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authorDenis Vlasenko2007-11-23 23:28:55 +0000
committerDenis Vlasenko2007-11-23 23:28:55 +0000
commit96702ca945a8deac1f989584f2b25d1a16d14b72 (patch)
tree4de934d94214ca3b46dbce6de8dabe4517bd5247 /shell/lash_unused.c
parent8ec6ee47f1e70ff25518ad6455e68d45d7ce1b87 (diff)
downloadbusybox-96702ca945a8deac1f989584f2b25d1a16d14b72.zip
busybox-96702ca945a8deac1f989584f2b25d1a16d14b72.tar.gz
kill lash. "lash" builtin still exists, but it runs hush.
Diffstat (limited to 'shell/lash_unused.c')
-rw-r--r--shell/lash_unused.c1570
1 files changed, 1570 insertions, 0 deletions
diff --git a/shell/lash_unused.c b/shell/lash_unused.c
new file mode 100644
index 0000000..781dfdb
--- /dev/null
+++ b/shell/lash_unused.c
@@ -0,0 +1,1570 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * lash -- the BusyBox Lame-Ass SHell
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.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."
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+
+/* This shell's parsing engine is officially at a dead-end. Future
+ * work shell work should be done using hush, msh, or ash. This is
+ * still a very useful, small shell -- it just don't need any more
+ * features beyond what it already has...
+ */
+
+//For debugging/development on the shell only...
+//#define DEBUG_SHELL
+
+#include <getopt.h>
+#include <glob.h>
+
+#include "busybox.h" /* for struct bb_applet */
+
+#define expand_t glob_t
+
+/* Always enable for the moment... */
+#define CONFIG_LASH_PIPE_N_REDIRECTS
+#define CONFIG_LASH_JOB_CONTROL
+#define ENABLE_LASH_PIPE_N_REDIRECTS 1
+#define ENABLE_LASH_JOB_CONTROL 1
+
+
+enum { MAX_READ = 128 }; /* size of input buffer for 'read' builtin */
+#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
+
+
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
+ REDIRECT_APPEND
+};
+#endif
+
+enum {
+ DEFAULT_CONTEXT = 0x1,
+ IF_TRUE_CONTEXT = 0x2,
+ IF_FALSE_CONTEXT = 0x4,
+ THEN_EXP_CONTEXT = 0x8,
+ ELSE_EXP_CONTEXT = 0x10
+};
+
+#define LASH_OPT_DONE (1)
+#define LASH_OPT_SAW_QUOTE (2)
+
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+struct redir_struct {
+ enum redir_type type; /* type of redirection */
+ int fd; /* file descriptor being redirected */
+ char *filename; /* file to redirect fd to */
+};
+#endif
+
+struct child_prog {
+ pid_t pid; /* 0 if exited */
+ char **argv; /* program name and arguments */
+ int num_redirects; /* elements in redirection array */
+ int is_stopped; /* is the program currently running? */
+ struct job *family; /* pointer back to the child's parent job */
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+ struct redir_struct *redirects; /* I/O redirects */
+#endif
+};
+
+struct jobset {
+ struct job *head; /* head of list of running jobs */
+ struct job *fg; /* current foreground 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 {
+ const char *cmd; /* name */
+ const char *descr; /* description */
+ int (*function) (struct child_prog *); /* function ptr */
+};
+
+/* 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 checkjobs(struct jobset *job_list);
+static void remove_job(struct jobset *j_list, struct job *job);
+static int get_command_bufsiz(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 const 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},
+ /* These were "forked applets", but distinction was nuked */
+ /* Original comment retained: */
+ /* Table of forking built-in functions (things that fork cannot change global
+ * variables in the parent process, such as the current working directory) */
+ {"pwd" , "Print current directory", builtin_pwd},
+ {"help" , "List shell built-in commands", builtin_help},
+ /* to do: add ulimit */
+};
+
+
+#define VEC_LAST(v) v[ARRAY_SIZE(v)-1]
+
+
+static int shell_context; /* Type prompt trigger (PS1 or PS2) */
+
+
+/* Globals that are static to this file */
+static char *cwd;
+static char *local_pending_command;
+static struct jobset job_list = { NULL, NULL };
+static int global_argc;
+static char **global_argv;
+static llist_t *close_me_list;
