -struct close_me { - int fd; - struct close_me *next; -}; - -struct variables { - char *name; - char *value; - int flg_export; - int flg_read_only; - struct variables *next; -}; - -/* globals, connect us to the outside world - * the first three support $?, $#, and $1 */ -char **global_argv; -unsigned int global_argc; -unsigned int last_return_code; -extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */ - -/* "globals" within this file */ -static char *ifs; -static char map[256]; -static int fake_mode; -static int interactive; -static struct close_me *close_me_head; -static const char *cwd; -static struct pipe *job_list; -static unsigned int last_bg_pid; -static unsigned int last_jobid; -static unsigned int shell_terminal; -static char *PS1; -static char *PS2; -struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 }; -struct variables *top_vars = &shell_ver; - - -#define B_CHUNK (100) -#define B_NOSPAC 1 - -typedef struct { - char *data; - int length; - int maxlen; - int quote; - int nonnull; -} o_string; -#define NULL_O_STRING {NULL,0,0,0,0} -/* used for initialization: - o_string foo = NULL_O_STRING; */ - -/* I can almost use ordinary FILE *. Is open_memstream() universally - * available? Where is it documented? */ -struct in_str { - const char *p; - char peek_buf[2]; - int __promptme; - int promptmode; - FILE *file; - int (*get) (struct in_str *); - int (*peek) (struct in_str *); -}; -#define b_getch(input) ((input)->get(input)) -#define b_peek(input) ((input)->peek(input)) - -#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" - -struct built_in_command { - char *cmd; /* name */ - char *descr; /* description */ - int (*function) (struct child_prog *); /* function ptr */ -}; - -/* belongs in busybox.h */ -static inline int max(int a, int b) { - return (a>b)?a:b; -} - -/* This should be in utility.c */ -#ifdef DEBUG_SHELL -static void debug_printf(const char *format, ...) -{ - va_list args; - va_start(args, format); - vfprintf(stderr, format, args); - va_end(args); -} -#else -static inline void debug_printf(const char *format, ...) { } -#endif -#define final_printf debug_printf - -static void __syntax(char *file, int line) { - error_msg("syntax error %s:%d", file, line); -} -#define syntax() __syntax(__FILE__, __LINE__) - -/* Index of subroutines: */ -/* function prototypes for builtins */ -static int builtin_cd(struct child_prog *child); -static int builtin_env(struct child_prog *child); -static int builtin_exec(struct child_prog *child); -static int builtin_exit(struct child_prog *child); -static int builtin_export(struct child_prog *child); -static int builtin_fg_bg(struct child_prog *child); -static int builtin_help(struct child_prog *child); -static int builtin_jobs(struct child_prog *child); -static int builtin_pwd(struct child_prog *child); -static int builtin_read(struct child_prog *child); -static int builtin_set(struct child_prog *child); -static int builtin_shift(struct child_prog *child); -static int builtin_source(struct child_prog *child); -static int builtin_umask(struct child_prog *child); -static int builtin_unset(struct child_prog *child); -static int builtin_not_written(struct child_prog *child); -/* o_string manipulation: */ -static int b_check_space(o_string *o, int len); -static int b_addchr(o_string *o, int ch); -static void b_reset(o_string *o); -static int b_addqchr(o_string *o, int ch, int quote); -static int b_adduint(o_string *o, unsigned int i); -/* 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); -/* close_me manipulations: */ -static void mark_open(int fd); -static void mark_closed(int fd); -static void close_all(); -/* "run" the final data structures: */ -static char *indenter(int i); -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: */ -static int setup_redirects(struct child_prog *prog, int squirrel[]); -static int run_list_real(struct pipe *pi); -static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn)); -static int run_pipe_real(struct pipe *pi); -/* extended glob support: */ -static int globhack(const char *src, int flags, glob_t *pglob); -static int glob_needed(const char *s); -static int xglob(o_string *dest, int flags, glob_t *pglob); -/* variable assignment: */ -static int is_assignment(const char *s); -/* data structure manipulation: */ -static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input); -static void initialize_context(struct p_context *ctx); -static int done_word(o_string *dest, struct p_context *ctx); -static int done_command(struct p_context *ctx); -static int done_pipe(struct p_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); -static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end); -static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch); -static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src); -static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input); -static int parse_string(o_string *dest, struct p_context *ctx, const char *src); -static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger); -/* setup: */ -static int parse_stream_outer(struct in_str *inp); -static int parse_string_outer(const char *s); -static int parse_file_outer(FILE *f); -/* job management: */ -static int checkjobs(struct pipe* fg_pipe); -static void insert_bg_job(struct pipe *pi); -static void remove_bg_job(struct pipe *pi); -/* local variable support */ -static char *get_local_var(const char *var); -static void unset_local_var(const char *name); -static int set_local_var(const char *s, int flg_export); - -/* 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 can not. - * For example, 'unset foo | whatever' will parse and run, but foo will - * still be set at the end. */ -static struct built_in_command bltins[] = { - {"bg", "Resume a job in the background", builtin_fg_bg}, - {"break", "Exit for, while or until loop", builtin_not_written}, - {"cd", "Change working directory", builtin_cd}, - {"continue", "Continue for, while or until loop", builtin_not_written}, - {"env", "Print all environment variables", builtin_env}, - {"eval", "Construct and run shell command", builtin_not_written}, - {"exec", "Exec command, replacing this shell with the exec'd process", - builtin_exec}, - {"exit", "Exit from shell()", builtin_exit}, - {"export", "Set environment variable", builtin_export}, - {"fg", "Bring job into the foreground", builtin_fg_bg}, - {"jobs", "Lists the active jobs", builtin_jobs}, - {"pwd", "Print current directory", builtin_pwd}, - {"read", "Input environment variable", builtin_read}, - {"return", "Return from a function", builtin_not_written}, - {"set", "Set/unset shell local variables", builtin_set}, - {"shift", "Shift positional parameters", builtin_shift}, - {"trap", "Trap signals", builtin_not_written}, - {"ulimit","Controls resource limits", builtin_not_written}, - {"umask","Sets file creation mask", builtin_umask}, - {"unset", "Unset environment variable", builtin_unset}, - {".", "Source-in and run commands in a file", builtin_source}, - {"help", "List shell built-in commands", builtin_help}, - {NULL, NULL, NULL} -}; - -static const char *set_cwd(void) -{ - if(cwd==unknown) - cwd = NULL; /* xgetcwd(arg) called free(arg) */ - cwd = xgetcwd((char *)cwd); - if (!cwd) - cwd = unknown; - return cwd; -} - - -/* built-in 'cd <path>' handler */ -static int builtin_cd(struct child_prog *child) -{ - char *newdir; - if (child->argv[1] == NULL) - newdir = getenv("HOME"); - else - newdir = child->argv[1]; - if (chdir(newdir)) { - printf("cd: %s: %s\n", newdir, strerror(errno)); - return EXIT_FAILURE; - } - set_cwd(); - return EXIT_SUCCESS; -} - -/* built-in 'env' handler */ -static int builtin_env(struct child_prog *dummy) -{ - char **e = environ; - if (e == NULL) return EXIT_FAILURE; - for (; *e; e++) { - puts(*e); - } - return EXIT_SUCCESS; -} - -/* built-in 'exec' handler */ -static int builtin_exec(struct child_prog *child) -{ - if (child->argv[1] == NULL) - return EXIT_SUCCESS; /* Really? */ - child->argv++; - pseudo_exec(child); - /* never returns */ -} - -/* built-in 'exit' handler */ -static int builtin_exit(struct child_prog *child) -{ - if (child->argv[1] == NULL) - exit(last_return_code); - exit (atoi(child->argv[1])); -} - -/* built-in 'export VAR=value' handler */ -static int builtin_export(struct child_prog *child) -{ - int res = 0; - char *name = child->argv[1]; - - if (name == NULL) { - return (builtin_env(child)); - } - - name = strdup(name); - - if(name) { - char *value = strchr(name, '='); - - if (!value) { - char *tmp; - /* They are exporting something without an =VALUE */ - - value = get_local_var(name); - if (value) { - size_t ln = strlen(name); - - tmp = realloc(name, ln+strlen(value)+2); - if(tmp==NULL) - res = -1; - else { - sprintf(tmp+ln, "=%s", value); - name = tmp; - } - } else { - /* bash does not return an error when trying to export - * an undefined variable. Do likewise. */ - res = 1; - } - } - } - if (res<0) - perror_msg("export"); - else if(res==0) - res = set_local_var(name, 1); - else - res = 0; - free(name); - return res; -} - -/* built-in 'fg' and 'bg' handler */ -static int builtin_fg_bg(struct child_prog *child) -{ - int i, jobnum; - struct pipe *pi=NULL; - - if (!interactive) - return EXIT_FAILURE; - /* If they gave us no args, assume they want the last backgrounded task */ - if (!child->argv[1]) { - for (pi = job_list; pi; pi = pi->next) { - if (pi->jobid == last_jobid) { - break; - } - } - if (!pi) { - error_msg("%s: no current job", child->argv[0]); - return EXIT_FAILURE; - } - } else { - if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) { - error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]); - return EXIT_FAILURE; - } - for (pi = job_list; pi; pi = pi->next) { - if (pi->jobid == jobnum) { - break; - } - } - if (!pi) { - error_msg("%s: %d: no such job", child->argv[0], jobnum); - return EXIT_FAILURE; - } - } - - if (*child->argv[0] == 'f') { - /* Put the job into the foreground. */ - tcsetpgrp(shell_terminal, pi->pgrp); - } - - /* Restart the processes in the job */ - for (i = 0; i < pi->num_progs; i++) - pi->progs[i].is_stopped = 0; - - if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) { - if (i == ESRCH) { - remove_bg_job(pi); - } else { - perror_msg("kill (SIGCONT)"); - } - } - - pi->stopped_progs = 0; - return EXIT_SUCCESS; -} - -/* built-in 'help' handler */ -static int builtin_help(struct child_prog *dummy) -{ - struct built_in_command *x; - - printf("\nBuilt-in commands:\n"); - printf("-------------------\n"); - for (x = bltins; x->cmd; x++) { - if (x->descr==NULL) - continue; - printf("%s\t%s\n", x->cmd, x->descr); - } - printf("\n\n"); - return EXIT_SUCCESS; -} - -/* built-in 'jobs' handler */ -static int builtin_jobs(struct child_prog *child) -{ - struct pipe *job; - char *status_string; - - for (job = job_list; job; job = job->next) { - if (job->running_progs == job->stopped_progs) - status_string = "Stopped"; - else - status_string = "Running"; - - printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text); - } - return EXIT_SUCCESS; -} - - -/* built-in 'pwd' handler */ -static int builtin_pwd(struct child_prog *dummy) -{ - puts(set_cwd()); - return EXIT_SUCCESS; -} - -/* built-in 'read VAR' handler */ -static int builtin_read(struct child_prog *child) -{ - int res; - - if (child->argv[1]) { - char string[BUFSIZ]; - char *var = 0; - - string[0] = 0; /* In case stdin has only EOF */ - /* read string */ - fgets(string, sizeof(string), stdin); - chomp(string); - var = malloc(strlen(child->argv[1])+strlen(string)+2); - if(var) { - sprintf(var, "%s=%s", child->argv[1], string); - res = set_local_var(var, 0); - } else - res = -1; - if (res) - fprintf(stderr, "read: %m\n"); - free(var); /* So not move up to avoid breaking errno */ - return res; - } else { - do res=getchar(); while(res!='\n' && res!=EOF); - return 0; - } -} - -/* built-in 'set VAR=value' handler */ -static int builtin_set(struct child_prog *child) -{ - char *temp = child->argv[1]; - struct variables *e; - - if (temp == NULL) - for(e = top_vars; e; e=e->next) - printf("%s=%s\n", e->name, e->value); - else - set_local_var(temp, 0); - - return EXIT_SUCCESS; -} - - -/* Built-in 'shift' handler */ -static int builtin_shift(struct child_prog *child) -{ - int n=1; - if (child->argv[1]) { - n=atoi(child->argv[1]); - } - if (n>=0 && n<global_argc) { - /* XXX This probably breaks $0 */ - global_argc -= n; - global_argv += n; - return EXIT_SUCCESS; - } else { - return EXIT_FAILURE; - } -} - -/* Built-in '.' handler (read-in and execute commands from file) */ -static int builtin_source(struct child_prog *child) -{ - FILE *input; - int status; - - if (child->argv[1] == NULL) - return EXIT_FAILURE; - - /* XXX search through $PATH is missing */ - input = fopen(child->argv[1], "r"); - if (!input) { - error_msg("Couldn't open file '%s'", child->argv[1]); - return EXIT_FAILURE; - } - - /* Now run the file */ - /* XXX argv and argc are broken; need to save old global_argv - * (pointer only is OK!) on this stack frame, - * set global_argv=child->argv+1, recurse, and restore. */ - mark_open(fileno(input)); - status = parse_file_outer(input); - mark_closed(fileno(input)); - fclose(input); - return (status); -} - -static int builtin_umask(struct child_prog *child) -{ - mode_t new_umask; - const char *arg = child->argv[1]; - char *end; - if (arg) { - new_umask=strtoul(arg, &end, 8); - if (*end!='\0' || end == arg) { - return EXIT_FAILURE; - } - } else { - printf("%.3o\n", (unsigned int) (new_umask=umask(0))); - } - umask(new_umask); - return EXIT_SUCCESS; -} - -/* built-in 'unset VAR' handler */ -static int builtin_unset(struct child_prog *child) -{ - /* bash returned already true */ - unset_local_var(child->argv[1]); - return EXIT_SUCCESS; -} - -static int builtin_not_written(struct child_prog *child) -{ - printf("builtin_%s not written\n",child->argv[0]); - return EXIT_FAILURE; -} - -static int b_check_space(o_string *o, int len) -{ - /* It would be easy to drop a more restrictive policy - * in here, such as setting a maximum string length */ - if (o->length + len > o->maxlen) { - char *old_data = o->data; - /* assert (data == NULL || o->maxlen != 0); */ - o->maxlen += max(2*len, B_CHUNK); - o->data = realloc(o->data, 1 + o->maxlen); - if (o->data == NULL) { - free(old_data); - } - } - return o->data == NULL; -} - -static int b_addchr(o_string *o, int ch) -{ - debug_printf("b_addchr: %c %d %p\n", ch, o->length, o); - if (b_check_space(o, 1)) return B_NOSPAC; - o->data[o->length] = ch; - o->length++; - o->data[o->length] = '\0'; - return 0; -} - -static void b_reset(o_string *o) -{ - o->length = 0; - o->nonnull = 0; - if (o->data != NULL) *o->data = '\0'; -} - -static void b_free(o_string *o) -{ - b_reset(o); - if (o->data != NULL) free(o->data); - o->data = NULL; - o->maxlen = 0; -} - -/* My analysis of quoting semantics tells me that state information - * is associated with a destination, not a source. - */ -static int b_addqchr(o_string *o, int ch, int quote) -{ - if (quote && strchr("*?