diff options
Diffstat (limited to 'lash.c')
| -rw-r--r-- | lash.c | 1640 |
1 files changed, 0 insertions, 1640 deletions
@@ -1,1640 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * lash -- the BusyBox Lame-Ass SHell - * - * Copyright (C) 1999,2000,2001 by Lineo, inc. - * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org> - * - * Based in part on ladsh.c by Michael K. Johnson and Erik W. Troan, which is - * under the following liberal license: "We have placed this source code in the - * public domain. Use it in any project, free or commercial." - * - * 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 - * - */ - -/* This shell's parsing engine is officially at a dead-end. - * Future work shell work should be done using hush.c - */ - -//For debugging/development on the shell only... -//#define DEBUG_SHELL - - -#include <stdio.h> -#include <stdlib.h> -#include <ctype.h> -#include <errno.h> -#include <fcntl.h> -#include <signal.h> -#include <string.h> -#include <sys/ioctl.h> -#include <sys/wait.h> -#include <unistd.h> -#include <getopt.h> -#include <termios.h> -#include "busybox.h" -#include "cmdedit.h" - -#ifdef BB_LOCALE_SUPPORT -#include <locale.h> -#endif - -#include <glob.h> -#define expand_t glob_t - - -static const int MAX_READ = 128; /* size of input buffer for `read' builtin */ -#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" - - -enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE, - REDIRECT_APPEND -}; - -static const unsigned int DEFAULT_CONTEXT=0x1; -static const unsigned int IF_TRUE_CONTEXT=0x2; -static const unsigned int IF_FALSE_CONTEXT=0x4; -static const unsigned int THEN_EXP_CONTEXT=0x8; -static const unsigned int ELSE_EXP_CONTEXT=0x10; - - -struct jobset { - struct job *head; /* head of list of running jobs */ - struct job *fg; /* current foreground job */ -}; - -struct redir_struct { - enum redir_type type; /* type of redirection */ - int fd; /* file descriptor being redirected */ - char *filename; /* file to redirect fd to */ -}; - -struct child_prog { - pid_t pid; /* 0 if exited */ - char **argv; /* program name and arguments */ - int num_redirects; /* elements in redirection array */ - struct redir_struct *redirects; /* I/O redirects */ - int is_stopped; /* is the program currently running? */ - struct job *family; /* pointer back to the child's parent job */ -}; - -struct job { - 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 programs in job */ - struct job *next; /* to track background commands */ - int stopped_progs; /* number of programs alive, but stopped */ - unsigned int job_context; /* bitmask defining current context */ - struct jobset *job_list; -}; - -struct built_in_command { - char *cmd; /* name */ - char *descr; /* description */ - int (*function) (struct child_prog *); /* function ptr */ -}; - -struct close_me { - int fd; - struct close_me *next; -}; - -/* function prototypes for builtins */ -static int builtin_cd(struct child_prog *cmd); -static int builtin_exec(struct child_prog *cmd); -static int builtin_exit(struct child_prog *cmd); -static int builtin_fg_bg(struct child_prog *cmd); -static int builtin_help(struct child_prog *cmd); -static int builtin_jobs(struct child_prog *dummy); -static int builtin_pwd(struct child_prog *dummy); -static int builtin_export(struct child_prog *cmd); -static int builtin_source(struct child_prog *cmd); -static int builtin_unset(struct child_prog *cmd); -static int builtin_read(struct child_prog *cmd); - - -/* function prototypes for shell stuff */ -static void mark_open(int fd); -static void mark_closed(int fd); -static void close_all(void); -static void checkjobs(struct jobset *job_list); -static void remove_job(struct jobset *j_list, struct job *job); -static int get_command(FILE * source, char *command); -static int parse_command(char **command_ptr, struct job *job, int *inbg); -static int run_command(struct job *newjob, int inbg, int outpipe[2]); -static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn)); -static int busy_loop(FILE * input); - - -/* Table of built-in functions (these are non-forking builtins, meaning they - * can change global variables in the parent shell process but they will not - * work with pipes and redirects; 'unset foo | whatever' will not work) */ -static struct built_in_command bltins[] = { - {"bg", "Resume a job in the background", builtin_fg_bg}, - {"cd", "Change working directory", builtin_cd}, - {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec}, - {"exit", "Exit