+static int last_return_code;
+static int last_bg_pid;
+static unsigned int last_jobid;
+static int shell_terminal;
+static const char *PS1;
+static const 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 ATTRIBUTE_UNUSED *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
+ */
+
+
+static void update_cwd(void)
+{
+ cwd = xrealloc_getcwd_or_warn(cwd);
+ if (!cwd)
+ cwd = xstrdup(bb_msg_unknown);
+}
+
+/* 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)) {
+ bb_perror_msg("cd: %s", newdir);
+ return EXIT_FAILURE;
+ }
+ update_cwd();
+ 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++;
+ while (close_me_list)
+ close((long)llist_pop(&close_me_list));
+ 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;
+
+ /* 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) {
+ goto found;
+ }
+ }
+ bb_error_msg("%s: no current job", child->argv[0]);
+ return EXIT_FAILURE;
+ }
+ if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
+ bb_error_msg(bb_msg_invalid_arg, child->argv[1], child->argv[0]);
+ return EXIT_FAILURE;
+ }
+ for (job = child->family->job_list->head; job; job = job->next) {
+ if (job->jobid == jobnum) {
+ goto found;
+ }
+ }
+ bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
+ return EXIT_FAILURE;
+ found:
+ 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;
+
+ i = kill(- job->pgrp, SIGCONT);
+ if (i < 0) {
+ if (errno == ESRCH) {
+ remove_job(&job_list, job);
+ } else {
+ bb_perror_msg("kill (SIGCONT)");
+ }
+ }
+
+ return EXIT_SUCCESS;
+}
+
+/* built-in 'help' handler */
+static int builtin_help(struct child_prog ATTRIBUTE_UNUSED *dummy)
+{
+ const struct built_in_command *x;
+
+ printf("\nBuilt-in commands:\n"
+ "-------------------\n");
+ for (x = bltins; x <= &VEC_LAST(bltins); x++) {
+ if (x->descr == NULL)
+ continue;
+ printf("%s\t%s\n", x->cmd, x->descr);
+ }
+ bb_putchar('\n');
+ return EXIT_SUCCESS;
+}
+
+/* built-in 'jobs' handler */
+static int builtin_jobs(struct child_prog *child)
+{
+ struct job *job;
+ const 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 ATTRIBUTE_UNUSED *dummy)
+{
+ update_cwd();
+ 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)
+ bb_perror_msg("export");
+#if ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ if (strncmp(v, "PS1=", 4) == 0)
+ PS1 = getenv("PS1");
+#endif
+
+#if ENABLE_LOCALE_SUPPORT
+ // TODO: why getenv? "" would be just as good...
+ 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;
+ char *s;
+ char string[MAX_READ];
+
+ if (child->argv[1]) {
+ /* argument (VAR) given: put "VAR=" into buffer */
+ safe_strncpy(string, child->argv[1], MAX_READ-1);
+ len = strlen(string);
+ string[len++] = '=';
+ string[len] = '\0';
+ fgets(&string[len], sizeof(string) - len, stdin); /* read string */
+ res = strlen(string);
+ if (res > len)
+ string[--res] = '\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;
+ s = strdup(string);
+ if (s)
+ res = putenv(s);
+ if (res)
+ bb_perror_msg("read");
+ } 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;
+
+ input = fopen_or_warn(child->argv[1], "r");
+ if (!input) {
+ return EXIT_FAILURE;
+ }
+
+ llist_add_to(&close_me_list, (void *)(long)fileno(input));
+ /* Now run the file */
+ status = busy_loop(input);
+ fclose(input);
+ llist_pop(&close_me_list);
+ return status;
+}
+
+/* built-in 'unset VAR' handler */
+static int builtin_unset(struct child_prog *child)
+{
+ if (child->argv[1] == NULL) {
+ printf(bb_msg_requires_arg, "unset");
+ return EXIT_FAILURE;
+ }
+ unsetenv(child->argv[1]);
+ return EXIT_SUCCESS;
+}
+
+#if ENABLE_LASH_JOB_CONTROL
+/* 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 ENABLE_LASH_PIPE_N_REDIRECTS
+ free(cmd->progs[i].redirects);
+#endif
+ }
+ free(cmd->progs);
+ free(cmd->text);
+ 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 (childpid == -1 && errno != ECHILD)
+ bb_perror_msg("waitpid");
+}
+#else
+static void checkjobs(struct jobset *j_list)
+{
+}
+static void free_job(struct job *cmd)
+{
+}
+static void remove_job(struct jobset *j_list, struct job *job)
+{
+}
+#endif
+