[\\",ch)) { - int rc; - rc = b_addchr(o, '\\'); - if (rc) return rc; - } - return b_addchr(o, ch); -} - -/* belongs in utility.c */ -char *simple_itoa(unsigned int i) -{ - /* 21 digits plus null terminator, good for 64-bit or smaller ints */ - static char local[22]; - char *p = &local[21]; - *p-- = '\0'; - do { - *p-- = '0' + i % 10; - i /= 10; - } while (i > 0); - return p + 1; -} - -static int b_adduint(o_string *o, unsigned int i) -{ - int r; - char *p = simple_itoa(i); - /* no escape checking necessary */ - do r=b_addchr(o, *p++); while (r==0 && *p); - return r; -} - -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; -} - -static inline void cmdedit_set_initial_prompt(void) -{ -#ifndef BB_FEATURE_SH_FANCY_PROMPT - PS1 = NULL; -#else - PS1 = getenv("PS1"); - if(PS1==0) - PS1 = "\\w \\$ "; -#endif -} - -static inline void setup_prompt_string(int promptmode, char **prompt_str) -{ - debug_printf("setup_prompt_string %d ",promptmode); -#ifndef BB_FEATURE_SH_FANCY_PROMPT - /* Set up the prompt */ - if (promptmode == 1) { - if (PS1) - free(PS1); - PS1=xmalloc(strlen(cwd)+4); - sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# "); - *prompt_str = PS1; - } else { - *prompt_str = PS2; - } -#else - *prompt_str = (promptmode==1)? PS1 : PS2; -#endif - debug_printf("result %s\n",*prompt_str); -} - -static void get_user_input(struct in_str *i) -{ - char *prompt_str; - static char the_command[BUFSIZ]; - - setup_prompt_string(i->promptmode, &prompt_str); -#ifdef BB_FEATURE_COMMAND_EDITING - /* - ** enable command line editing only while a command line - ** is actually being read; otherwise, we'll end up bequeathing - ** atexit() handlers and other unwanted stuff to our - ** child processes (rob@sysgo.de) - */ - cmdedit_read_input(prompt_str, the_command); -#else - fputs(prompt_str, stdout); - fflush(stdout); - the_command[0]=fgetc(i->file); - the_command[1]='\0'; -#endif - fflush(stdout); - i->p = the_command; -} - -/* 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; - - ch = 0; - /* If there is data waiting, eat it up */ - if (i->p && *i->p) { - ch=*i->p++; - } else { - /* need to double check i->file because we might be doing something - * more complicated by now, like sourcing or substituting. */ - if (i->__promptme && interactive && i->file == stdin) { - while(! i->p || (interactive && strlen(i->p)==0) ) { - get_user_input(i); - } - i->promptmode=2; - i->__promptme = 0; - if (i->p && *i->p) { - ch=*i->p++; - } - } else { - ch = fgetc(i->file); - } - - debug_printf("b_getch: got a %d\n", ch); - } - if (ch == '\n') i->__promptme=1; - 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) -{ - if (i->p && *i->p) { - return *i->p; - } else { - i->peek_buf[0] = fgetc(i->file); - i->peek_buf[1] = '\0'; - i->p = i->peek_buf; - debug_printf("b_peek: got a %d\n", *i->p); - return *i->p; - } -} - -static void setup_file_in_str(struct in_str *i, FILE *f) -{ - i->peek = file_peek; - i->get = file_get; - i->__promptme=1; - i->promptmode=1; - 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; - i->__promptme=1; - i->promptmode=1; - i->p = s; -} - -static void mark_open(int fd) -{ - struct close_me *new = xmalloc(sizeof(struct close_me)); - new->fd = fd; - new->next = close_me_head; - close_me_head = new; -} - -static void mark_closed(int fd) -{ - struct close_me *tmp; - if (close_me_head == NULL || close_me_head->fd != fd) - error_msg_and_die("corrupt close_me"); - tmp = close_me_head; - close_me_head = close_me_head->next; - free(tmp); -} - -static void close_all() -{ - struct close_me *c; - for (c=close_me_head; c; c=c->next) { - close(c->fd); - } - close_me_head = NULL; -} - -/* squirrel != NULL means we squirrel away copies of stdin, stdout, - * and stderr if they are redirected. */ -static int setup_redirects(struct child_prog *prog, int squirrel[]) -{ - int openfd, mode; - struct redir_struct *redir; - - for (redir=prog->redirects; redir; redir=redir->next) { - if (redir->dup == -1 && redir->word.gl_pathv == NULL) { - /* something went wrong in the parse. Pretend it didn't happen */ - continue; - } - if (redir->dup == -1) { - mode=redir_table[redir->type].mode; - openfd = open(redir->word.gl_pathv[0], mode, 0666); - 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!) */ - perror_msg("error opening %s", redir->word.gl_pathv[0]); - return 1; - } - } else { - openfd = redir->dup; - } - - if (openfd != redir->fd) { - if (squirrel && redir->fd < 3) { - squirrel[redir->fd] = dup(redir->fd); - } - if (openfd == -3) { - close(openfd); - } else { - dup2(openfd, redir->fd); - if (redir->dup == -1) - close (openfd); - } - } - } - return 0; -} - -static void restore_redirects(int squirrel[]) -{ - int i, fd; - for (i=0; i<3; i++) { - fd = squirrel[i]; - if (fd != -1) { - /* No error checking. I sure wouldn't know what - * to do with an error if I found one! */ - dup2(fd, i); - close(fd); - } - } -} - -/* 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? */ -static void pseudo_exec(struct child_prog *child) -{ - int i, rcode; - struct built_in_command *x; - if (child->argv) { - for (i=0; is_assignment(child->argv[i]); i++) { - debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]); - putenv(strdup(child->argv[i])); - } - child->argv+=i; /* XXX this hack isn't so horrible, since we are about - to exit, and therefore don't need to keep data - structures consistent for free() use. */ - /* If a variable is assigned in a forest, and nobody listens, - * was it ever really set? - */ - if (child->argv[0] == NULL) { - _exit(EXIT_SUCCESS); - } - - /* - * 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. - */ - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[0], x->cmd) == 0 ) { - debug_printf("builtin exec %s\n", child->argv[0]); - rcode = x->function(child); - fflush(stdout); - _exit(rcode); - } - } - - /* Check if the command matches any busybox internal commands - * ("applets") here. - * FIXME: This feature is not 100% safe, since - * BusyBox is not fully reentrant, so we have no guarantee the things - * from the .bss are still zeroed, or that things from .data are still - * at their defaults. We could exec ourself from /proc/self/exe, but I - * really dislike relying on /proc for things. We could exec ourself - * from global_argv[0], but if we are in a chroot, we may not be able - * to find ourself... */ -#ifdef BB_FEATURE_SH_STANDALONE_SHELL - { - int argc_l; - char** argv_l=child->argv; - char *name = child->argv[0]; - -#ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN - /* Following discussions from November 2000 on the busybox mailing - * list, the default configuration, (without - * get_last_path_component()) lets the user force use of an - * external command by specifying the full (with slashes) filename. - * If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets - * _aways_ override external commands, so if you want to run - * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the - * filesystem and is _not_ busybox. Some systems may want this, - * most do not. */ - name = get_last_path_component(name); -#endif - /* Count argc for use in a second... */ - for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++); - optind = 1; - debug_printf("running applet %s\n", name); - run_applet_by_name(name, argc_l, child->argv); - } -#endif - debug_printf("exec of %s\n",child->argv[0]); - execvp(child->argv[0],child->argv); - perror_msg("couldn't exec: %s",child->argv[0]); - _exit(1); - } else if (child->group) { - debug_printf("runtime nesting to group\n"); - interactive=0; /* crucial!!!! */ - rcode = run_list_real(child->group); - /* OK to leak memory by not calling free_pipe_list, - * since this process is about to exit */ - _exit(rcode); - } else { - /* Can happen. See what bash does with ">foo" by itself. */ - debug_printf("trying to pseudo_exec null command\n"); - _exit(EXIT_SUCCESS); - } -} - -static void insert_bg_job(struct pipe *pi) -{ - struct pipe *thejob; - - /* Linear search for the ID of the job to use */ - pi->jobid = 1; - for (thejob = job_list; thejob; thejob = thejob->next) - if (thejob->jobid >= pi->jobid) - pi->jobid = thejob->jobid + 1; - - /* add thejob to the list of running jobs */ - if (!job_list) { - thejob = job_list = xmalloc(sizeof(*thejob)); - } else { - for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */; - thejob->next = xmalloc(sizeof(*thejob)); - thejob = thejob->next; - } - - /* physically copy the struct job */ - memcpy(thejob, pi, sizeof(struct pipe)); - thejob->next = NULL; - thejob->running_progs = thejob->num_progs; - thejob->stopped_progs = 0; - thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */ - - //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) - { - char *bar=thejob->text; - char **foo=pi->progs[0].argv; - while(foo && *foo) { - bar += sprintf(bar, "%s ", *foo++); - } - } - - /* we don't wait for background thejobs to return -- append it - to the list of backgrounded thejobs and