from shell()", builtin_exit}, - {"fg", "Bring job into the foreground", builtin_fg_bg}, - {"jobs", "Lists the active jobs", builtin_jobs}, - {"export", "Set environment variable", builtin_export}, - {"unset", "Unset environment variable", builtin_unset}, - {"read", "Input environment variable", builtin_read}, - {".", "Source-in and run commands in a file", builtin_source}, - /* to do: add ulimit */ - {NULL, NULL, NULL} -}; - -/* Table of forking built-in functions (things that fork cannot change global - * variables in the parent process, such as the current working directory) */ -static struct built_in_command bltins_forking[] = { - {"pwd", "Print current directory", builtin_pwd}, - {"help", "List shell built-in commands", builtin_help}, - {NULL, NULL, NULL} -}; - - -static int shell_context; /* Type prompt trigger (PS1 or PS2) */ - - -/* Globals that are static to this file */ -static const char *cwd; -static char *local_pending_command = NULL; -static struct jobset job_list = { NULL, NULL }; -static int argc; -static char **argv; -static struct close_me *close_me_head; -static int last_return_code; -static int last_bg_pid; -static unsigned int last_jobid; -static int shell_terminal; -static pid_t shell_pgrp; -static char *PS1; -static char *PS2 = "> "; - - -#ifdef DEBUG_SHELL -static inline 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 - -/* - Most builtins need access to the struct child_prog that has - their arguments, previously coded as cmd->progs[0]. That coding - can exhibit a bug, if the builtin is not the first command in - a pipeline: "echo foo | exec sort" will attempt to exec foo. - -builtin previous use notes ------- ----------------- --------- -cd cmd->progs[0] -exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins -exit cmd->progs[0] -fg_bg cmd->progs[0], job_list->head, job_list->fg -help 0 -jobs job_list->head -pwd 0 -export cmd->progs[0] -source cmd->progs[0] -unset cmd->progs[0] -read cmd->progs[0] - -I added "struct job *family;" to struct child_prog, -and switched API to builtin_foo(struct child_prog *child); -So cmd->text becomes child->family->text - cmd->job_context becomes child->family->job_context - cmd->progs[0] becomes *child - job_list becomes child->family->job_list - */ - -/* 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: %m\n", newdir); - return EXIT_FAILURE; - } - cwd = xgetcwd((char *)cwd); - if (!cwd) - cwd = unknown; - 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++; - close_all(); - pseudo_exec(child); - /* never returns */ -} - -/* built-in 'exit' handler */ -static int builtin_exit(struct child_prog *child) -{ - if (child->argv[1] == NULL) - exit(EXIT_SUCCESS); - - exit (atoi(child->argv[1])); -} - -/* built-in 'fg' and 'bg' handler */ -static int builtin_fg_bg(struct child_prog *child) -{ - int i, jobnum; - struct job *job=NULL; - - /* If they gave us no args, assume they want the last backgrounded task */ - if (!child->argv[1]) { - for (job = child->family->job_list->head; job; job = job->next) { - if (job->jobid == last_jobid) { - break; - } - } - if (!job) { - 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 (job = child->family->job_list->head; job; job = job->next) { - if (job->jobid == jobnum) { - break; - } - } - if (!job) { - 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, job->pgrp); - - child->family->job_list->fg = job; - } - - /* Restart the processes in the job */ - for (i = 0; i < job->num_progs; i++) - job->progs[i].is_stopped = 0; - - job->stopped_progs = 0; - - if ( (i=kill(- job->pgrp, SIGCONT)) < 0) { - if (i == ESRCH) { - remove_job(&job_list, job); - } else { - perror_msg("kill (SIGCONT)"); - } - } - - 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); - } - for (x = bltins_forking; 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 job *job; - char *status_string; - - for (job = child->family->job_list->head; 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) -{ - cwd = xgetcwd((char *)cwd); - if (!cwd) - cwd = unknown; - puts(cwd); - return EXIT_SUCCESS; -} - -/* built-in 'export VAR=value' handler */ -static int builtin_export(struct child_prog *child) -{ - int res; - char *v = child->argv[1]; - - if (v == NULL) { - char **e; - for (e = environ; *e; e++) { - puts(*e); - } - return 0; - } - res = putenv(v); - if (res) - fprintf(stderr, "export: %m\n"); -#ifdef BB_FEATURE_SH_FANCY_PROMPT - if (strncmp(v, "PS1=", 4)==0) - PS1 = getenv("PS1"); -#endif - -#ifdef BB_LOCALE_SUPPORT - if(strncmp(v, "LC_ALL=", 7)==0) - setlocale(LC_ALL, getenv("LC_ALL")); - if(strncmp(v, "LC_CTYPE=", 9)==0) - setlocale(LC_CTYPE, getenv("LC_CTYPE")); -#endif - - return (res); -} - -/* built-in 'read VAR' handler */ -static int builtin_read(struct child_prog *child) -{ - int res = 0, len, newlen; - char *s; - char string[MAX_READ]; - - if (child->argv[1]) { - /* argument (VAR) given: put "VAR=" into buffer */ - strcpy(string, child->argv[1]); - len = strlen(string); - string[len++] = '='; - string[len] = '\0'; - fgets(&string[len], sizeof(string) - len, stdin); /* read string */ - newlen = strlen(string); - if(newlen > len) - string[--newlen] = '\0'; /* chomp trailing newline */ - /* - ** string should now contain "VAR=<value>" - ** copy it (putenv() won't do that, so we must make sure - ** the string resides in a static buffer!) - */ - res = -1; - if((s = strdup(string))) - res = putenv(s); - if (res) - fprintf(stderr, "read: %m\n"); - } - else - fgets(string, sizeof(string), stdin); - - return (res); -} - -/* Built-in '.' handler (read-in and execute commands from file) */ -static int builtin_source(struct child_prog *child) -{ - FILE *input; - int status; - int fd; - - if (child->argv[1] == NULL) - return EXIT_FAILURE; - - input = fopen(child->argv[1], "r"); - if (!input) { - printf( "Couldn't open file '%s'\n", child->argv[1]); - return EXIT_FAILURE; - } - - fd=fileno(input); - mark_open(fd); - /* Now run the file */ - status = busy_loop(input); - fclose(input); - mark_closed(fd); - return (status); -} - -/* built-in 'unset VAR' handler */ -static int builtin_unset(struct child_prog *child) -{ - if (child->argv[1] == NULL) { - printf( "unset: parameter required.\n"); - return EXIT_FAILURE; - } - unsetenv(child->argv[1]); - return EXIT_SUCCESS; -} - -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, *tmp; - for (c=close_me_head; c; c=tmp) { - close(c->fd); - tmp=c->next; - free(c); - } - close_me_head = NULL; -} - - -/* free up all memory from a job */ -static void free_job(struct job *cmd) -{ - int i; - struct jobset *keep; - - for (i = 0; i < cmd->num_progs; i++) { - free(cmd->progs[i].argv); - if (cmd->progs[i].redirects) - free(cmd->progs[i].redirects); - } - if (cmd->progs) - free(cmd->progs); - if (cmd->text) - free(cmd->text); - if (cmd->cmdbuf) - free(cmd->cmdbuf); - keep = cmd->job_list; - memset(cmd, 0, sizeof(struct job)); - cmd->job_list = keep; -} - -/* remove a job from a jobset */ -static void remove_job(struct jobset *j_list, struct job *job) -{ - struct job *prevjob; - - free_job(job); - if (job == j_list->head) { - j_list->head = job->next; - } else { - prevjob = j_list->head; - while (prevjob->next != job) - prevjob = prevjob->next; - prevjob->next = job->next; - } - - if (j_list->head) - last_jobid = j_list->head->jobid; - else - last_jobid = 0; - - free(job); -} - -/* Checks to see if any background processes have exited -- if they - have, figure out why and see if a job has completed */ -static void checkjobs(struct jobset *j_list) -{ - struct job *job; - pid_t childpid; - int status; - int prognum = 0; - - while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) { - for (job = j_list->head; job; job = job->next) { - prognum = 0; - while (prognum < job->num_progs && - job->progs[prognum].pid != childpid) prognum++; - if (prognum < job->num_progs) - break; - } - - /* This happens on backticked commands */ - if(job==NULL) - return; - - if (WIFEXITED(status) || WIFSIGNALED(status)) { - /* child exited */ - job->running_progs--; - job->progs[prognum].pid = 0; - - if (!job->running_progs) { - printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text); - last_jobid=0; - remove_job(j_list, job); - } - } else { - /* child stopped */ - job->stopped_progs++; - job->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 (job->stopped_progs == job->num_progs) { - printf(JOB_STATUS_FORMAT, job->jobid, "Stopped", - job->text); - } -#endif - } - } - - if (childpid == -1 && errno != ECHILD) - perror_msg("waitpid"); -} - -/* 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 i; - int openfd; - int mode = O_RDONLY; - struct redir_struct *redir = prog->redirects; - - for (i = 0; i < prog->num_redirects; i++, redir++) { - switch (redir->type) { - case REDIRECT_INPUT: - mode = O_RDONLY; - break; - case REDIRECT_OVERWRITE: - mode = O_WRONLY | O_CREAT | O_TRUNC; - break; - case REDIRECT_APPEND: - mode = O_WRONLY | O_CREAT | O_APPEND; - break; - } - - openfd = open(redir->filename, 