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+/* 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 = open3_or_warn(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!) */
+ return 1;
+ }
+
+ if (openfd != redir->fd) {
+ if (squirrel && redir->fd < 3) {
+ squirrel[redir->fd] = dup(redir->fd);
+ close_on_exec_on(squirrel[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);
+ }
+ }
+}
+#else
+static inline int setup_redirects(struct child_prog *prog, int squirrel[])
+{
+ return 0;
+}
+static inline void restore_redirects(int squirrel[])
+{
+}
+#endif
+
+static inline void cmdedit_set_initial_prompt(void)
+{
+#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ PS1 = NULL;
+#else
+ PS1 = getenv("PS1");
+ if (PS1 == 0)
+ PS1 = "\\w \\$ ";
+#endif
+}
+
+static inline const char* setup_prompt_string(void)
+{
+#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ /* Set up the prompt */
+ if (shell_context == 0) {
+ char *ns;
+ free((char*)PS1);
+ ns = xmalloc(strlen(cwd)+4);
+ sprintf(ns, "%s %c ", cwd, (geteuid() != 0) ? '$': '#');
+ PS1 = ns;
+ return ns;
+ } else {
+ return PS2;
+ }
+#else
+ return (shell_context == 0)? PS1 : PS2;
+#endif
+}
+
+#if ENABLE_FEATURE_EDITING
+static line_input_t *line_input_state;
+#endif
+
+static int get_command_bufsiz(FILE * source, char *command)
+{
+ const char *prompt_str;
+
+ if (source == NULL) {
+ if (local_pending_command) {
+ /* a command specified (-c option): return it & mark it done */
+ strncpy(command, local_pending_command, BUFSIZ);
+ local_pending_command = NULL;
+ return 0;
+ }
+ return 1;
+ }
+
+ if (source == stdin) {
+ prompt_str = setup_prompt_string();
+
+#if ENABLE_FEATURE_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)
+ */
+ read_line_input(prompt_str, command, BUFSIZ, line_input_state);
+ return 0;
+#else
+ fputs(prompt_str, stdout);
+#endif
+ }
+
+ if (!fgets(command, BUFSIZ - 2, source)) {
+ if (source == stdin)
+ bb_putchar('\n');
+ return 1;
+ }
+
+ return 0;
+}
+
+static char * strsep_space(char *string, int * ix)
+{
+ /* Short circuit the trivial case */
+ if (!string || ! string[*ix])
+ return NULL;
+
+ /* Find the end of the token. */
+ while (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[*ix] && (isspace)(string[*ix]) ) {
+ (*ix)++;
+ }
+
+ if (!*ix) {
+ /* Nothing useful was found */
+ return NULL;
+ }
+
+ return xstrndup(string, *ix);
+}
+
+static int expand_arguments(char *command)
+{
+ static const char out_of_space[] ALIGN1 = "out of space during expansion";
+
+ int total_length = 0, length, i, retval, ix = 0;
+ expand_t expand_result;
+ char *tmpcmd, *cmd, *cmd_copy;
+ char *src, *dst, *var;
+ 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] = bb_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 = xstrdup(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);
+ bb_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. */
+ bb_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) {
+ bb_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(global_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+1;
+ if (ixx >= global_argc) {
+ var = '\0';
+ } else {
+ var = global_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 = (char*)"";
+ }
+ {
+ int subst_len = strlen(var);
+ int trail_len = strlen(src);
+ if (dst+subst_len+trail_len >= command+BUFSIZ) {
+ bb_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;
+ int argc_l;
+ int flag;
+ int argv_alloced;
+ char quote = '\0';
+ struct child_prog *prog;
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+ int i;
+ char *chptr;
+#endif
+
+ /* skip leading white space */
+ *command_ptr = skip_whitespace(*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 = xzalloc(2*strlen(*command_ptr) + 1);
+ job->text = NULL;
+
+ prog = job->progs;
+ prog->num_redirects = 0;
+ prog->is_stopped = 0;
+ prog->family = job;
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+ prog->redirects = NULL;
+#endif
+
+ argv_alloced = 5;
+ prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
+ prog->argv[0] = job->cmdbuf;
+
+ flag = argc_l = 0;
+ buf = command;
+ src = *command_ptr;