leave it alone */ - printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid); - last_bg_pid = thejob->progs[0].pid; - last_jobid = thejob->jobid; -} - -/* remove a backgrounded job */ -static void remove_bg_job(struct pipe *pi) -{ - struct pipe *prev_pipe; - - if (pi == job_list) { - job_list = pi->next; - } else { - prev_pipe = job_list; - while (prev_pipe->next != pi) - prev_pipe = prev_pipe->next; - prev_pipe->next = pi->next; - } - if (job_list) - last_jobid = job_list->jobid; - else - last_jobid = 0; - - pi->stopped_progs = 0; - free_pipe(pi, 0); - free(pi); -} - -/* Checks 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; - int prognum = 0; - struct pipe *pi; - pid_t childpid; - - attributes = WUNTRACED; - if (fg_pipe==NULL) { - attributes |= WNOHANG; - } - - while ((childpid = waitpid(-1, &status, attributes)) > 0) { - if (fg_pipe) { - int i, rcode = 0; - for (i=0; i < fg_pipe->num_progs; i++) { - if (fg_pipe->progs[i].pid == childpid) { - if (i==fg_pipe->num_progs-1) - rcode=WEXITSTATUS(status); - (fg_pipe->num_progs)--; - return(rcode); - } - } - } - - for (pi = job_list; pi; pi = pi->next) { - prognum = 0; - while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) { - prognum++; - } - if (prognum < pi->num_progs) - break; - } - - if(pi==NULL) { - debug_printf("checkjobs: pid %d was not in our list!\n", childpid); - continue; - } - - if (WIFEXITED(status) || WIFSIGNALED(status)) { - /* child exited */ - pi->running_progs--; - pi->progs[prognum].pid = 0; - - if (!pi->running_progs) { - printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text); - remove_bg_job(pi); - } - } else { - /* child stopped */ - pi->stopped_progs++; - pi->progs[prognum].is_stopped = 1; - -#if 0 - /* Printing this stuff is a pain, since it tends to - * overwrite the prompt an inconveinient moments. So - * don't do that. */ - if (pi->stopped_progs == pi->num_progs) { - printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text); - } -#endif - } - } - - if (childpid == -1 && errno != ECHILD) - perror_msg("waitpid"); - - /* move the shell to the foreground */ - //if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) - // perror_msg("tcsetpgrp-2"); - return -1; -} - -/* Figure out our controlling tty, checking in order stderr, - * stdin, and stdout. If check_pgrp is set, also check that - * we belong to the foreground process group associated with - * that tty. The value of shell_terminal is needed in order to call - * tcsetpgrp(shell_terminal, ...); */ -void controlling_tty(int check_pgrp) -{ - pid_t curpgrp; - - if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0 - && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0 - && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0) - goto shell_terminal_error; - - if (check_pgrp && curpgrp != getpgid(0)) - goto shell_terminal_error; - - return; - -shell_terminal_error: - shell_terminal = -1; - return; -} - -/* run_pipe_real() starts all the jobs, but doesn'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_real returns, and the exit code is provided as the - * return value. - * - * The input of the pipe is always stdin, the output is always - * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus, - * because it tries to avoid running the command substitution in - * subshell, when that is in fact necessary. The subshell process - * now has its stdout directed to the input of the appropriate pipe, - * so this routine is noticeably simpler. - */ -static int run_pipe_real(struct pipe *pi) -{ - int i; - int nextin, nextout; - int pipefds[2]; /* pipefds[0] is for reading */ - struct child_prog *child; - struct built_in_command *x; - - nextin = 0; - pi->pgrp = -1; - - /* Check if this is a simple builtin (not part of a pipe). - * Builtins within pipes have to fork anyway, and are handled in - * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. - */ - if (pi->num_progs == 1) child = & (pi->progs[0]); - if (pi->num_progs == 1 && child->group && child->subshell == 0) { - int squirrel[] = {-1, -1, -1}; - int rcode; - debug_printf("non-subshell grouping\n"); - setup_redirects(child, squirrel); - /* XXX could we merge code with following builtin case, - * by creating a pseudo builtin that calls run_list_real? */ - rcode = run_list_real(child->group); - restore_redirects(squirrel); - return rcode; - } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) { - for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ } - if (i!=0 && child->argv[i]==NULL) { - /* assignments, but no command: set the local environment */ - for (i=0; child->argv[i]!=NULL; i++) { - - /* Ok, this case is tricky. We have to decide if this is a - * local variable, or an already exported variable. If it is - * already exported, we have to export the new value. If it is - * not exported, we need only set this as a local variable. - * This junk is all to decide whether or not to export this - * variable. */ - int export_me=0; - char *name, *value; - name = xstrdup(child->argv[i]); - debug_printf("Local environment set: %s\n", name); - value = strchr(name, '='); - if (value) - *value=0; - if ( get_local_var(name)) { - export_me=1; - } - free(name); - set_local_var(child->argv[i], export_me); - } - return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */ - } - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[i], x->cmd) == 0 ) { - int squirrel[] = {-1, -1, -1}; - int rcode; - if (x->function == builtin_exec && child->argv[i+1]==NULL) { - debug_printf("magic exec\n"); - setup_redirects(child,NULL); - return EXIT_SUCCESS; - } - debug_printf("builtin inline %s\n", child->argv[0]); - /* XXX 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 with glibc. */ - setup_redirects(child, squirrel); - for (i=0; is_assignment(child->argv[i]); i++) { - putenv(strdup(child->argv[i])); - } - child->argv+=i; /* XXX horrible hack */ - rcode = x->function(child); - child->argv-=i; /* XXX restore hack so free() can work right */ - restore_redirects(squirrel); - return rcode; - } - } - } - - for (i = 0; i < pi->num_progs; i++) { - child = & (pi->progs[i]); - - /* pipes are inserted between pairs of commands */ - if ((i + 1) < pi->num_progs) { - if (pipe(pipefds)<0) perror_msg_and_die("pipe"); - nextout = pipefds[1]; - } else { - nextout=1; - pipefds[0] = -1; - } - - /* XXX test for failed fork()? */ - if (!(child->pid = fork())) { - /* Set the handling for job control signals back to the default. */ - signal(SIGINT, SIG_DFL); - signal(SIGQUIT, SIG_DFL); - signal(SIGTERM, SIG_DFL); - signal(SIGTSTP, SIG_DFL); - signal(SIGTTIN, SIG_DFL); - signal(SIGTTOU, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - - close_all(); - - if (nextin != 0) { - dup2(nextin, 0); - close(nextin); - } - if (nextout != 1) { - dup2(nextout, 1); - close(nextout); - } - if (pipefds[0]!=-1) { - close(pipefds[0]); /* opposite end of our output pipe */ - } - - /* Like bash, explicit redirects override pipes, - * and the pipe fd is available for dup'ing. */ - setup_redirects(child,NULL); - - if (interactive && pi->followup!=PIPE_BG) { - /* If we (the child) win the race, put ourselves in the process - * group whose leader is the first process in this pipe. */ - if (pi->pgrp < 0) { - pi->pgrp = getpid(); - } - if (setpgid(0, pi->pgrp) == 0) { - tcsetpgrp(2, pi->pgrp); - } - } - - pseudo_exec(child); - } - - - /* put our child in the process group whose leader is the - first process in this pipe */ - if (pi->pgrp < 0) { - pi->pgrp = child->pid; - } - /* Don't check for errors. The child may be dead already, - * in which case setpgid returns error code EACCES. */ - setpgid(child->pid, pi->pgrp); - - if (nextin != 0) - close(nextin); - if (nextout != 1) - close(nextout); - - /* If there isn't another process, nextin is garbage - but it doesn't matter */ - nextin = pipefds[0]; - } - return -1; -} - -static int run_list_real(struct pipe *pi) -{ - int rcode=0; - int if_code=0, next_if_code=0; /* need double-buffer to handle elif */ - reserved_style rmode, skip_more_in_this_rmode=RES_XXXX; - for (;pi;pi=pi->next) { - rmode = pi->r_mode; - debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode); - if (rmode == skip_more_in_this_rmode) continue; - skip_more_in_this_rmode = RES_XXXX; - if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code; - if (rmode == RES_THEN && if_code) continue; - if (rmode == RES_ELSE && !if_code) continue; - if (rmode == RES_ELIF && !if_code) continue; - if (pi->num_progs == 0) continue; - rcode = run_pipe_real(pi); - debug_printf("run_pipe_real returned %d\n",rcode); - if (rcode!