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->filename); - return 1; - } - - if (openfd != redir->fd) { - if (squirrel && redir->fd < 3) { - squirrel[redir->fd] = dup(redir->fd); - } - dup2(openfd, redir->fd); - 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); - } - } -} - -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(char **prompt_str) -{ -#ifndef BB_FEATURE_SH_FANCY_PROMPT - /* Set up the prompt */ - if (shell_context == 0) { - 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 = (shell_context==0)? PS1 : PS2; -#endif -} - -static int get_command(FILE * source, char *command) -{ - char *prompt_str; - - if (source == NULL) { - if (local_pending_command) { - /* a command specified (-c option): return it & mark it done */ - strcpy(command, local_pending_command); - free(local_pending_command); - local_pending_command = NULL; - return 0; - } - return 1; - } - - if (source == stdin) { - setup_prompt_string(&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, command); - return 0; -#else - fputs(prompt_str, stdout); -#endif - } - - if (!fgets(command, BUFSIZ - 2, source)) { - if (source == stdin) - printf("\n"); - return 1; - } - - return 0; -} - -static char* itoa(register int i) -{ - static char a[7]; /* Max 7 ints */ - register char *b = a + sizeof(a) - 1; - int sign = (i < 0); - - if (sign) - i = -i; - *b = 0; - do - { - *--b = '0' + (i % 10); - i /= 10; - } - while (i); - if (sign) - *--b = '-'; - return b; -} - -char * strsep_space( char *string, int * ix) -{ - char *token, *begin; - - begin = string; - - /* Short circuit the trivial case */ - if ( !string || ! string[*ix]) - return NULL; - - /* Find the end of the token. */ - while( string && string[*ix] && !isspace(string[*ix]) ) { - (*ix)++; - } - - /* Find the end of any whitespace trailing behind - * the token and let that be part of the token */ - while( string && string[*ix] && isspace(string[*ix]) ) { - (*ix)++; - } - - if (! string && *ix==0) { - /* Nothing useful was found */ - return NULL; - } - - token = xmalloc(*ix+1); - token[*ix] = '\0'; - strncpy(token, string, *ix); - - return token; -} - -static int expand_arguments(char *command) -{ - int total_length=0, length, i, retval, ix = 0; - expand_t expand_result; - char *tmpcmd, *cmd, *cmd_copy; - char *src, *dst, *var; - const char *out_of_space = "out of space during expansion"; - int flags = GLOB_NOCHECK -#ifdef GLOB_BRACE - | GLOB_BRACE -#endif -#ifdef GLOB_TILDE - | GLOB_TILDE -#endif - ; - - /* get rid of the terminating \n */ - chomp(command); - - /* Fix up escape sequences to be the Real Thing(tm) */ - while( command && command[ix]) { - if (command[ix] == '\\') { - const char *tmp = command+ix+1; - command[ix] = process_escape_sequence( &tmp ); - memmove(command+ix + 1, tmp, strlen(tmp)+1); - } - ix++; - } - /* Use glob and then fixup environment variables and such */ - - /* It turns out that glob is very stupid. We have to feed it one word at a - * time since it can't cope with a full string. Here we convert command - * (char*) into cmd (char**, one word per string) */ - - /* We need a clean copy, so strsep can mess up the copy while - * we write stuff into the original (in a minute) */ - cmd = cmd_copy = strdup(command); - *command = '\0'; - for (ix = 0, tmpcmd = cmd; - (tmpcmd = strsep_space(cmd, &ix)) != NULL; cmd += ix, ix=0) { - if (*tmpcmd == '\0') - break; - /* we need to trim() the result for glob! */ - trim(tmpcmd); - retval = glob(tmpcmd, flags, NULL, &expand_result); - free(tmpcmd); /* Free mem allocated by strsep_space */ - if (retval == GLOB_NOSPACE) { - /* Mem may have been allocated... */ - globfree (&expand_result); - error_msg(out_of_space); - return FALSE; - } else if (retval != 0) { - /* Some other error. GLOB_NOMATCH shouldn't - * happen because of the GLOB_NOCHECK flag in - * the glob call. */ - error_msg("syntax error"); - return FALSE; - } else { - /* Convert from char** (one word per string) to a simple char*, - * but don't overflow command which is BUFSIZ in length */ - for (i=0; i < expand_result.gl_pathc; i++) { - length=strlen(expand_result.gl_pathv[i]); - if (total_length+length+1 >= BUFSIZ) { - error_msg(out_of_space); - return FALSE; - } - strcat(command+total_length, " "); - total_length+=1; - strcat(command+total_length, expand_result.gl_pathv[i]); - total_length+=length; - } - globfree (&expand_result); - } - } - free(cmd_copy); - trim(command); - - /* Now do the shell variable substitutions which - * wordexp