/* shell.c -- GNU's idea of the POSIX shell specification. */ /* Copyright (C) 1987-2009 Free Software Foundation, Inc. This file is part of GNU Bash, the Bourne Again SHell. Bash 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 3 of the License, or (at your option) any later version. Bash 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 Bash. If not, see . */ /* Birthdate: Sunday, January 10th, 1988. Initial author: Brian Fox */ #define INSTALL_DEBUG_MODE #include "config.h" #include "bashtypes.h" #if !defined (_MINIX) && defined (HAVE_SYS_FILE_H) # include #endif #include "posixstat.h" #include "posixtime.h" #include "bashansi.h" #include #include #include #include "filecntl.h" #include #if defined (HAVE_UNISTD_H) # include #endif #include "bashintl.h" #define NEED_SH_SETLINEBUF_DECL /* used in externs.h */ #include "shell.h" #include "flags.h" #include "trap.h" #include "mailcheck.h" #include "builtins.h" #include "builtins/common.h" #if defined (JOB_CONTROL) #include "jobs.h" #endif /* JOB_CONTROL */ #include "input.h" #include "execute_cmd.h" #include "findcmd.h" #if defined (USING_BASH_MALLOC) && defined (DEBUG) && !defined (DISABLE_MALLOC_WRAPPERS) # include #endif #if defined (HISTORY) # include "bashhist.h" # include #endif #if defined (READLINE) # include "bashline.h" #endif #include #include #if defined (__OPENNT) # include #endif #if !defined (HAVE_GETPW_DECLS) extern struct passwd *getpwuid (); #endif /* !HAVE_GETPW_DECLS */ #if !defined (errno) extern int errno; #endif #if defined (NO_MAIN_ENV_ARG) extern char **environ; /* used if no third argument to main() */ #endif extern char *dist_version, *release_status; extern int patch_level, build_version; extern int shell_level; extern int subshell_environment; extern int last_command_exit_value; extern int line_number; extern int expand_aliases; extern int array_needs_making; extern int gnu_error_format; extern char *primary_prompt, *secondary_prompt; extern char *this_command_name; /* Non-zero means that this shell has already been run; i.e. you should call shell_reinitialize () if you need to start afresh. */ int shell_initialized = 0; COMMAND *global_command = (COMMAND *)NULL; /* Information about the current user. */ struct user_info current_user = { (uid_t)-1, (uid_t)-1, (gid_t)-1, (gid_t)-1, (char *)NULL, (char *)NULL, (char *)NULL }; /* The current host's name. */ char *current_host_name = (char *)NULL; /* Non-zero means that this shell is a login shell. Specifically: 0 = not login shell. 1 = login shell from getty (or equivalent fake out) -1 = login shell from "--login" (or -l) flag. -2 = both from getty, and from flag. */ int login_shell = 0; /* Non-zero means that at this moment, the shell is interactive. In general, this means that the shell is at this moment reading input from the keyboard. */ int interactive = 0; /* Non-zero means that the shell was started as an interactive shell. */ int interactive_shell = 0; /* Non-zero means to send a SIGHUP to all jobs when an interactive login shell exits. */ int hup_on_exit = 0; /* Non-zero means to list status of running and stopped jobs at shell exit */ int check_jobs_at_exit = 0; /* Non-zero means to change to a directory name supplied as a command name */ int autocd = 0; /* Tells what state the shell was in when it started: 0 = non-interactive shell script 1 = interactive 2 = -c command 3 = wordexp evaluation This is a superset of the information provided by interactive_shell. */ int startup_state = 0; /* Special debugging helper. */ int debugging_login_shell = 0; /* The environment that the shell passes to other commands. */ char **shell_environment; /* Non-zero when we are executing a top-level command. */ int executing = 0; /* The number of commands executed so far. */ int current_command_number = 1; /* Non-zero is the recursion depth for commands. */ int indirection_level = 0; /* The name of this shell, as taken from argv[0]. */ char *shell_name = (char *)NULL; /* time in seconds when the shell was started */ time_t shell_start_time; /* Are we running in an emacs shell window? */ int running_under_emacs; /* Do we have /dev/fd? */ #ifdef HAVE_DEV_FD int have_devfd = HAVE_DEV_FD; #else int have_devfd = 0; #endif /* The name of the .(shell)rc file. */ static char *bashrc_file = "~/.bashrc"; /* Non-zero means to act more like the Bourne shell on startup. */ static int act_like_sh; /* Non-zero if this shell is being run by `su'. */ static int su_shell; /* Non-zero if we have already expanded and sourced $ENV. */ static int sourced_env; /* Is this shell running setuid? */ static int running_setuid; /* Values for the long-winded argument names. */ static int debugging; /* Do debugging things. */ static int no_rc; /* Don't execute ~/.bashrc */ static int no_profile; /* Don't execute .profile */ static int do_version; /* Display interesting version info. */ static int make_login_shell; /* Make this shell be a `-bash' shell. */ static int want_initial_help; /* --help option */ int debugging_mode = 0; /* In debugging mode with --debugger */ int no_line_editing = 0; /* Don't do fancy line editing. */ int dump_translatable_strings; /* Dump strings in $"...", don't execute. */ int dump_po_strings; /* Dump strings in $"..." in po format */ int wordexp_only = 0; /* Do word expansion only */ int protected_mode = 0; /* No command substitution with --wordexp */ #if defined (STRICT_POSIX) int posixly_correct = 1; /* Non-zero means posix.2 superset. */ #else int posixly_correct = 0; /* Non-zero means posix.2 superset. */ #endif /* Some long-winded argument names. These are obviously new. */ #define Int 1 #define Charp 2 static const struct { const char *name; int type; int *int_value; char **char_value; } long_args[] = { { "debug", Int, &debugging, (char **)0x0 }, #if defined (DEBUGGER) { "debugger", Int, &debugging_mode, (char **)0x0 }, #endif { "dump-po-strings", Int, &dump_po_strings, (char **)0x0 }, { "dump-strings", Int, &dump_translatable_strings, (char **)0x0 }, { "help", Int, &want_initial_help, (char **)0x0 }, { "init-file", Charp, (int *)0x0, &bashrc_file }, { "login", Int, &make_login_shell, (char **)0x0 }, { "noediting", Int, &no_line_editing, (char **)0x0 }, { "noprofile", Int, &no_profile, (char **)0x0 }, { "norc", Int, &no_rc, (char **)0x0 }, { "posix", Int, &posixly_correct, (char **)0x0 }, { "protected", Int, &protected_mode, (char **)0x0 }, { "rcfile", Charp, (int *)0x0, &bashrc_file }, #if defined (RESTRICTED_SHELL) { "restricted", Int, &restricted, (char **)0x0 }, #endif { "verbose", Int, &echo_input_at_read, (char **)0x0 }, { "version", Int, &do_version, (char **)0x0 }, #if defined (WORDEXP_OPTION) { "wordexp", Int, &wordexp_only, (char **)0x0 }, #endif { (char *)0x0, Int, (int *)0x0, (char **)0x0 } }; /* These are extern so execute_simple_command can set them, and then longjmp back to main to execute a shell script, instead of calling main () again and resulting in indefinite, possibly fatal, stack growth. */ procenv_t subshell_top_level; int subshell_argc; char **subshell_argv; char **subshell_envp; #if defined (BUFFERED_INPUT) /* The file descriptor from which the shell is reading input. */ int default_buffered_input = -1; #endif /* The following two variables are not static so they can show up in $-. */ int read_from_stdin; /* -s flag supplied */ int want_pending_command; /* -c flag supplied */ /* This variable is not static so it can be bound to $BASH_EXECUTION_STRING */ char *command_execution_string; /* argument to -c option */ int malloc_trace_at_exit = 0; static int shell_reinitialized = 0; static FILE *default_input; static STRING_INT_ALIST *shopt_alist; static int shopt_ind = 0, shopt_len = 0; static int parse_long_options __P((char **, int, int)); static int parse_shell_options __P((char **, int, int)); static int bind_args __P((char **, int, int, int)); static void start_debugger __P((void)); static void add_shopt_to_alist __P((char *, int)); static void run_shopt_alist __P((void)); static void execute_env_file __P((char *)); static void run_startup_files __P((void)); static int open_shell_script __P((char *)); static void set_bash_input __P((void)); static int run_one_command __P((char *)); #if defined (WORDEXP_OPTION) static int run_wordexp __P((char *)); #endif static int uidget __P((void)); static void init_interactive __P((void)); static void init_noninteractive __P((void)); static void init_interactive_script __P((void)); static void set_shell_name __P((char *)); static void shell_initialize __P((void)); static void shell_reinitialize __P((void)); static void show_shell_usage __P((FILE *, int)); #ifdef __CYGWIN__ static void _cygwin32_check_tmp () { struct stat sb; if (stat ("/tmp", &sb) < 0) internal_warning (_("could not find /tmp, please create!")); else { if (S_ISDIR (sb.st_mode) == 0) internal_warning (_("/tmp must be a valid directory name")); } } #endif /* __CYGWIN__ */ #if defined (NO_MAIN_ENV_ARG) /* systems without third argument to main() */ int main (argc, argv) int argc; char **argv; #else /* !NO_MAIN_ENV_ARG */ int main (argc, argv, env) int argc; char **argv, **env; #endif /* !NO_MAIN_ENV_ARG */ { register int i; int code, old_errexit_flag; #if defined (RESTRICTED_SHELL) int saverst; #endif volatile int locally_skip_execution; volatile int arg_index, top_level_arg_index; #ifdef __OPENNT char **env; env = environ; #endif /* __OPENNT */ USE_VAR(argc); USE_VAR(argv); USE_VAR(env); USE_VAR(code); USE_VAR(old_errexit_flag); #if defined (RESTRICTED_SHELL) USE_VAR(saverst); #endif /* Catch early SIGINTs. */ code = setjmp (top_level); if (code) exit (2); xtrace_init (); #if defined (USING_BASH_MALLOC) && defined (DEBUG) && !defined (DISABLE_MALLOC_WRAPPERS) # if 1 malloc_set_register (1); # endif #endif check_dev_tty (); #ifdef __CYGWIN__ _cygwin32_check_tmp (); #endif /* __CYGWIN__ */ /* Wait forever if we are debugging a login shell. */ while (debugging_login_shell) sleep (3); set_default_locale (); running_setuid = uidget (); if (getenv ("POSIXLY_CORRECT") || getenv ("POSIX_PEDANTIC")) posixly_correct = 1; #if defined (USE_GNU_MALLOC_LIBRARY) mcheck (programming_error, (void (*) ())0); #endif /* USE_GNU_MALLOC_LIBRARY */ if (setjmp (subshell_top_level)) { argc = subshell_argc; argv = subshell_argv; env = subshell_envp; sourced_env = 0; } shell_reinitialized = 0; /* Initialize `local' variables for all `invocations' of main (). */ arg_index = 1; if (arg_index > argc) arg_index = argc; command_execution_string = (char *)NULL; want_pending_command = locally_skip_execution = read_from_stdin = 0; default_input = stdin; #if defined (BUFFERED_INPUT) default_buffered_input = -1; #endif /* Fix for the `infinite process creation' bug when running shell scripts from startup files on System V. */ login_shell = make_login_shell = 0; /* If this shell has already been run, then reinitialize it to a vanilla state. */ if (shell_initialized || shell_name) { /* Make sure that we do not infinitely recurse as a login shell. */ if (*shell_name == '-') shell_name++; shell_reinitialize (); if (setjmp (top_level)) exit (2); } shell_environment = env; set_shell_name (argv[0]); shell_start_time = NOW; /* NOW now defined in general.h */ /* Parse argument flags from the input line. */ /* Find full word arguments first. */ arg_index = parse_long_options (argv, arg_index, argc); if (want_initial_help) { show_shell_usage (stdout, 1); exit (EXECUTION_SUCCESS); } if (do_version) { show_shell_version (1); exit (EXECUTION_SUCCESS); } /* All done with full word options; do standard shell option parsing.