=-1) { - /* We only ran a builtin: rcode was set by the return value - * of run_pipe_real(), and we don't need to wait for anything. */ - } else if (pi->followup==PIPE_BG) { - /* XXX check bash's behavior with nontrivial pipes */ - /* XXX compute jobid */ - /* XXX what does bash do with attempts to background builtins? */ - insert_bg_job(pi); - rcode = EXIT_SUCCESS; - } else { - if (interactive) { - /* move the new process group into the foreground */ - if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY) - perror_msg("tcsetpgrp-3"); - rcode = checkjobs(pi); - /* move the shell to the foreground */ - if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY) - perror_msg("tcsetpgrp-4"); - } else { - rcode = checkjobs(pi); - } - debug_printf("checkjobs returned %d\n",rcode); - } - last_return_code=rcode; - if ( rmode == RES_IF || rmode == RES_ELIF ) - next_if_code=rcode; /* can be overwritten a number of times */ - if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) || - (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) ) - skip_more_in_this_rmode=rmode; - checkjobs(NULL); - } - return rcode; -} - -/* broken, of course, but OK for testing */ -static char *indenter(int i) -{ - static char blanks[]=" "; - return &blanks[sizeof(blanks)-i-1]; -} - -/* return code is the exit status of the pipe */ -static int free_pipe(struct pipe *pi, int indent) -{ - char **p; - struct child_prog *child; - struct redir_struct *r, *rnext; - int a, i, ret_code=0; - char *ind = indenter(indent); - - if (pi->stopped_progs > 0) - return ret_code; - final_printf("%s run pipe: (pid %d)\n",ind,getpid()); - for (i=0; i<pi->num_progs; i++) { - child = &pi->progs[i]; - final_printf("%s command %d:\n",ind,i); - if (child->argv) { - for (a=0,p=child->argv; *p; a++,p++) { - final_printf("%s argv[%d] = %s\n",ind,a,*p); - } - globfree(&child->glob_result); - child->argv=NULL; - } else if (child->group) { - final_printf("%s begin group (subshell:%d)\n",ind, child->subshell); - ret_code = free_pipe_list(child->group,indent+3); - final_printf("%s end group\n",ind); - } else { - final_printf("%s (nil)\n",ind); - } - for (r=child->redirects; r; r=rnext) { - final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip); - if (r->dup == -1) { - /* guard against the case >$FOO, where foo is unset or blank */ - if (r->word.gl_pathv) { - final_printf(" %s\n", *r->word.gl_pathv); - globfree(&r->word); - } - } else { - final_printf("&%d\n", r->dup); - } - rnext=r->next; - free(r); - } - child->redirects=NULL; - } - free(pi->progs); /* children are an array, they get freed all at once */ - pi->progs=NULL; - 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; - char *ind = indenter(indent); - for (pi=head; pi; pi=next) { - final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode); - rcode = free_pipe(pi, indent); - final_printf("%s pipe followup code %d\n", ind, pi->followup); - next=pi->next; - pi->next=NULL; - free(pi); - } - return rcode; -} - -/* Select which version we will use */ -static int run_list(struct pipe *pi) -{ - int rcode=0; - if (fake_mode==0) { - rcode = run_list_real(pi); - } - /* free_pipe_list has the side effect of clearing memory - * In the long run that function can be merged with run_list_real, - * but doing that now would hobble the debugging effort. */ - free_pipe_list(pi,0); - return rcode; -} - -/* The API for glob is arguably broken. This routine pushes a non-matching - * string into the output structure, removing non-backslashed backslashes. - * If someone can prove me wrong, by performing this function within the - * original glob(3) api, feel free to rewrite this routine into oblivion. - * Return code (0 vs. GLOB_NOSPACE) matches glob(3). - * XXX broken if the last character is '\\', check that before calling. - */ -static int globhack(const char *src, int flags, glob_t *pglob) -{ - int cnt=0, pathc; - const char *s; - char *dest; - for (cnt=1, s=src; s && *s; s++) { - if (*s == '\\') s++; - cnt++; - } - dest = malloc(cnt); - if (!dest) return GLOB_NOSPACE; - if (!(flags & GLOB_APPEND)) { - pglob->gl_pathv=NULL; - pglob->gl_pathc=0; - pglob->gl_offs=0; - pglob->gl_offs=0; - } - pathc = ++pglob->gl_pathc; - pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv)); - if (pglob->gl_pathv == NULL) return GLOB_NOSPACE; - pglob->gl_pathv[pathc-1]=dest; - pglob->gl_pathv[pathc]=NULL; - for (s=src; s && *s; s++, dest++) { - if (*s == '\\') s++; - *dest = *s; - } - *dest='\0'; - return 0; -} - -/* XXX broken if the last character is '\\', check that before calling */ -static int glob_needed(const char *s) -{ - for (; *s; s++) { - if (*s == '\\') s++; - if (strchr("*[?",*s)) return 1; - } - return 0; -} - -#if 0 -static void globprint(glob_t *pglob) -{ - int i; - debug_printf("glob_t at %p:\n", pglob); - debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n", - pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags); - for (i=0; i<pglob->gl_pathc; i++) - debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i, - pglob->gl_pathv[i], pglob->gl_pathv[i]); -} -#endif - -static int xglob(o_string *dest, int flags, glob_t *pglob) -{ - int gr; - - /* short-circuit for null word */ - /* we can code this better when the debug_printf's are gone */ - if (dest->length == 0) { - if (dest->nonnull) { - /* bash man page calls this an "explicit" null */ - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); - } else { - return 0; - } - } else if (glob_needed(dest->data)) { - gr = glob(dest->data, flags, NULL, pglob); - debug_printf("glob returned %d\n",gr); - if (gr == GLOB_NOMATCH) { - /* quote removal, or more accurately, backslash removal */ - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); - } - } else { - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); - } - if (gr == GLOB_NOSPACE) - error_msg_and_die("out of memory during glob"); - if (gr != 0) { /* GLOB_ABORTED ? */ - error_msg("glob(3) error %d",gr); - } - /* globprint(glob_target); */ - return gr; -} - -/* This is used to get/check local shell variables */ -static char *get_local_var(const char *s) -{ - struct variables *cur; - - if (!s) - return NULL; - for (cur = top_vars; cur; cur=cur->next) - if(strcmp(cur->name, s)==0) - return cur->value; - return NULL; -} - -/* This is used to set local shell variables - flg_export==0 if only local (not exporting) variable - flg_export==1 if "new" exporting environ - flg_export>1 if current startup environ (not call putenv()) */ -static int set_local_var(const char *s, int flg_export) -{ - char *name, *value; - int result=0; - struct variables *cur; - - name=strdup(s); - - /* Assume when we enter this function that we are already in - * NAME=VALUE format. So the first order of business is to - * split 's' on the '=' into 'name' and 'value' */ - value = strchr(name, '='); - if (value==0 && ++value==0) { - free(name); - return -1; - } - *value++ = 0; - - for(cur = top_vars; cur; cur = cur->next) { - if(strcmp(cur->name, name)==0) - break; - } - - if(cur) { - if(strcmp(cur->value, value)==0) { - if(flg_export>0 && cur->flg_export==0) - cur->flg_export=flg_export; - else - result++; - } else { - if(cur->flg_read_only) { - error_msg("%s: readonly variable", name); - result = -1; - } else { - if(flg_export>0 || cur->flg_export>1) - cur->flg_export=1; - free(cur->value); - - cur->value = strdup(value); - } - } - } else { - cur = malloc(sizeof(struct variables)); - if(!cur) { - result = -1; - } else { - cur->name = strdup(name); - if(cur->name == 0) { - free(cur); - result = -1; - } else { - struct variables *bottom = top_vars; - cur->value = strdup(value); - cur->next = 0; - cur->flg_export = flg_export; - cur->flg_read_only = 0; - while(bottom->next) bottom=bottom->next; - bottom->next = cur; - } - } - } - - if(result==0 && cur->flg_export==1) { - *(value-1) = '='; - result = putenv(name); - } else { - free(name); - if(result>0) /* equivalent to previous set */ - result = 0; - } - return result; -} - -static void unset_local_var(const char *name) -{ - struct variables *cur; - - if (name) { - for (cur = top_vars; cur; cur=cur->next) { - if(strcmp(cur->name, name)==0) - break; - } - if(cur!