can't do for us, namely $? and $! */ - src = command; - while((dst = strchr(src,'$')) != NULL){ - var = NULL; - switch(*(dst+1)) { - case '?': - var = itoa(last_return_code); - break; - case '!': - if (last_bg_pid==-1) - *(var)='\0'; - else - var = itoa(last_bg_pid); - break; - /* Everything else like $$, $#, $[0-9], etc. should all be - * expanded by wordexp(), so we can in theory skip that stuff - * here, but just to be on the safe side (i.e., since uClibc - * wordexp doesn't do this stuff yet), lets leave it in for - * now. */ - case '$': - var = itoa(getpid()); - break; - case '#': - var = itoa(argc-1); - break; - case '0':case '1':case '2':case '3':case '4': - case '5':case '6':case '7':case '8':case '9': - { - int ixx=*(dst + 1)-48; - if (ixx >= argc) { - var='\0'; - } else { - var = argv[ixx]; - } - } - break; - - } - if (var) { - /* a single character construction was found, and - * already handled in the case statement */ - src=dst+2; - } else { - /* Looks like an environment variable */ - char delim_hold; - int num_skip_chars=0; - int dstlen = strlen(dst); - /* Is this a ${foo} type variable? */ - if (dstlen >=2 && *(dst+1) == '{') { - src=strchr(dst+1, '}'); - num_skip_chars=1; - } else { - src=dst+1; - while(isalnum(*src) || *src=='_') src++; - } - if (src == NULL) { - src = dst+dstlen; - } - delim_hold=*src; - *src='\0'; /* temporary */ - var = getenv(dst + 1 + num_skip_chars); - *src=delim_hold; - src += num_skip_chars; - } - if (var == NULL) { - /* Seems we got an un-expandable variable. So delete it. */ - var = ""; - } - { - int subst_len = strlen(var); - int trail_len = strlen(src); - if (dst+subst_len+trail_len >= command+BUFSIZ) { - error_msg(out_of_space); - return FALSE; - } - /* Move stuff to the end of the string to accommodate - * filling the created gap with the new stuff */ - memmove(dst+subst_len, src, trail_len+1); - /* Now copy in the new stuff */ - memcpy(dst, var, subst_len); - src = dst+subst_len; - } - } - - return TRUE; -} - -/* Return cmd->num_progs as 0 if no command is present (e.g. an empty - line). If a valid command is found, command_ptr is set to point to - the beginning of the next command (if the original command had more - then one job associated with it) or NULL if no more commands are - present. */ -static int parse_command(char **command_ptr, struct job *job, int *inbg) -{ - char *command; - char *return_command = NULL; - char *src, *buf, *chptr; - int argc_l = 0; - int done = 0; - int argv_alloced; - int i, saw_quote = 0; - char quote = '\0'; - int count; - struct child_prog *prog; - - /* skip leading white space */ - while (**command_ptr && isspace(**command_ptr)) - (*command_ptr)++; - - /* this handles empty lines or leading '#' characters */ - if (!**command_ptr || (**command_ptr == '#')) { - job->num_progs=0; - return 0; - } - - *inbg = 0; - job->num_progs = 1; - job->progs = xmalloc(sizeof(*job->progs)); - - /* We set the argv elements to point inside of this string. The - memory is freed by free_job(). Allocate twice the original - length in case we need to quote every single character. - - Getting clean memory relieves us of the task of NULL - terminating things and makes the rest of this look a bit - cleaner (though it is, admittedly, a tad less efficient) */ - job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char)); - job->text = NULL; - - prog = job->progs; - prog->num_redirects = 0; - prog->redirects = NULL; - prog->is_stopped = 0; - prog->family = job; - - argv_alloced = 5; - prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced); - prog->argv[0] = job->cmdbuf; - - buf = command; - src = *command_ptr; - while (*src && !done) { - if (quote == *src) { - quote = '\0'; - } else if (quote) { - if (*src == '\\') { - src++; - if (!*src) { - error_msg("character expected after \\"); - free_job(job); - return 1; - } - - /* in shell, "\'" should yield \' */ - if (*src != quote) { - *buf++ = '\\'; - *buf++ = '\\'; - } - } else if (*src == '*' || *src == '?' || *src == '[' || - *src == ']') *buf++ = '\\'; - *buf++ = *src; - } else if (isspace(*src)) { - if (*prog->argv[argc_l] || saw_quote) { - buf++, argc_l++; - /* +1 here leaves room for the NULL which ends argv */ - if ((argc_l + 1) == argv_alloced) { - argv_alloced += 5; - prog->argv = xrealloc(prog->argv, - sizeof(*prog->argv) * - argv_alloced); - } - prog->argv[argc_l] = buf; - saw_quote = 0; - } - } else - switch (*src) { - case '"': - case '\'': - quote = *src; - saw_quote = 