*/ this_command_name = shell_name; /* for error reporting */ arg_index = parse_shell_options (argv, arg_index, argc); /* If user supplied the "--login" (or -l) flag, then set and invert LOGIN_SHELL. */ if (make_login_shell) { login_shell++; login_shell = -login_shell; } set_login_shell ("login_shell", login_shell != 0); if (dump_po_strings) dump_translatable_strings = 1; if (dump_translatable_strings) read_but_dont_execute = 1; if (running_setuid && privileged_mode == 0 && act_like_sh == 0) disable_priv_mode (); /* Need to get the argument to a -c option processed in the above loop. The next arg is a command to execute, and the following args are $0...$n respectively. */ if (want_pending_command) { command_execution_string = argv[arg_index]; if (command_execution_string == 0) { report_error (_("%s: option requires an argument"), "-c"); exit (EX_BADUSAGE); } arg_index++; } this_command_name = (char *)NULL; cmd_init(); /* initialize the command object caches */ /* First, let the outside world know about our interactive status. 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 error is a terminal Refer to Posix.2, the description of the `sh' utility. */ if (forced_interactive || /* -i flag */ (!command_execution_string && /* No -c command and ... */ wordexp_only == 0 && /* No --wordexp and ... */ ((arg_index == argc) || /* no remaining args or... */ read_from_stdin) && /* -s flag with args, and */ isatty (fileno (stdin)) && /* Input is a terminal and */ isatty (fileno (stderr)))) /* error output is a terminal. */ init_interactive (); else init_noninteractive (); #define CLOSE_FDS_AT_LOGIN #if defined (CLOSE_FDS_AT_LOGIN) /* * Some systems have the bad habit of starting login shells with lots of open * file descriptors. For instance, most systems that have picked up the * pre-4.0 Sun YP code leave a file descriptor open each time you call one * of the getpw* functions, and it's set to be open across execs. That * means one for login, one for xterm, one for shelltool, etc. */ if (login_shell && interactive_shell) { for (i = 3; i < 20; i++) close (i); } #endif /* CLOSE_FDS_AT_LOGIN */ /* If we're in a strict Posix.2 mode, turn on interactive comments, alias expansion in non-interactive shells, and other Posix.2 things. */ if (posixly_correct) { bind_variable ("POSIXLY_CORRECT", "y", 0); sv_strict_posix ("POSIXLY_CORRECT"); } /* Now we run the shopt_alist and process the options. */ if (shopt_alist) run_shopt_alist (); /* From here on in, the shell must be a normal functioning shell. Variables from the environment are expected to be set, etc. */ shell_initialize (); set_default_lang (); set_default_locale_vars (); /* * M-x term -> TERM=eterm EMACS=22.1 (term:0.96) (eterm) * M-x shell -> TERM=dumb EMACS=t (no line editing) * M-x terminal -> TERM=emacs-em7955 EMACS= (line editing) */ if (interactive_shell) { char *term, *emacs; term = get_string_value ("TERM"); emacs = get_string_value ("EMACS"); /* Not sure any emacs terminal emulator sets TERM=emacs any more */ no_line_editing |= term && (STREQ (term, "emacs")); no_line_editing |= emacs && emacs[0] == 't' && emacs[1] == '\0' && STREQ (term, "dumb"); /* running_under_emacs == 2 for `eterm' */ running_under_emacs = (emacs != 0) || (term && STREQN (term, "emacs", 5)); running_under_emacs += term && STREQN (term, "eterm", 5) && emacs && strstr (emacs, "term"); if (running_under_emacs) gnu_error_format = 1; } top_level_arg_index = arg_index; old_errexit_flag = exit_immediately_on_error; /* Give this shell a place to longjmp to before executing the startup files. This allows users to press C-c to abort the lengthy startup. */ code = setjmp (top_level); if (code) { if (code == EXITPROG || code == ERREXIT) exit_shell (last_command_exit_value); else { #if defined (JOB_CONTROL) /* Reset job control, since run_startup_files turned it off. */ set_job_control (interactive_shell); #endif /* Reset value of `set -e', since it's turned off before running the startup files. */ exit_immediately_on_error += old_errexit_flag; locally_skip_execution++; } } arg_index = top_level_arg_index; /* Execute the start-up scripts. */ if (interactive_shell == 0) { unbind_variable ("PS1"); unbind_variable ("PS2"); interactive = 0; #if 0 /* This has already been done by init_noninteractive */ expand_aliases = posixly_correct; #endif } else { change_flag ('i', FLAG_ON); interactive = 1; } #if defined (RESTRICTED_SHELL) /* Set restricted_shell based on whether the basename of $0 indicates that the shell should be restricted or if the `-r' option was supplied at startup. */ restricted_shell = shell_is_restricted (shell_name); /* If the `-r' option is supplied at invocation, make sure that the shell is not in restricted mode when running the startup files. */ saverst = restricted; restricted = 0; #endif /* The startup files are run with `set -e' temporarily disabled. */ if (locally_skip_execution == 0 && running_setuid == 0) { old_errexit_flag = exit_immediately_on_error; exit_immediately_on_error = 0; run_startup_files (); exit_immediately_on_error += old_errexit_flag; } /* If we are invoked as `sh', turn on Posix mode. */ if (act_like_sh) { bind_variable ("POSIXLY_CORRECT", "y", 0); sv_strict_posix ("POSIXLY_CORRECT"); } #if defined (RESTRICTED_SHELL) /* Turn on the restrictions after executing the startup files. This means that `bash -r' or `set -r' invoked from a startup file will turn on the restrictions after the startup files are executed. */ restricted = saverst || restricted; if (shell_reinitialized == 0) maybe_make_restricted (shell_name); #endif /* RESTRICTED_SHELL */ #if defined (WORDEXP_OPTION) if (wordexp_only) { startup_state = 3; last_command_exit_value = run_wordexp (argv[arg_index]); exit_shell (last_command_exit_value); } #endif if (command_execution_string) { arg_index = bind_args (argv, arg_index, argc, 0); startup_state = 2; if (debugging_mode) start_debugger (); #if defined (ONESHOT) executing = 1; run_one_command (command_execution_string); exit_shell (last_command_exit_value); #else /* ONESHOT */ with_input_from_string (command_execution_string, "-c"); goto read_and_execute; #endif /* !ONESHOT */ } /* Get possible input filename and set up default_buffered_input or default_input as appropriate. */ if (arg_index != argc && read_from_stdin == 0) { open_shell_script (argv[arg_index]); arg_index++; } else if (interactive == 0) /* In this mode, bash is reading a script from stdin, which is a pipe or redirected file. */ #if defined (BUFFERED_INPUT) default_buffered_input = fileno (stdin); /* == 0 */ #else setbuf (default_input, (char *)NULL); #endif /* !BUFFERED_INPUT */ set_bash_input (); /* Bind remaining args to $1 ... $n */ arg_index = bind_args (argv, arg_index, argc, 1); if (debugging_mode && locally_skip_execution == 0 && running_setuid == 0) start_debugger (); /* Do the things that should be done only for interactive shells. */ if (interactive_shell) { /* Set up for checking for presence of mail. */ reset_mail_timer (); init_mail_dates (); #if defined (HISTORY) /* Initialize the interactive history stuff. */ bash_initialize_history (); /* Don't load the history from the history file if we've already saved some lines in this session (e.g., by putting `history -s xx' into one of the startup files). */ if (shell_initialized == 0 && history_lines_this_session == 0) load_history (); #endif /* HISTORY */ /* Initialize terminal state for interactive shells after the .bash_profile and .bashrc are interpreted. */ get_tty_state (); initialize_logging(); } #if !defined (ONESHOT) read_and_execute: #endif /* !ONESHOT */ shell_initialized = 1; /* Read commands until exit condition. */ reader_loop (); exit_shell (last_command_exit_value); } static int parse_long_options (argv, arg_start, arg_end) char **argv; int arg_start, arg_end; { int arg_index, longarg, i; char *arg_string; arg_index = arg_start; while ((arg_index != arg_end) && (arg_string = argv[arg_index]) && (*arg_string == '-')) { longarg = 0; /* Make --login equivalent to -login. */ if (arg_string[1] == '-' && arg_string[2]) { longarg = 1; arg_string++; } for (i = 0; long_args[i].name; i++) { if (STREQ (arg_string + 1, long_args[i].name)) { if (long_args[i].type == Int) *long_args[i].int_value = 1; else if (argv[++arg_index] == 0) { report_error (_("%s: option requires an argument"), long_args[i].name); exit (EX_BADUSAGE); } else *long_args[i].char_value = argv[arg_index]; break; } } if (long_args[i].name == 0) { if (longarg) { report_error (_("%s: invalid option"), argv[arg_index]); show_shell_usage (stderr, 0); exit (EX_BADUSAGE); } break; /* No such argument. Maybe flag arg. */ } arg_index++; } return (arg_index); } static int parse_shell_options (argv, arg_start, arg_end) char **argv; int arg_start, arg_end; { int arg_index; int arg_character, on_or_off, next_arg, i; char *o_option, *arg_string; arg_index = arg_start; while (arg_index != arg_end && (arg_string = argv[arg_index]) && (*arg_string == '-' || *arg_string == '+')) { /* There are flag arguments, so parse them. */ next_arg = arg_index + 1; /* A single `-' signals the end of options. From the 4.3 BSD sh. An option `--' means the same thing; this is the standard getopt(3) meaning. */ if (arg_string[0] == '-' && (arg_string[1] == '\0' || (arg_string[1] == '-' && arg_string[2] == '\0'))) return (next_arg); i = 1; on_or_off = arg_string[0]; while (arg_character = arg_string[i++]) { switch (arg_character) { case 'c': want_pending_command = 1; break; case 'l': make_login_shell = 1; break; case 's': read_from_stdin = 1; break; case 'o': o_option = argv[next_arg]; if (o_option == 0) { list_minus_o_opts (-1, (on_or_off == '-') ? 0 : 1); break; } if (set_minus_o_option (on_or_off, o_option) != EXECUTION_SUCCESS) exit (EX_BADUSAGE); next_arg++; break; case 'O': /* Since some of these can be overridden by the normal interactive/non-interactive shell initialization or initializing posix mode, we save the options and process them after initialization. */ o_option = argv[next_arg]; if (o_option == 0) { shopt_listopt (o_option, (on_or_off == '-') ? 0 : 1); break; } add_shopt_to_alist (o_option, on_or_off); next_arg++; break; case 'D': dump_translatable_strings = 1; break; default: if (change_flag (arg_character, on_or_off) == FLAG_ERROR) { report_error (_("%c%c: invalid option"), on_or_off, arg_character); show_shell_usage (stderr, 0); exit (EX_BADUSAGE); } } } /* Can't do just a simple increment anymore -- what about "bash -abouo emacs ignoreeof -hP"? */ arg_index = next_arg; } return (arg_index); } /* Exit the shell with status S. */ void exit_shell (s) int s; { fflush (stdout); /* XXX */ fflush (stderr); /* Do trap[0] if defined. Allow it to override the exit status passed to us. */ if (signal_is_trapped (0)) s = run_exit_trap (); #if defined (PROCESS_SUBSTITUTION) unlink_fifo_list (); #endif /* PROCESS_SUBSTITUTION */ #if defined (HISTORY) if (interactive_shell) maybe_save_shell_history (); #endif /* HISTORY */ #if defined (COPROCESS_SUPPORT) coproc_flush (); #endif #if defined (JOB_CONTROL) /* If the user has run `shopt -s huponexit', hangup all jobs when we exit an interactive login shell. ksh does this unconditionally. */ if (interactive_shell && login_shell && hup_on_exit) hangup_all_jobs (); /* If this shell is interactive, terminate all stopped jobs and restore the original terminal process group. Don't do this if we're in a subshell and calling exit_shell after, for example, a failed word expansion. */ if (subshell_environment == 0) end_job_control (); #endif /* JOB_CONTROL */ /* Always return the exit status of the last command to our parent. */ sh_exit (s); } /* A wrapper for exit that (optionally) can do other things, like malloc statistics tracing. */ void sh_exit (s) int s; { #if defined (MALLOC_DEBUG) && defined (USING_BASH_MALLOC) if (malloc_trace_at_exit) trace_malloc_stats (get_name_for_error (), (char *)NULL); #endif exit (s); } /* Source the bash startup files. If POSIXLY_CORRECT is non-zero, we obey the Posix.2 startup file rules: $ENV is expanded, and if the file it names exists, that file is sourced. The Posix.2 rules are in effect for interactive shells only. (section 4.56.5.3) */ /* Execute ~/.bashrc for most shells. Never execute it if ACT_LIKE_SH is set, or if NO_RC is set. If the executable file "/usr/gnu/src/bash/foo" contains: #!/usr/gnu/bin/bash echo hello then: COMMAND EXECUTE BASHRC -------------------------------- bash -c foo NO bash foo NO foo NO rsh machine ls YES (for rsh, which calls `bash -c') rsh machine foo YES (for shell started by rsh) NO (for foo!) echo ls | bash NO login NO bash YES */ static void execute_env_file (env_file) char *env_file; { char *fn; if (env_file && *env_file) { fn = expand_string_unsplit_to_string (env_file, Q_DOUBLE_QUOTES); if (fn && *fn) maybe_execute_file (fn, 1); FREE (fn); } } static void run_startup_files () { #if defined (JOB_CONTROL) int old_job_control; #endif int sourced_login, run_by_ssh; /* get the rshd/sshd case out of the way first. */ if (interactive_shell == 0 && no_rc == 0 && login_shell == 0 && act_like_sh == 0 && command_execution_string) { #ifdef SSH_SOURCE_BASHRC run_by_ssh = (find_variable ("SSH_CLIENT") != (SHELL_VAR *)0) || (find_variable ("SSH2_CLIENT") != (SHELL_VAR *)0); #else run_by_ssh = 0; #endif /* If we were run by sshd or we think we were run by rshd, execute ~/.bashrc if we are a top-level shell. */ if ((run_by_ssh || isnetconn (fileno (stdin))) && shell_level < 2) { #ifdef SYS_BASHRC # if defined (__OPENNT) maybe_execute_file (_prefixInstallPath(SYS_BASHRC, NULL, 0), 1); # else maybe_execute_file (SYS_BASHRC, 1); # endif #endif maybe_execute_file (bashrc_file, 1); return; } } #if defined (JOB_CONTROL) /* Startup files should be run without job control enabled. */ old_job_control = interactive_shell ? set_job_control (0) : 0; #endif sourced_login = 0; /* A shell begun with the --login (or -l) flag that is not in posix mode runs the login shell startup files, no matter whether or not it is interactive. If NON_INTERACTIVE_LOGIN_SHELLS is defined, run the startup files if argv[0][0] == '-' as well. */ #if defined (NON_INTERACTIVE_LOGIN_SHELLS) if (login_shell && posixly_correct == 0) #else if (login_shell < 0 && posixly_correct == 0) #endif { /* We don't execute .bashrc for login shells. */ no_rc++; /* Execute /etc/profile and one of the personal login shell initialization files. */ if (no_profile == 0) { maybe_execute_file (SYS_PROFILE, 1); if (act_like_sh) /* sh */ maybe_execute_file ("~/.profile", 1); else if ((maybe_execute_file ("~/.bash_profile", 1) == 0) && (maybe_execute_file ("~/.bash_login", 1) == 0)) /* bash */ maybe_execute_file ("~/.profile", 1); } sourced_login = 1; } /* A non-interactive shell not named `sh' and not in posix mode reads and executes commands from $BASH_ENV. If `su' starts a shell with `-c cmd' and `-su' as the name of the shell, we want to read the startup files. No other non-interactive shells read any startup files. */ if (interactive_shell == 0 && !(su_shell && login_shell)) { if (posixly_correct == 0 && act_like_sh == 0 && privileged_mode == 0 && sourced_env++ == 0) execute_env_file (get_string_value ("BASH_ENV")); return; } /* Interactive shell or `-su' shell. */ if (posixly_correct == 0) /* bash, sh */ { if (login_shell && sourced_login++ == 0) { /* We don't execute .bashrc for login shells. */ no_rc++; /* Execute /etc/profile and one of the personal login shell initialization files. */ if (no_profile == 0) { maybe_execute_file (SYS_PROFILE, 1); if (act_like_sh) /* sh */ maybe_execute_file ("~/.profile", 1); else if ((maybe_execute_file ("~/.bash_profile", 1) == 0) && (maybe_execute_file ("~/.bash_login", 1) == 0)) /* bash */ maybe_execute_file ("~/.profile", 1); } } /* bash */ if (act_like_sh == 0 && no_rc == 0) { #ifdef SYS_BASHRC # if defined (__OPENNT) maybe_execute_file (_prefixInstallPath(SYS_BASHRC, NULL, 0), 1); # else maybe_execute_file (SYS_BASHRC, 1); # endif #endif maybe_execute_file (bashrc_file, 1); } /* sh */ else if (act_like_sh && privileged_mode == 0 && sourced_env++ == 0) execute_env_file (get_string_value ("ENV")); } else /* bash --posix, sh --posix */ { /* bash and sh */ if (interactive_shell && privileged_mode == 0 && sourced_env++ == 0) execute_env_file (get_string_value ("ENV")); } #if defined (JOB_CONTROL) set_job_control (old_job_control); #endif } #if defined (RESTRICTED_SHELL) /* Return 1 if the shell should be a restricted one based on NAME or the value of `restricted'. Don't actually do anything, just return a boolean value. */ int shell_is_restricted (name) char *name; { char *temp; if (restricted) return 1; temp = base_pathname (name); if (*temp == '-') temp++; return (STREQ (temp, RESTRICTED_SHELL_NAME)); } /* Perhaps make this shell a `restricted' one, based on NAME. If the basename of NAME is "rbash", then this shell is restricted. The name of the restricted shell is a configurable