=0) { - struct variables *next = top_vars; - if(cur->flg_read_only) { - error_msg("%s: readonly variable", name); - return; - } else { - if(cur->flg_export) - unsetenv(cur->name); - free(cur->name); - free(cur->value); - while (next->next != cur) - next = next->next; - next->next = cur->next; - } - free(cur); - } - } -} - -static int is_assignment(const char *s) -{ - if (s==NULL || !isalpha(*s)) return 0; - ++s; - while(isalnum(*s) || *s=='_') ++s; - return *s=='='; -} - -/* the src parameter allows us to peek forward to a possible &n syntax - * for file descriptor duplication, e.g., "2>&1". - * Return code is 0 normally, 1 if a syntax error is detected in src. - * Resource errors (in xmalloc) cause the process to exit */ -static int setup_redirect(struct p_context *ctx, int fd, redir_type style, - struct in_str *input) -{ - struct child_prog *child=ctx->child; - struct redir_struct *redir = child->redirects; - struct redir_struct *last_redir=NULL; - - /* Create a new redir_struct and drop it onto the end of the linked list */ - while(redir) { - last_redir=redir; - redir=redir->next; - } - redir = xmalloc(sizeof(struct redir_struct)); - redir->next=NULL; - redir->word.gl_pathv=NULL; - if (last_redir) { - last_redir->next=redir; - } else { - child->redirects=redir; - } - - redir->type=style; - redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ; - - debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); - - /* Check for a '2>&1' type redirect */ - redir->dup = redirect_dup_num(input); - if (redir->dup == -2) return 1; /* syntax error */ - if (redir->dup != -1) { - /* 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("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup); - } else { - /* We do _not_ try to open the file that src points to, - * since we need to return and let src be expanded first. - * Set ctx->pending_redirect, so we know what to do at the - * end of the next parsed word. - */ - ctx->pending_redirect = redir; - } - return 0; -} - -struct pipe *new_pipe(void) { - struct pipe *pi; - pi = xmalloc(sizeof(struct pipe)); - pi->num_progs = 0; - pi->progs = NULL; - pi->next = NULL; - pi->followup = 0; /* invalid */ - return pi; -} - -static void initialize_context(struct p_context *ctx) -{ - ctx->pipe=NULL; - ctx->pending_redirect=NULL; - ctx->child=NULL; - ctx->list_head=new_pipe(); - ctx->pipe=ctx->list_head; - ctx->w=RES_NONE; - ctx->stack=NULL; - done_command(ctx); /* creates the memory for working child */ -} - -/* normal return is 0 - * if a reserved word is found, and processed, return 1 - * should handle if, then, elif, else, fi, for, while, until, do, done. - * case, function, and select are obnoxious, save those for later. - */ -int reserved_word(o_string *dest, struct p_context *ctx) -{ - struct reserved_combo { - char *literal; - int code; - long flag; - }; - /* 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 struct reserved_combo reserved_list[] = { - { "if", RES_IF, FLAG_THEN | FLAG_START }, - { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, - { "elif", RES_ELIF, FLAG_THEN }, - { "else", RES_ELSE, FLAG_FI }, - { "fi", RES_FI, FLAG_END }, - { "for", RES_FOR, FLAG_DO | FLAG_START }, - { "while", RES_WHILE, FLAG_DO | FLAG_START }, - { "until", RES_UNTIL, FLAG_DO | FLAG_START }, - { "do", RES_DO, FLAG_DONE }, - { "done", RES_DONE, FLAG_END } - }; - struct reserved_combo *r; - for (r=reserved_list; -#define NRES sizeof(reserved_list)/sizeof(struct reserved_combo) - r<reserved_list+NRES; r++) { - if (strcmp(dest->data, r->literal) == 0) { - debug_printf("found reserved word %s, code %d\n",r->literal,r->code); - if (r->flag & FLAG_START) { - struct p_context *new = xmalloc(sizeof(struct p_context)); - debug_printf("push stack\n"); - *new = *ctx; /* physical copy */ - initialize_context(ctx); - ctx->stack=new; - } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) { - syntax(); - ctx->w = RES_SNTX; - b_reset (dest); - return 1; - } - ctx->w=r->code; - ctx->old_flag = r->flag; - if (ctx->old_flag & FLAG_END) { - struct p_context *old; - debug_printf("pop stack\n"); - old = ctx->stack; - old->child->group = ctx->list_head; - old->child->subshell = 0; - *ctx = *old; /* physical copy */ - free(old); - } - b_reset (dest); - return 1; - } - } - return 0; -} - -/* normal return is 0. - * Syntax or xglob errors return 1. */ -static int done_word(o_string *dest, struct p_context *ctx) -{ - struct child_prog *child=ctx->child; - glob_t *glob_target; - int gr, flags = 0; - - debug_printf("done_word: %s %p\n", dest->data, child); - if (dest->length == 0 && !dest->nonnull) { - debug_printf(" true null, ignored\n"); - return 0; - } - if (ctx->pending_redirect) { - glob_target = &ctx->pending_redirect->word; - } else { - if (child->group) { - syntax(); - return 1; /* syntax error, groups and arglists don't mix */ - } - if (!child->argv) { - debug_printf("checking %s for reserved-ness\n",dest->data); - if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX; - } - glob_target = &child->glob_result; - if (child->argv) flags |= GLOB_APPEND; - } - gr = xglob(dest, flags, glob_target); - if (gr != 0) return 1; - - b_reset(dest); - if (ctx->pending_redirect) { - ctx->pending_redirect=NULL; - if (glob_target->gl_pathc != 1) { - error_msg("ambiguous redirect"); - return 1; - } - } else { - child->argv = glob_target->gl_pathv; - } - return 0; -} - -/* The only possible error here is out of memory, in which case - * xmalloc exits. */ -static int done_command(struct p_context *ctx) -{ - /* The child is really already in the pipe structure, so - * advance the pipe counter and make a new, null child. - * Only real trickiness here is that the uncommitted - * child structure, to which ctx->child points, is not - * counted in pi->num_progs. */ - struct pipe *pi=ctx->pipe; - struct child_prog *prog=ctx->child; - - if (prog && prog->group == NULL - && prog->argv == NULL - && prog->redirects == NULL) { - debug_printf("done_command: skipping null command\n"); - return 0; - } else if (prog) { - pi->num_progs++; - debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs); - } else { - debug_printf("done_command: initializing\n"); - } - pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); - - prog = pi->progs + pi->num_progs; - prog->redirects = NULL; - prog->argv = NULL; - prog->is_stopped = 0; - prog->group = NULL; - prog->glob_result.gl_pathv = NULL; - prog->family = pi; - - ctx->child=prog; - /* but ctx->pipe and ctx->list_head remain unchanged */ - return 0; -} - -static int done_pipe(struct p_context *ctx, pipe_style type) -{ - struct pipe *new_p; - done_command(ctx); /* implicit closure of previous command */ - debug_printf("done_pipe, type %d\n", type); - ctx->pipe->followup = type; - ctx->pipe->r_mode = ctx->w; - new_p=new_pipe(); - ctx->pipe->next = new_p; - ctx->pipe = new_p; - ctx->child = NULL; - done_command(ctx); /* set up new pipe to accept commands */ - return 0; -} - -/* 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. - * returns 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 = b_peek(input); - if (ch != '&') return -1; - - b_getch(input); /* get the & */ - ch=b_peek(input); - if (ch == '-') { - b_getch(input); - return -3; /* "-" represents "close me" */ - } - while (isdigit(ch)) { - d = d*10+(ch-'0'); - ok=1; - b_getch(input); - ch = b_peek(input); - } - if (ok) return d; - - 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 - * 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 - * A -1 output from this program means no valid number was found, so the - * caller should use the appropriate default for this redirection. - */ -static int redirect_opt_num(o_string *o) -{ - int num; - - if (o->length==0) return -1; - for(num=0; num<o->length; num++) { - if (!isdigit(*(o->data+num))) { - return -1; - } - } - /* reuse num (and save an int) */ - num=atoi(o->data); - b_reset(o); - return num; -} - -FILE *generate_stream_from_list(struct pipe *head) -{ - FILE *pf; -#if 1 - int pid, channel[2]; - if (pipe(channel)<0) perror_msg_and_die("pipe"); - pid=fork(); - if (pid<0) { - perror_msg_and_die("fork"); - } else if (pid==0) { - close(channel[0]); - if (channel[1] != 1) { - dup2(channel[1],1); - close(channel[1]); - } -#if 0 -#define SURROGATE "surrogate response" - write(1,SURROGATE,sizeof(SURROGATE)); - _exit(run_list(head)); -#else - _exit(run_list_real(head)); /* leaks memory */ -#endif - } - debug_printf("forked child %d\n",pid); - close(channel[1]); - pf = fdopen(channel[0],"r"); - debug_printf("pipe on FILE *%p\n",pf); -#else - free_pipe_list(head,0); - pf=popen("echo surrogate response","r"); - debug_printf("started fake pipe on FILE *%p\n",pf); -#endif - return pf; -} - -/* this version hacked for testing purposes */ -/* return code is exit status of the process that is run. */ -static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end) -{ - int retcode; - o_string result=NULL_O_STRING; - struct p_context inner; - FILE *p; - struct in_str pipe_str; - initialize_context(&inner); - - /* recursion to generate command */ - retcode = parse_stream(&result, &inner, input, subst_end); - if (retcode != 0) return retcode; /* syntax error or EOF */ - done_word(&result, &inner); - done_pipe(&inner, PIPE_SEQ); - b_free(&result); - - p=generate_stream_from_list(inner.list_head); - if (p==NULL) return 1; - mark_open(fileno(p)); - setup_file_in_str(&pipe_str, p); - - /* now send results of command back into original context */ - retcode = parse_stream(dest, ctx, &pipe_str, '\0'); - /* XXX In case of a syntax error, should we try to kill the child? - * That would be tough to do right, so just read until EOF. */ - if (retcode == 1) { - while (b_getch(&pipe_str)!=EOF) { /* discard */ }; - } - - debug_printf("done reading from pipe, pclose()ing\n"); - /* This is the step that wait()s for the child. Should be pretty - * safe, since we just read an EOF from its stdout. We could try - * to better, by using wait(), and keeping track of background jobs - * at the same time. That would be a lot of work, and contrary - * to the KISS philosophy of this program. */ - mark_closed(fileno(p)); - retcode=pclose(p); - free_pipe_list(inner.list_head,0); - debug_printf("pclosed, retcode=%d\n",retcode); - /* XXX this process fails to trim a single trailing newline */ - return retcode; -} - -static int parse_group(o_string *dest, struct p_context *ctx, - struct in_str *input, int ch) -{ - int rcode, endch=0; - struct p_context sub; - struct child_prog *child = ctx->child; - if (child->argv) { - syntax(); - return 1; /* syntax error, groups and arglists don't mix */ - } - initialize_context(&sub); - switch(ch) { - case '(': endch=')'; child->subshell=1; break; - case '{': endch='}'; break; - default: syntax(); /* really logic error */ - } - rcode=parse_stream(dest,&sub,input,endch); - done_word(dest,&sub); /* finish off the final word in the subcontext */ - done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */ - child->group = sub.list_head; - return rcode; - /* child remains "open", available for possible redirects */ -} - -/* basically useful version until someone wants to get fancier, - * see the bash man page under "Parameter Expansion" */ -static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src) -{ - const char *p=NULL; - if (src->data) { - p = getenv(src->data); - if (!p) - p = get_local_var(src->data); - } - if (p) parse_string(dest, ctx, p); /* recursion */ - b_free(src); -} - -/* return code: 0 for OK, 1 for syntax error */ -static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input) -{ - int i, advance=0; - o_string alt=NULL_O_STRING; - char sep[]=" "; - int ch = input->peek(input); /* first character after the $ */ - debug_printf("handle_dollar: ch=%c\n",ch); - if (isalpha(ch)) { - while(ch=b_peek(input),isalnum(ch) || ch=='_') { - b_getch(input); - b_addchr(&alt,ch); - } - lookup_param(dest, ctx, &alt); - } else if (isdigit(ch)) { - i = ch-'0'; /* XXX is $0 special? */ - if (i<global_argc) { - parse_string(dest, ctx, global_argv[i]); /* recursion */ - } - advance = 1; - } else switch (ch) { - case '$': - b_adduint(dest,getpid()); - advance = 1; - break; - case '!': - if (last_bg_pid > 0) b_adduint(dest, last_bg_pid); - advance = 1; - break; - case '?': - b_adduint(dest,last_return_code); - advance = 1; - break; - case '#': - b_adduint(dest,global_argc ? global_argc-1 : 0); - advance = 1; - break; - case '{': - b_getch(input); - /* XXX maybe someone will try to escape the '}' */ - while(ch=b_getch(input),ch!=EOF && ch!='}') { - b_addchr(&alt,ch); - } - if (ch != '}') { - syntax(); - return 1; - } - lookup_param(dest, ctx, &alt); - break; - case '(': - b_getch(input); - process_command_subs(dest, ctx, input, ')'); - break; - case '*': - sep[0]=ifs[0]; - for (i=1; i<global_argc; i++) { - parse_string(dest, ctx, global_argv[i]); - if (i+1 < global_argc) parse_string(dest, ctx, sep); - } - break; - case '@': - case '-': - case '_': - /* still unhandled, but should be eventually */ - error_msg("unhandled syntax: $%c",ch); - return 1; - break; - default: - b_addqchr(dest,'$',dest->quote); - } - /* Eat the character if the flag was set. If the compiler - * is smart enough, we could substitute "b_getch(input);" - * for all the "advance = 1;" above, and also end up with - * a nice size-optimized program. Hah! That'll be the day. - */ - if (advance) b_getch(input); - return 0; -} - -int parse_string(o_string *dest, struct p_context *ctx, const char *src) -{ - struct in_str foo; - setup_string_in_str(&foo, src); - return parse_stream(dest, ctx, &foo, '\0'); -} - -/* return code is 0 for normal exit, 1 for syntax error */ -int parse_stream(o_string *dest, struct p_context *ctx, - struct in_str *input, int end_trigger) -{ - unsigned int ch, m; - int redir_fd; - redir_type redir_style; - int next; - - /* Only double-quote state is handled in the state variable dest->quote. - * A single-quote triggers a bypass of the main loop until its mate is - * found. When recursing, quote state is passed in via dest->quote. */ - - debug_printf("parse_stream, end_trigger=%d\n",end_trigger); - while ((ch=b_getch(input))!=EOF) { - m = map[ch]; - next = (ch == '\n') ? 0 : b_peek(input); - debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n", - ch,ch,m,dest->quote); - if (m==0 || ((m==1 || m==2) && dest->quote)) { - b_addqchr(dest, ch, dest->quote); - } else { - if (m==2) { /* unquoted IFS */ - done_word(dest, ctx); - /* If we aren't performing a substitution, treat a newline as a - * command separator. */ - if (end_trigger != '\0' && ch=='\n') - done_pipe(ctx,PIPE_SEQ); - } - if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) { - debug_printf("leaving parse_stream (triggered)\n"); - return 0; - } -#if 0 - if (ch=='\n') { - /* Yahoo! Time to run with it! */ - done_pipe(ctx,PIPE_SEQ); - run_list(ctx->list_head); - initialize_context(ctx); - } -#endif - if (m!=2) switch (ch) { - case '#': - if (dest->length == 0 && !dest->quote) { - while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); } - } else { - b_addqchr(dest, ch, dest->quote); - } - break; - case '\\': - if (next == EOF) { - syntax(); - return 1; - } - b_addqchr(dest, '\\', dest->quote); - b_addqchr(dest, b_getch(input), dest->quote); - break; - case '$': - if (handle_dollar(dest, ctx, input)!