+ while (*src && !(flag & LASH_OPT_DONE)) {
+ if (quote == *src) {
+ quote = '\0';
+ } else if (quote) {
+ if (*src == '\\') {
+ src++;
+ if (!*src) {
+ bb_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] || (flag & LASH_OPT_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;
+ flag ^= LASH_OPT_SAW_QUOTE;
+ }
+ } else
+ switch (*src) {
+ case '"':
+ case '\'':
+ quote = *src;
+ flag |= LASH_OPT_SAW_QUOTE;
+ break;
+
+ case '#': /* comment */
+ if (*(src-1)== '$')
+ *buf++ = *src;
+ else
+ flag |= LASH_OPT_DONE;
+ break;
+
+#if ENABLE_LASH_PIPE_N_REDIRECTS
+ 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;
+ chptr = skip_whitespace(chptr);
+
+ if (!*chptr) {
+ bb_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] || flag & LASH_OPT_SAW_QUOTE)
+ argc_l++;
+ if (!argc_l) {
+ goto empty_command_in_pipe;
+ }
+ 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++;
+ src = skip_whitespace(src);
+
+ if (!*src) {
+empty_command_in_pipe:
+ bb_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;
+#endif
+
+#if ENABLE_LASH_JOB_CONTROL
+ case '&': /* background */
+ *inbg = 1;
+ /* fallthrough */
+#endif
+ case ';': /* multiple commands */
+ flag |= LASH_OPT_DONE;
+ return_command = *command_ptr + (src - *command_ptr) + 1;
+ break;
+
+ case '\\':
+ src++;
+ if (!*src) {
+ bb_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] || flag & LASH_OPT_SAW_QUOTE) {
+ argc_l++;
+ }
+ if (!argc_l) {
+ free_job(job);
+ return 0;
+ }
+ prog->argv[argc_l] = NULL;
+
+ if (!return_command) {
+ job->text = xstrdup(*command_ptr);
+ } else {
+ /* This leaves any trailing spaces, which is a bit sloppy */
+ job->text = xstrndup(*command_ptr, return_command - *command_ptr);
+ }
+
+ *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)
+{
+ const struct built_in_command *x;
+
+ /* 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.
+ */
+ /* Check if the command matches any of the forking builtins. */
+ for (x = bltins; x <= &VEC_LAST(bltins); x++) {
+ if (strcmp(child->argv[0], x->cmd) == 0) {
+ _exit(x->function(child));
+ }
+ }
+
+ /* Check if the command matches any busybox internal
+ * commands ("applets") here. Following discussions from
+ * November 2000 on busybox@busybox.net, don't use
+ * bb_get_last_path_component_nostrip(). 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.
+ */
+ if (ENABLE_FEATURE_SH_STANDALONE) {
+ run_applet_and_exit(child->argv[0], child->argv);
+ }
+
+ execvp(child->argv[0], child->argv);
+
+ /* Do not use bb_perror_msg_and_die() here, since we must not
+ * call exit() but should call _exit() instead */
+ bb_simple_perror_msg(child->argv[0]);
+ _exit(EXIT_FAILURE);
+}
+
+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 ENABLE_LASH_JOB_CONTROL
+ 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 */
+ /* Ignore errors since child could have already exited */
+ tcsetpgrp(shell_terminal, newjob->pgrp);
+ }
+#endif
+}
+
+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 */
+ const struct built_in_command *x;
+ struct child_prog *child;
+
+ nextin = 0;
+ for (i = 0; i < newjob->num_progs; i++) {
+ child = &(newjob->progs[i]);
+
+ nextout = 1;
+ if ((i + 1) < newjob->num_progs) {
+ xpipe(pipefds);
+ nextout = pipefds[1];
+ } else if (outpipe[1] != -1) {
+ nextout = outpipe[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) {
+ int rcode;
+ int squirrel[] = {-1, -1, -1};
+
+ /* Check if the command sets an environment variable. */
+ if (strchr(child->argv[0], '=') != NULL) {
+ child->argv[1] = child->argv[0];
+ return builtin_export(child);
+ }
+
+ for (x = bltins; x <= &VEC_LAST(bltins); x++) {
+ if (strcmp(child->argv[0], x->cmd) == 0) {
+ setup_redirects(child, squirrel);
+ rcode = x->function(child);
+ restore_redirects(squirrel);
+ return rcode;
+ }
+ }
+#if ENABLE_FEATURE_SH_STANDALONE
+ {
+ const struct bb_applet *a = find_applet_by_name(child->argv[i]);
+ if (a && a->nofork) {
+ setup_redirects(child, squirrel);
+ rcode = run_nofork_applet(a, child->argv + i);
+ restore_redirects(squirrel);
+ return rcode;
+ }
+ }
+#endif
+ }
+
+#if BB_MMU