option, see config.h. In a restricted shell, PATH, SHELL, ENV, and BASH_ENV are read-only and non-unsettable. Do this also if `restricted' is already set to 1; maybe the shell was started with -r. */ int maybe_make_restricted (name) char *name; { char *temp; temp = base_pathname (name); if (*temp == '-') temp++; if (restricted || (STREQ (temp, RESTRICTED_SHELL_NAME))) { set_var_read_only ("PATH"); set_var_read_only ("SHELL"); set_var_read_only ("ENV"); set_var_read_only ("BASH_ENV"); restricted = 1; } return (restricted); } #endif /* RESTRICTED_SHELL */ /* Fetch the current set of uids and gids and return 1 if we're running setuid or setgid. */ static int uidget () { uid_t u; u = getuid (); if (current_user.uid != u) { FREE (current_user.user_name); FREE (current_user.shell); FREE (current_user.home_dir); current_user.user_name = current_user.shell = current_user.home_dir = (char *)NULL; } current_user.uid = u; current_user.gid = getgid (); current_user.euid = geteuid (); current_user.egid = getegid (); /* See whether or not we are running setuid or setgid. */ return (current_user.uid != current_user.euid) || (current_user.gid != current_user.egid); } void disable_priv_mode () { setuid (current_user.uid); setgid (current_user.gid); current_user.euid = current_user.uid; current_user.egid = current_user.gid; } #if defined (WORDEXP_OPTION) static int run_wordexp (words) char *words; { int code, nw, nb; WORD_LIST *wl, *tl, *result; code = setjmp (top_level); if (code != NOT_JUMPED) { switch (code) { /* Some kind of throw to top_level has occured. */ case FORCE_EOF: return last_command_exit_value = 127; case ERREXIT: case EXITPROG: return last_command_exit_value; case DISCARD: return last_command_exit_value = 1; default: command_error ("run_wordexp", CMDERR_BADJUMP, code, 0); } } /* Run it through the parser to get a list of words and expand them */ if (words && *words) { with_input_from_string (words, "--wordexp"); if (parse_command () != 0) return (126); if (global_command == 0) { printf ("0\n0\n"); return (0); } if (global_command->type != cm_simple) return (126); wl = global_command->value.Simple->words; if (protected_mode) for (tl = wl; tl; tl = tl->next) tl->word->flags |= W_NOCOMSUB|W_NOPROCSUB; result = wl ? expand_words_no_vars (wl) : (WORD_LIST *)0; } else result = (WORD_LIST *)0; last_command_exit_value = 0; if (result == 0) { printf ("0\n0\n"); return (0); } /* Count up the number of words and bytes, and print them. Don't count the trailing NUL byte. */ for (nw = nb = 0, wl = result; wl; wl = wl->next) { nw++; nb += strlen (wl->word->word); } printf ("%u\n%u\n", nw, nb); /* Print each word on a separate line. This will have to be changed when the interface to glibc is completed. */ for (wl = result; wl; wl = wl->next) printf ("%s\n", wl->word->word); return (0); } #endif #if defined (ONESHOT) /* Run one command, given as the argument to the -c option. Tell parse_and_execute not to fork for a simple command. */ static int run_one_command (command) char *command; { int code; code = setjmp (top_level); if (code != NOT_JUMPED) { #if defined (PROCESS_SUBSTITUTION) unlink_fifo_list (); #endif /* PROCESS_SUBSTITUTION */ switch (code) { /* Some kind of throw to top_level has occured. */ case FORCE_EOF: return last_command_exit_value = 127; case ERREXIT: case EXITPROG: return last_command_exit_value; case DISCARD: return last_command_exit_value = 1; default: command_error ("run_one_command", CMDERR_BADJUMP, code, 0); } } return (parse_and_execute (savestring (command), "-c", SEVAL_NOHIST)); } #endif /* ONESHOT */ static int bind_args (argv, arg_start, arg_end, start_index) char **argv; int arg_start, arg_end, start_index; { register int i; WORD_LIST *args; for (i = arg_start, args = (WORD_LIST *)NULL; i < arg_end; i++) args = make_word_list (make_word (argv[i]), args); if (args) { args = REVERSE_LIST (args, WORD_LIST *); if (start_index == 0) /* bind to $0...$n for sh -c command */ { /* Posix.2 4.56.3 says that the first argument after sh -c command becomes $0, and the rest of the arguments become $1...$n */ shell_name = savestring (args->word->word); FREE (dollar_vars[0]); dollar_vars[0] = savestring (args->word->word); remember_args (args->next, 1); push_args (args->next); /* BASH_ARGV and BASH_ARGC */ } else /* bind to $1...$n for shell script */ { remember_args (args, 1); push_args (args); /* BASH_ARGV and BASH_ARGC */ } dispose_words (args); } return (i); } void unbind_args () { remember_args ((WORD_LIST *)NULL, 1); pop_args (); /* Reset BASH_ARGV and BASH_ARGC */ } static void start_debugger () { #if defined (DEBUGGER) && defined (DEBUGGER_START_FILE) int old_errexit; old_errexit = exit_immediately_on_error; exit_immediately_on_error = 0; maybe_execute_file (DEBUGGER_START_FILE, 1); function_trace_mode = 1; exit_immediately_on_error += old_errexit; #endif } static int open_shell_script (script_name) char *script_name; { int fd, e, fd_is_tty; char *filename, *path_filename, *t; char sample[80]; int sample_len; struct stat sb; #if defined (ARRAY_VARS) SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v; ARRAY *funcname_a, *bash_source_a, *bash_lineno_a; #endif filename = savestring (script_name); fd = open (filename, O_RDONLY); if ((fd < 0) && (errno == ENOENT) && (absolute_program (filename) == 0)) { e = errno; /* If it's not in the current directory, try looking through PATH for it. */ path_filename = find_path_file (script_name); if (path_filename) { free (filename); filename = path_filename; fd = open (filename, O_RDONLY); } else errno = e; } if (fd < 0) { e = errno; file_error (filename); exit ((e == ENOENT) ? EX_NOTFOUND : EX_NOINPUT); } free (dollar_vars[0]); dollar_vars[0] = savestring (script_name); #if defined (ARRAY_VARS) GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a); GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a); GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a); array_push (bash_source_a, filename); if (bash_lineno_a) { t = itos (executing_line_number ()); array_push (bash_lineno_a, t); free (t); } array_push (funcname_a, "main"); #endif #ifdef HAVE_DEV_FD fd_is_tty = isatty (fd); #else fd_is_tty = 0; #endif /* Only do this with non-tty file descriptors we can seek on. */ if (fd_is_tty == 0 && (lseek (fd, 0L, 1) != -1)) { /* Check to see if the `file' in `bash file' is a binary file according to the same tests done by execute_simple_command (), and report an error and exit if it is. */ sample_len = read (fd, sample, sizeof (sample)); if (sample_len < 0) { e = errno; if ((fstat (fd, &sb) == 0) && S_ISDIR (sb.st_mode)) internal_error (_("%s: is a directory"), filename); else { errno = e; file_error (filename); } exit (EX_NOEXEC); } else if (sample_len > 0 && (check_binary_file (sample, sample_len))) { internal_error (_("%s: cannot execute binary file"), filename); exit (EX_BINARY_FILE); } /* Now rewind the file back to the beginning. */ lseek (fd, 0L, 0); } /* Open the script. But try to move the file descriptor to a randomly large one, in the hopes that any descriptors used by the script will not match with ours. */ fd = move_to_high_fd (fd, 1, -1); #if defined (__CYGWIN__) && defined (O_TEXT) setmode (fd, O_TEXT); #endif #if defined (BUFFERED_INPUT) default_buffered_input = fd; SET_CLOSE_ON_EXEC (default_buffered_input); #else /* !BUFFERED_INPUT */ default_input = fdopen (fd, "r"); if (default_input == 0) { file_error (filename); exit (EX_NOTFOUND); } SET_CLOSE_ON_EXEC (fd); if (fileno (default_input) != fd) SET_CLOSE_ON_EXEC (fileno (default_input)); #endif /* !BUFFERED_INPUT */ /* Just about the only way for this code to be executed is if something like `bash -i /dev/stdin' is executed. */ if (interactive_shell && fd_is_tty) { dup2 (fd, 0); close (fd); fd = 0; #if defined (BUFFERED_INPUT) default_buffered_input = 0; #else fclose (default_input); default_input = stdin; #endif } else if (forced_interactive && fd_is_tty == 0) /* But if a script is called with something like `bash -i scriptname', we need to do a non-interactive setup here, since we didn't do it before. */ init_interactive_script (); free (filename); return (fd); } /* Initialize the input routines for the parser. */ static void set_bash_input () { /* Make sure the fd from which we are reading input is not in no-delay mode. */ #if defined (BUFFERED_INPUT) if (interactive == 0) sh_unset_nodelay_mode (default_buffered_input); else #endif /* !BUFFERED_INPUT */ sh_unset_nodelay_mode (fileno (stdin)); /* with_input_from_stdin really means `with_input_from_readline' */ if (interactive && no_line_editing == 0) with_input_from_stdin (); #if defined (BUFFERED_INPUT) else if (interactive == 0) with_input_from_buffered_stream (default_buffered_input, dollar_vars[0]); #endif /* BUFFERED_INPUT */ else with_input_from_stream (default_input, dollar_vars[0]); } /* Close the current shell script input source and forget about it. This is extern so execute_cmd.c:initialize_subshell() can call it. If CHECK_ZERO is non-zero, we close default_buffered_input even if it's the standard input (fd 0). */ void unset_bash_input (check_zero) int check_zero; { #if defined (BUFFERED_INPUT) if ((check_zero && default_buffered_input >= 0) || (check_zero == 0 && default_buffered_input > 0)) { close_buffered_fd (default_buffered_input); default_buffered_input = bash_input.location.buffered_fd = -1; bash_input.type = st_none; /* XXX */ } #else /* !BUFFERED_INPUT */ if (default_input) { fclose (default_input); default_input = (FILE *)NULL; } #endif /* !BUFFERED_INPUT */ } #if !defined (PROGRAM) # define PROGRAM "bash" #endif static void set_shell_name (argv0) char *argv0; { /* Here's a hack. If the name of this shell is "sh", then don't do any startup files; just try to be more like /bin/sh. */ shell_name = argv0 ? base_pathname (argv0) : PROGRAM; if (argv0 && *argv0 == '-') { if (*shell_name == '-') shell_name++; login_shell++; } if (shell_name[0] == 's' && shell_name[1] == 'h' && shell_name[2] == '\0') act_like_sh++; if (shell_name[0] == 's' && shell_name[1] == 'u' && shell_name[2] == '\0') su_shell++; shell_name = argv0 ? argv0 : PROGRAM; FREE (dollar_vars[0]); dollar_vars[0] = savestring (shell_name); /* A program may start an interactive shell with "execl ("/bin/bash", "-", NULL)". If so, default the name of this shell to our name. */ if (!shell_name || !*shell_name || (shell_name[0] == '-' && !shell_name[1])) shell_name = PROGRAM; } static void init_interactive () { expand_aliases = interactive_shell = startup_state = 1; interactive = 1; } static void init_noninteractive () { #if defined (HISTORY) bash_history_reinit (0); #endif /* HISTORY */ interactive_shell = startup_state = interactive = 0; expand_aliases = posixly_correct; /* XXX - was 0 not posixly_correct */ no_line_editing = 1; #if defined (JOB_CONTROL) set_job_control (0); #endif /* JOB_CONTROL */ } static void init_interactive_script () { init_noninteractive (); expand_aliases = interactive_shell = startup_state = 1; } void get_current_user_info () { struct passwd *entry; /* Don't fetch this more than once. */ if (current_user.user_name == 0) { entry = getpwuid (current_user.uid); if (entry) { current_user.user_name = savestring (entry->pw_name); current_user.shell = (entry->pw_shell && entry->pw_shell[0]) ? savestring (entry->pw_shell) : savestring ("/bin/sh"); current_user.home_dir = savestring (entry->pw_dir); } else { current_user.user_name = _("I have no name!"); current_user.user_name = savestring (current_user.user_name); current_user.shell = savestring ("/bin/sh"); current_user.home_dir = savestring ("/"); } endpwent (); } } /* Do whatever is necessary to initialize the shell. Put new initializations in here. */ static void shell_initialize () { char hostname[256]; /* Line buffer output for stderr and stdout. */ if (shell_initialized == 0) { sh_setlinebuf (stderr); sh_setlinebuf (stdout); } /* Sort the array of shell builtins so that the binary search in find_shell_builtin () works correctly. */ initialize_shell_builtins (); /* Initialize the trap signal handlers before installing our own signal handlers. traps.c:restore_original_signals () is responsible for restoring the original default signal handlers. That function is called when we make a new child. */ initialize_traps (); initialize_signals (0); /* It's highly unlikely that this will change. */ if (current_host_name == 0) { /* Initialize current_host_name. */ if (gethostname (hostname, 255) < 0) current_host_name = "??host??"; else current_host_name = savestring (hostname); } /* Initialize the stuff in current_user that comes from the password file. We don't need to do this right away if the shell is not interactive. */ if (interactive_shell) get_current_user_info (); /* Initialize our interface to the tilde expander. */ tilde_initialize (); /* Initialize internal and environment variables. Don't import shell functions from the environment if we are running in privileged or restricted mode or if the shell is running setuid. */ #if defined (RESTRICTED_SHELL) initialize_shell_variables (shell_environment, privileged_mode||restricted||running_setuid); #else initialize_shell_variables (shell_environment, privileged_mode||running_setuid); #endif /* Initialize the data structures for storing and running jobs. */ initialize_job_control (0); /* Initialize input streams to null. */ initialize_bash_input (); initialize_flags (); /* Initialize the shell options. Don't import the shell options from the environment variable $SHELLOPTS if we are running in privileged or restricted mode or if the shell is running setuid. */ #if defined (RESTRICTED_SHELL) initialize_shell_options (privileged_mode||restricted||running_setuid); initialize_bashopts (privileged_mode||restricted||running_setuid); #else initialize_shell_options (privileged_mode||running_setuid); initialize_bashopts (privileged_mode||running_setuid); #endif } /* Function called by main () when it appears that the shell has already had some initialization performed. This is supposed to reset the world back to a pristine state, as if we had been exec'ed. */ static void shell_reinitialize () { /* The default shell prompts. */ primary_prompt = PPROMPT; secondary_prompt = SPROMPT; /* Things that get 1. */ current_command_number = 1; /* We have decided that the ~/.bashrc file should not be executed for the invocation of each shell script. If the variable $ENV (or $BASH_ENV) is set, its value is used as the name of a file to source. */ no_rc = no_profile = 1; /* Things that get 0. */ login_shell = make_login_shell = interactive = executing = 0; debugging = do_version = line_number = last_command_exit_value = 0; forced_interactive = interactive_shell = subshell_environment = 0; expand_aliases = 0; #if defined (HISTORY) bash_history_reinit (0); #endif /* HISTORY */ #if defined (RESTRICTED_SHELL) restricted = 0; #endif /* RESTRICTED_SHELL */ /* Ensure that the default startup file is used. (Except that we don't execute this file for reinitialized shells). */ bashrc_file = "~/.bashrc"; /* Delete all variables and functions. They will be reinitialized when the environment is parsed. */ delete_all_contexts (shell_variables); delete_all_variables (shell_functions); reinit_special_variables (); #if defined (READLINE) bashline_reinitialize (); #endif shell_reinitialized = 1; } static void show_shell_usage (fp, extra) FILE *fp; int extra; { int i; char *set_opts, *s, *t; if (extra) fprintf (fp, _("GNU bash, version %s-(%s)\n"), shell_version_string (), MACHTYPE); fprintf (fp, _("Usage:\t%s [GNU long option] [option] ...\n\t%s [GNU long option] [option] script-file ...\n"), shell_name, shell_name); fputs (_("GNU long options:\n"), fp); for (i = 0; long_args[i].name; i++) fprintf (fp, "\t--%s\n", long_args[i].name); fputs (_("Shell options:\n"), fp); fputs (_("\t-irsD or -c command or -O shopt_option\t\t(invocation only)\n"), fp); for (i = 0, set_opts = 0; shell_builtins[i].name; i++) if (STREQ (shell_builtins[i].name, "set")) set_opts = savestring (shell_builtins[i].short_doc); if (set_opts) { s = strchr (set_opts, '['); if (s == 0) s = set_opts; while (*++s == '-') ; t = strchr (s, ']'); if (t) *t = '\0'; fprintf (fp, _("\t-%s or -o option\n"), s); free (set_opts); } if (extra) { fprintf (fp, _("Type `%s -c \"help set\"' for more information about shell options.\n"), shell_name); fprintf (fp, _("Type `%s -c help' for more information about shell builtin commands.\n"), shell_name); fprintf (fp, _("Use the `bashbug' command to report bugs.\n")); } } static void add_shopt_to_alist (opt, on_or_off) char *opt; int on_or_off; { if (shopt_ind >= shopt_len) { shopt_len += 8; shopt_alist = (STRING_INT_ALIST *)xrealloc (shopt_alist, shopt_len * sizeof (shopt_alist[0])); } shopt_alist[shopt_ind].word = opt; shopt_alist[shopt_ind].token = on_or_off; shopt_ind++; } static void run_shopt_alist () { register int i; for (i = 0; i < shopt_ind; i++) if (shopt_setopt (shopt_alist[i].word, (shopt_alist[i].token == '-')) != EXECUTION_SUCCESS) exit (EX_BADUSAGE); free (shopt_alist); shopt_alist = 0; shopt_ind = shopt_len = 0; }