=0) return 1; - break; - case '\'': - dest->nonnull = 1; - while(ch=b_getch(input),ch!=EOF && ch!='\'') { - b_addchr(dest,ch); - } - if (ch==EOF) { - syntax(); - return 1; - } - break; - case '"': - dest->nonnull = 1; - dest->quote = !dest->quote; - break; - case '`': - process_command_subs(dest, ctx, input, '`'); - break; - case '>': - redir_fd = redirect_opt_num(dest); - done_word(dest, ctx); - redir_style=REDIRECT_OVERWRITE; - if (next == '>') { - redir_style=REDIRECT_APPEND; - b_getch(input); - } else if (next == '(') { - syntax(); /* until we support >(list) Process Substitution */ - return 1; - } - setup_redirect(ctx, redir_fd, redir_style, input); - break; - case '<': - redir_fd = redirect_opt_num(dest); - done_word(dest, ctx); - redir_style=REDIRECT_INPUT; - if (next == '<') { - redir_style=REDIRECT_HEREIS; - b_getch(input); - } else if (next == '>') { - redir_style=REDIRECT_IO; - b_getch(input); - } else if (next == '(') { - syntax(); /* until we support <(list) Process Substitution */ - return 1; - } - setup_redirect(ctx, redir_fd, redir_style, input); - break; - case ';': - done_word(dest, ctx); - done_pipe(ctx,PIPE_SEQ); - break; - case '&': - done_word(dest, ctx); - if (next=='&') { - b_getch(input); - done_pipe(ctx,PIPE_AND); - } else { - done_pipe(ctx,PIPE_BG); - } - break; - case '|': - done_word(dest, ctx); - if (next=='|') { - b_getch(input); - 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); - } - break; - case '(': - case '{': - if (parse_group(dest, ctx, input, ch)!=0) return 1; - break; - case ')': - case '}': - syntax(); /* Proper use of this character caught by end_trigger */ - return 1; - break; - default: - syntax(); /* this is really an internal logic error */ - return 1; - } - } - } - /* complain if quote? No, maybe we just finished a command substitution - * that was quoted. Example: - * $ echo "`cat foo` plus more" - * and we just got the EOF generated by the subshell that ran "cat foo" - * The only real complaint is if we got an EOF when end_trigger != '\0', - * that is, we were really supposed to get end_trigger, and never got - * one before the EOF. Can't use the standard "syntax error" return code, - * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ - debug_printf("leaving parse_stream (EOF)\n"); - if (end_trigger != '\0') return -1; - return 0; -} - -void mapset(const unsigned char *set, int code) -{ - const unsigned char *s; - for (s=set; *s; s++) map[*s] = code; -} - -void update_ifs_map(void) -{ - /* char *ifs and char map[256] are both globals. */ - ifs = getenv("IFS"); - if (ifs == NULL) ifs=" \t\n"; - /* Precompute a list of 'flow through' behavior so it can be treated - * quickly up front. Computation is necessary because of IFS. - * Special case handling of IFS == " \t\n" is not implemented. - * The map[] array only really needs two bits each, and on most machines - * that would be faster because of the reduced L1 cache footprint. - */ - memset(map,0,sizeof(map)); /* most characters flow through always */ - mapset("\\$'\"`", 3); /* never flow through */ - mapset("<>;&|(){}#", 1); /* flow through if quoted */ - mapset(ifs, 2); /* also flow through if quoted */ -} - -/* most recursion does not come through here, the exeception is - * from builtin_source() */ -int parse_stream_outer(struct in_str *inp) -{ - - struct p_context ctx; - o_string temp=NULL_O_STRING; - int rcode; - do { - initialize_context(&ctx); - update_ifs_map(); - inp->promptmode=1; - rcode = parse_stream(&temp, &ctx, inp, '\n'); - done_word(&temp, &ctx); - done_pipe(&ctx,PIPE_SEQ); - run_list(ctx.list_head); - b_free(&temp); - } while (rcode != -1); /* loop on syntax errors, return on EOF */ - return 0; -} - -static int parse_string_outer(const char *s) -{ - struct in_str input; - setup_string_in_str(&input, s); - return parse_stream_outer(&input); -} - -static int parse_file_outer(FILE *f) -{ - int rcode; - struct in_str input; - setup_file_in_str(&input, f); - rcode = parse_stream_outer(&input); - return rcode; -} - -/* Make sure we have a controlling tty. If we get started under a job - * aware app (like bash for example), make sure we are now in charge so - * we don't fight over who gets the foreground */ -static void setup_job_control() -{ - static pid_t shell_pgrp; - /* Loop until we are in the foreground. */ - while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ())) - kill (- shell_pgrp, SIGTTIN); - - /* Ignore interactive and job-control signals. */ - signal(SIGINT, SIG_IGN); - signal(SIGQUIT, SIG_IGN); - signal(SIGTERM, SIG_IGN); - signal(SIGTSTP, SIG_IGN); - signal(SIGTTIN, SIG_IGN); - signal(SIGTTOU, SIG_IGN); - signal(SIGCHLD, SIG_IGN); - - /* Put ourselves in our own process group. */ - setsid(); - shell_pgrp = getpid (); - setpgid (shell_pgrp, shell_pgrp); - - /* Grab control of the terminal. */ - tcsetpgrp(shell_terminal, shell_pgrp); -} - -int hush_main(int argc, char **argv) -{ - int opt; - FILE *input; - char **e = environ; - - /* XXX what should these be while sourcing /etc/profile? */ - global_argc = argc; - global_argv = argv; - - /* (re?) initialize globals. Sometimes hush_main() ends up calling - * hush_main(), therefore we cannot rely on the BSS to zero out this - * stuff. Reset these to 0 every time. */ - ifs = NULL; - /* map[] is taken care of with call to update_ifs_map() */ - fake_mode = 0; - interactive = 0; - close_me_head = NULL; - last_bg_pid = 0; - job_list = NULL; - last_jobid = 0; - - /* Initialize some more globals to non-zero values */ - set_cwd(); -#ifdef BB_FEATURE_COMMAND_EDITING - cmdedit_set_initial_prompt(); -#else - PS1 = NULL; -#endif - PS2 = "> "; - - /* initialize our shell local variables with the values - * currently living in the environment */ - if (e) { - for (; *e; e++) - set_local_var(*e, 2); /* without call putenv() */ - } - - last_return_code=EXIT_SUCCESS; - - - if (argv[0] && argv[0][0] == '-') { - debug_printf("\nsourcing /etc/profile\n"); - if ((input = fopen("/etc/profile", "r")) != NULL) { - mark_open(fileno(input)); - parse_file_outer(input); - mark_closed(fileno(input)); - fclose(input); - } - } - input=stdin; - - while ((opt = getopt(argc, argv, "c:xif")) > 0) { - switch (opt) { - case 'c': - { - global_argv = argv+optind; - global_argc = argc-optind; - opt = parse_string_outer(optarg); - goto final_return; - } - break; - case 'i': - interactive++; - break; - case 'f': - fake_mode++; - break; - default: -#ifndef BB_VER - fprintf(stderr, "Usage: sh [FILE]...\n" - " or: sh -c command [args]...\n\n"); - exit(EXIT_FAILURE); -#else - show_usage(); -#endif - } - } - /* A shell is interactive if the `-i' flag was given, or if all of - * the following conditions are met: - * no -c command - * no arguments remaining or the -s flag given - * standard input is a terminal - * standard output is a terminal - * Refer to Posix.2, the description of the `sh' utility. */ - if (argv[optind]==NULL && input==stdin && - isatty(fileno(stdin)) && isatty(fileno(stdout))) { - interactive++; - } - - debug_printf("\ninteractive=%d\n", interactive); - if (interactive) { - /* Looks like they want an interactive shell */ -#ifndef BB_FEATURE_SH_EXTRA_QUIET - printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n"); - printf( "Enter 'help' for a list of built-in commands.\n\n"); -#endif - setup_job_control(); - } - - if (argv[optind]==NULL) { - opt=parse_file_outer(stdin); - goto final_return; - } - - debug_printf("\nrunning script '%s'\n", argv[optind]); - global_argv = argv+optind; - global_argc = argc-optind; - input = xfopen(argv[optind], "r"); - opt = parse_file_outer(input); - -#ifdef BB_FEATURE_CLEAN_UP - fclose(input); - if (cwd && cwd != unknown) - free((char*)cwd); - { - struct variables *cur, *tmp; - for(cur = top_vars; cur; cur = tmp) { - tmp = cur->next; - if (!cur->flg_read_only) { - free(cur->name); - free(cur->value); - free(cur); - } - } - } -#endif - -final_return: - return(opt?opt:last_return_code); -} |