+ child->pid = fork();
+#else
+ child->pid = vfork();
+#endif
+ if (!child->pid) {
+ /* 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 open filehandles. */
+ while (close_me_list)
+ close((long)llist_pop(&close_me_list));
+
+ 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;
+ int i;
+ int inbg = 0;
+ int status;
+#if ENABLE_LASH_JOB_CONTROL
+ pid_t parent_pgrp;
+ /* save current owner of TTY so we can restore it on exit */
+ parent_pgrp = tcgetpgrp(shell_terminal);
+#endif
+ newjob.job_list = &job_list;
+ newjob.job_context = DEFAULT_CONTEXT;
+
+ command = xzalloc(BUFSIZ);
+
+ 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_bufsiz(input, command))
+ break;
+ next_command = command;
+ }
+
+ if (!expand_arguments(next_command)) {
+ free(command);
+ command = xzalloc(BUFSIZ);
+ 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 = xzalloc(BUFSIZ);
+ 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) {
+ if (errno != ECHILD) {
+ bb_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;
+ }
+ }
+#if ENABLE_LASH_JOB_CONTROL
+ 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)
+ bb_perror_msg("tcsetpgrp");
+ }
+#endif
+ }
+ }
+ free(command);
+
+#if ENABLE_LASH_JOB_CONTROL
+ /* return controlling TTY back to parent process group before exiting */
+ if (tcsetpgrp(shell_terminal, parent_pgrp) && errno != ENOTTY)
+ bb_perror_msg("tcsetpgrp");
+#endif
+
+ /* return exit status if called with "-c" */
+ if (input == NULL && WIFEXITED(status))
+ return WEXITSTATUS(status);
+
+ return 0;
+}
+
+#if ENABLE_FEATURE_CLEAN_UP
+static void free_memory(void)
+{
+ free(cwd);
+
+ if (job_list.fg && !job_list.fg->running_progs) {
+ remove_job(&job_list, job_list.fg);
+ }
+}
+#else
+void free_memory(void);
+#endif
+
+#if ENABLE_LASH_JOB_CONTROL
+/* 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(void)
+{
+ int status;
+ pid_t shell_pgrp;
+
+ /* Loop until we are in the foreground. */
+ while ((status = tcgetpgrp(shell_terminal)) >= 0) {
+ shell_pgrp = getpgrp();
+ if (status == shell_pgrp) {
+ 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);
+}
+#else
+static inline void setup_job_control(void)
+{
+}
+#endif
+
+int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int lash_main(int argc, char **argv)
+{
+ unsigned opt;
+ FILE *input = stdin;
+
+ global_argc = argc;
+ global_argv = argv;
+
+#if ENABLE_FEATURE_EDITING
+ line_input_state = new_line_input_t(FOR_SHELL);
+#endif
+
+ /* These variables need re-initializing when recursing */
+ last_jobid = 0;
+ close_me_list = NULL;
+ job_list.head = NULL;
+ job_list.fg = NULL;
+ last_return_code = 1;
+
+ if (global_argv[0] && global_argv[0][0] == '-') {
+ FILE *prof_input;
+ prof_input = fopen("/etc/profile", "r");
+ if (prof_input) {
+ llist_add_to(&close_me_list, (void *)(long)fileno(prof_input));
+ /* Now run the file */
+ busy_loop(prof_input);
+ fclose_if_not_stdin(prof_input);
+ llist_pop(&close_me_list);
+ }
+ }
+
+ opt = getopt32(argv, "+ic:", &local_pending_command);
+#define LASH_OPT_i (1<<0)
+#define LASH_OPT_c (1<<1)
+ if (opt & LASH_OPT_c) {
+ input = NULL;
+ optind++;
+ global_argv += optind;
+ }
+ /* 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 (global_argv[optind] == NULL && input == stdin
+ && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
+ ) {
+ opt |= LASH_OPT_i;
+ }
+ setup_job_control();
+ if (opt & LASH_OPT_i) {
+ /* Looks like they want an interactive shell */
+ if (!ENABLE_FEATURE_SH_EXTRA_QUIET) {
+ printf("\n\n%s built-in shell (lash)\n"
+ "Enter 'help' for a list of built-in commands.\n\n",
+ bb_banner);
+ }
+ } else if (!local_pending_command && global_argv[optind]) {
+ //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
+ input = xfopen(global_argv[optind], "r");
+ /* be lazy, never mark this closed */
+ llist_add_to(&close_me_list, (void *)(long)fileno(input));
+ }
+
+ /* initialize the cwd -- this is never freed...*/
+ update_cwd();
+
+ if (ENABLE_FEATURE_CLEAN_UP) atexit(free_memory);
+
+ if (ENABLE_FEATURE_EDITING) cmdedit_set_initial_prompt();
+ else PS1 = NULL;
+
+ return busy_loop(input);
+}