1; - break; - - case '#': /* comment */ - if (*(src-1)== '$') - *buf++ = *src; - else - done = 1; - break; - - case '>': /* redirects */ - case '<': - i = prog->num_redirects++; - prog->redirects = xrealloc(prog->redirects, - sizeof(*prog->redirects) * - (i + 1)); - - prog->redirects[i].fd = -1; - if (buf != prog->argv[argc_l]) { - /* the stuff before this character may be the file number - being redirected */ - prog->redirects[i].fd = - strtol(prog->argv[argc_l], &chptr, 10); - - if (*chptr && *prog->argv[argc_l]) { - buf++, argc_l++; - prog->argv[argc_l] = buf; - } - } - - if (prog->redirects[i].fd == -1) { - if (*src == '>') - prog->redirects[i].fd = 1; - else - prog->redirects[i].fd = 0; - } - - if (*src++ == '>') { - if (*src == '>') - prog->redirects[i].type = - REDIRECT_APPEND, src++; - else - prog->redirects[i].type = REDIRECT_OVERWRITE; - } else { - prog->redirects[i].type = REDIRECT_INPUT; - } - - /* This isn't POSIX sh compliant. Oh well. */ - chptr = src; - while (isspace(*chptr)) - chptr++; - - if (!*chptr) { - error_msg("file name expected after %c", *(src-1)); - free_job(job); - job->num_progs=0; - return 1; - } - - prog->redirects[i].filename = buf; - while (*chptr && !isspace(*chptr)) - *buf++ = *chptr++; - - src = chptr - 1; /* we src++ later */ - prog->argv[argc_l] = ++buf; - break; - - case '|': /* pipe */ - /* finish this command */ - if (*prog->argv[argc_l] || saw_quote) - argc_l++; - if (!argc_l) { - error_msg("empty command in pipe"); - free_job(job); - job->num_progs=0; - return 1; - } - prog->argv[argc_l] = NULL; - - /* and start the next */ - job->num_progs++; - job->progs = xrealloc(job->progs, - sizeof(*job->progs) * job->num_progs); - prog = job->progs + (job->num_progs - 1); - prog->num_redirects = 0; - prog->redirects = NULL; - prog->is_stopped = 0; - prog->family = job; - argc_l = 0; - - argv_alloced = 5; - prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced); - prog->argv[0] = ++buf; - - src++; - while (*src && isspace(*src)) - src++; - - if (!*src) { - error_msg("empty command in pipe"); - free_job(job); - job->num_progs=0; - return 1; - } - src--; /* we'll ++ it at the end of the loop */ - - break; - - case '&': /* background */ - *inbg = 1; - case ';': /* multiple commands */ - done = 1; - return_command = *command_ptr + (src - *command_ptr) + 1; - break; - - case '\\': - src++; - if (!*src) { - error_msg("character expected after \\"); - free_job(job); - return 1; - } - if (*src == '*' || *src == '[' || *src == ']' - || *src == '?') *buf++ = '\\'; - /* fallthrough */ - default: - *buf++ = *src; - } - - src++; - } - - if (*prog->argv[argc_l] || saw_quote) { - argc_l++; - } - if (!argc_l) { - free_job(job); - return 0; - } - prog->argv[argc_l] = NULL; - - if (!return_command) { - job->text = xmalloc(strlen(*command_ptr) + 1); - strcpy(job->text, *command_ptr); - } else { - /* This leaves any trailing spaces, which is a bit sloppy */ - count = return_command - *command_ptr; - job->text = xmalloc(count + 1); - strncpy(job->text, *command_ptr, count); - job->text[count] = '\0'; - } - - *command_ptr = return_command; - - return 0; -} - -/* Run the child_prog, no matter what kind of command it uses. - */ -static int pseudo_exec(struct child_prog *child) -{ - struct built_in_command *x; -#ifdef BB_FEATURE_SH_STANDALONE_SHELL - char *name; -#endif - - /* Check if the command matches any of the non-forking 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 ) { - exit(x->function(child)); - } - } - - /* Check if the command matches any of the forking builtins. */ - for (x = bltins_forking; x->cmd; x++) { - if (strcmp(child->argv[0], x->cmd) == 0) { - applet_name=x->cmd; - exit (x->function(child)); - } - } -#ifdef BB_FEATURE_SH_STANDALONE_SHELL - /* Check if the command matches any busybox internal - * commands ("applets") here. Following discussions from - * November 2000 on busybox@opensource.lineo.com, don't use - * get_last_path_component(). This way explicit (with - * slashes) filenames will never be interpreted as an - * applet, just like with builtins. This way the user can - * override an applet with an explicit filename reference. - * The only downside to this change is that an explicit - * /bin/foo invocation will fork and exec /bin/foo, even if - * /bin/foo is a symlink to busybox. - */ - name = child->argv[0]; - -#ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN - /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then - * if you run /bin/cat, it will use BusyBox cat even if - * /bin/cat exists on the filesystem and is _not_ busybox. - * Some systems want this, others do not. Choose wisely. :-) - */ - name = get_last_path_component(name); -#endif - - { - char** argv_l=child->argv; - int argc_l; - for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++); - optind = 1; - run_applet_by_name(name, argc_l, child->argv); - } -#endif - - execvp(child->argv[0], child->argv); - perror_msg_and_die("%s", child->argv[0]); -} - -static void insert_job(struct job *newjob, int inbg) -{ - struct job *thejob; - struct jobset *j_list=newjob->job_list; - - /* find the ID for thejob to use */ - newjob->jobid = 1; - for (thejob = j_list->head; thejob; thejob = thejob->next) - if (thejob->jobid >= newjob->jobid) - newjob->jobid = thejob->jobid + 1; - - /* add thejob to the list of running jobs */ - if (!j_list->head) { - thejob = j_list->head = xmalloc(sizeof(*thejob)); - } else { - for (thejob = j_list->head; thejob->next; thejob = thejob->next) /* nothing */; - thejob->next = xmalloc(sizeof(*thejob)); - thejob = thejob->next; - } - - *thejob = *newjob; /* physically copy the struct job */ - thejob->next = NULL; - thejob->running_progs = thejob->num_progs; - thejob->stopped_progs = 0; - - if (inbg) { - /* 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, - newjob->progs[newjob->num_progs - 1].pid); - last_jobid = newjob->jobid; - last_bg_pid=newjob->progs[newjob->num_progs - 1].pid; - } else { - newjob->job_list->fg = thejob; - - /* move the new process group into the foreground */ - /* suppress messages when run from /linuxrc mag@sysgo.de */ - if (tcsetpgrp(shell_terminal, newjob->pgrp) && errno != ENOTTY) - perror_msg("tcsetpgrp"); - } -} - -static int run_command(struct job *newjob, int inbg, int outpipe[2]) -{ - /* struct job *thejob; */ - int i; - int nextin, nextout; - int pipefds[2]; /* pipefd[0] is for reading */ - struct built_in_command *x; - struct child_prog *child; - - nextin = 0, nextout = 1; - for (i = 0; i < newjob->num_progs; i++) { - child = & (newjob->progs[i]); - - if ((i + 1) < newjob->num_progs) { - if (pipe(pipefds)<0) perror_msg_and_die("pipe"); - nextout = pipefds[1]; - } else { - if (outpipe[1]!=-1) { - nextout = outpipe[1]; - } else { - nextout = 1; - } - } - - - /* Check if the command matches any non-forking builtins, - * but only if this is a simple command. - * Non-forking builtins within pipes have to fork anyway, - * and are handled in pseudo_exec. "echo foo | read bar" - * is doomed to failure, and doesn't work on bash, either. - */ - if (newjob->num_progs == 1) { - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[0], x->cmd) == 0 ) { - int squirrel[] = {-1, -1, -1}; - int rcode; - setup_redirects(child, squirrel); - rcode = x->function(child); - restore_redirects(squirrel); - return rcode; - } - } - } - - if (!(child->pid = fork())) { - /* Set the handling for job control signals back to the default. */ - signal(SIGINT, SIG_DFL); - signal(SIGQUIT, SIG_DFL); - signal(SIGTSTP, SIG_DFL); - signal(SIGTTIN, SIG_DFL); - signal(SIGTTOU, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - - close_all(); - - if (outpipe[1]!=-1) { - close(outpipe[0]); - } - if (nextin != 0) { - dup2(nextin, 0); - close(nextin); - } - - if (nextout != 1) { - dup2(nextout, 1); - dup2(nextout, 2); /* Really? */ - close(nextout); - close(pipefds[0]); - } - - /* explicit redirects override pipes */ - setup_redirects(child,NULL); - - pseudo_exec(child); - } - if (outpipe[1]!=-1) { - close(outpipe[1]); - } - - /* put our child in the process group whose leader is the - first process in this pipe */ - setpgid(child->pid, newjob->progs[0].pid); - 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]; - } - - newjob->pgrp = newjob->progs[0].pid; - - insert_job(newjob, inbg); - - return 0; -} - -static int busy_loop(FILE * input) -{ - char *command; - char *next_command = NULL; - struct job newjob; - pid_t parent_pgrp; - int i; - int inbg; - int status; - newjob.job_list = &job_list; - newjob.job_context = DEFAULT_CONTEXT; - - /* save current owner of TTY so we can restore it on exit */ - parent_pgrp = tcgetpgrp(shell_terminal); - - command = (char *) xcalloc(BUFSIZ, sizeof(char)); - - while (1) { - if (!job_list.fg) { - /* no job is in the foreground */ - - /* see if any background processes have exited */ - checkjobs(&job_list); - - if (!next_command) { - if (get_command(input, command)) - break; - next_command = command; - } - - if (expand_arguments(next_command) == FALSE) { - free(command); - command = (char *) xcalloc(BUFSIZ, sizeof(char)); - next_command = NULL; - continue; - } - - if (!parse_command(&next_command, &newjob, &inbg) && - newjob.num_progs) { - int pipefds[2] = {-1,-1}; - debug_printf( "job=%p fed to run_command by busy_loop()'\n", - &newjob); - run_command(&newjob, inbg, pipefds); - } - else { - free(command); - command = (char *) xcalloc(BUFSIZ, sizeof(char)); - next_command = NULL; - } - } else { - /* a job is running in the foreground; wait for it */ - i = 0; - while (!job_list.fg->progs[i].pid || - job_list.fg->progs[i].is_stopped == 1) i++; - - if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0) - perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid); - - if (WIFEXITED(status) || WIFSIGNALED(status)) { - /* the child exited */ - job_list.fg->running_progs--; - job_list.fg->progs[i].pid = 0; - - last_return_code=WEXITSTATUS(status); - - if (!job_list.fg->running_progs) { - /* child exited */ - remove_job(&job_list, job_list.fg); - job_list.fg = NULL; - } - } else { - /* the child was stopped */ - job_list.fg->stopped_progs++; - job_list.fg->progs[i].is_stopped = 1; - - if (job_list.fg->stopped_progs == job_list.fg->running_progs) { - printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid, - "Stopped", job_list.fg->text); - job_list.fg = NULL; - } - } - - if (!job_list.fg) { - /* move the shell to the foreground */ - /* suppress messages when run from /linuxrc mag@sysgo.de */ - if (tcsetpgrp(shell_terminal, getpgrp()) && errno != ENOTTY) - perror_msg("tcsetpgrp"); - } - } - } - free(command); - - /* return controlling TTY back to parent process group before exiting */ - if (tcsetpgrp(shell_terminal, parent_pgrp)) - perror_msg("tcsetpgrp"); - - /* return exit status if called with "-c" */ - if (input == NULL && WIFEXITED(status)) - return WEXITSTATUS(status); - - return 0; -} - - -#ifdef BB_FEATURE_CLEAN_UP -void free_memory(void) -{ - if (cwd && cwd!=unknown) { - free((char*)cwd); - } - if (local_pending_command) - free(local_pending_command); - - if (job_list.fg && !job_list.fg->running_progs) { - remove_job(&job_list, job_list.fg); - } -} -#endif - -/* 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() -{ - int status; - - /* Loop until we are in the foreground. */ - while ((status = tcgetpgrp (shell_terminal)) >= 0) { - if (status == (shell_pgrp = getpgrp ())) { - break; - } - kill (- shell_pgrp, SIGTTIN); - } - - /* Ignore interactive and job-control signals. */ - signal(SIGINT, SIG_IGN); - signal(SIGQUIT, 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 lash_main(int argc_l, char **argv_l) -{ - int opt, interactive=FALSE; - FILE *input = stdin; - argc = argc_l; - argv = argv_l; - - /* These variables need re-initializing when recursing */ - last_jobid = 0; - local_pending_command = NULL; - close_me_head = NULL; - job_list.head = NULL; - job_list.fg = NULL; - last_return_code=1; - - if (argv[0] && argv[0][0] == '-') { - FILE *prof_input; - prof_input = fopen("/etc/profile", "r"); - if (prof_input) { - int tmp_fd = fileno(prof_input); - mark_open(tmp_fd); - /* Now run the file */ - busy_loop(prof_input); - fclose(prof_input); - mark_closed(tmp_fd); - } - } - - while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) { - switch (opt) { - case 'c': - input = NULL; - if (local_pending_command != 0) - error_msg_and_die("multiple -c arguments"); - local_pending_command = xstrdup(argv[optind]); - optind++; - argv = argv+optind; - break; - case 'i': - interactive = TRUE; - break; - default: - show_usage(); - } - } - /* 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=TRUE; - } - setup_job_control(); - if (interactive==TRUE) { - //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]); - /* Looks like they want an interactive shell */ -#ifndef BB_FEATURE_SH_EXTRA_QUIET - printf( "\n\n" BB_BANNER " Built-in shell (lash)\n"); - printf( "Enter 'help' for a list of built-in commands.\n\n"); -#endif - } else if (local_pending_command==NULL) { - //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]); - input = xfopen(argv[optind], "r"); - mark_open(fileno(input)); /* be lazy, never mark this closed */ - } - - /* initialize the cwd -- this is never freed...*/ - cwd = xgetcwd(0); - if (!cwd) - cwd = unknown; - -#ifdef BB_FEATURE_CLEAN_UP - atexit(free_memory); -#endif - -#ifdef BB_FEATURE_COMMAND_EDITING - cmdedit_set_initial_prompt(); -#else - PS1 = NULL; -#endif - - return (busy_loop(input)); -} |