/* execute_cmd.c -- Execute a COMMAND structure. */ /* Copyright (C) 1987-2022 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 . */ #include "config.h" #if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX) #pragma alloca #endif /* _AIX && RISC6000 && !__GNUC__ */ #include #include "chartypes.h" #include "bashtypes.h" #if !defined (_MINIX) && defined (HAVE_SYS_FILE_H) # include #endif #include "filecntl.h" #include "posixstat.h" #include #if defined (HAVE_SYS_PARAM_H) # include #endif #if defined (HAVE_UNISTD_H) # include #endif #include "posixtime.h" #if defined (HAVE_SYS_RESOURCE_H) && !defined (RLIMTYPE) # include #endif #if defined (HAVE_SYS_TIMES_H) && defined (HAVE_TIMES) # include #endif #include #if !defined (errno) extern int errno; #endif #define NEED_FPURGE_DECL #define NEED_SH_SETLINEBUF_DECL #include "bashansi.h" #include "bashintl.h" #include "memalloc.h" #include "shell.h" #include /* use <...> so we pick it up from the build directory */ #include "parser.h" #include "flags.h" #include "builtins.h" #include "hashlib.h" #include "jobs.h" #include "execute_cmd.h" #include "findcmd.h" #include "redir.h" #include "trap.h" #include "pathexp.h" #include "hashcmd.h" #if defined (COND_COMMAND) # include "test.h" #endif #include "builtins/common.h" #include "builtins/builtext.h" /* list of builtins */ #include "builtins/getopt.h" #include #include #if defined (BUFFERED_INPUT) # include "input.h" #endif #if defined (ALIAS) # include "alias.h" #endif #if defined (HISTORY) # include "bashhist.h" #endif #if defined (HAVE_MBSTR_H) && defined (HAVE_MBSCHR) # include /* mbschr */ #endif extern int command_string_index; extern char *the_printed_command; extern time_t shell_start_time; #if defined (HAVE_GETTIMEOFDAY) extern struct timeval shellstart; #endif #if 0 extern char *glob_argv_flags; #endif extern int close PARAMS((int)); /* Static functions defined and used in this file. */ static void close_pipes PARAMS((int, int)); static void do_piping PARAMS((int, int)); static void bind_lastarg PARAMS((char *)); static int shell_control_structure PARAMS((enum command_type)); static void cleanup_redirects PARAMS((REDIRECT *)); #if defined (JOB_CONTROL) static int restore_signal_mask PARAMS((sigset_t *)); #endif static int builtin_status PARAMS((int)); static int execute_for_command PARAMS((FOR_COM *)); #if defined (SELECT_COMMAND) static int displen PARAMS((const char *)); static int print_index_and_element PARAMS((int, int, WORD_LIST *)); static void indent PARAMS((int, int)); static void print_select_list PARAMS((WORD_LIST *, int, int, int)); static char *select_query PARAMS((WORD_LIST *, int, char *, int)); static int execute_select_command PARAMS((SELECT_COM *)); #endif #if defined (DPAREN_ARITHMETIC) static int execute_arith_command PARAMS((ARITH_COM *)); #endif #if defined (COND_COMMAND) static int execute_cond_node PARAMS((COND_COM *)); static int execute_cond_command PARAMS((COND_COM *)); #endif #if defined (COMMAND_TIMING) static int mkfmt PARAMS((char *, int, int, time_t, int)); static void print_formatted_time PARAMS((FILE *, char *, time_t, int, time_t, int, time_t, int, int)); static int time_command PARAMS((COMMAND *, int, int, int, struct fd_bitmap *)); #endif #if defined (ARITH_FOR_COMMAND) static intmax_t eval_arith_for_expr PARAMS((WORD_LIST *, int *)); static int execute_arith_for_command PARAMS((ARITH_FOR_COM *)); #endif static int execute_case_command PARAMS((CASE_COM *)); static int execute_while_command PARAMS((WHILE_COM *)); static int execute_until_command PARAMS((WHILE_COM *)); static int execute_while_or_until PARAMS((WHILE_COM *, int)); static int execute_if_command PARAMS((IF_COM *)); static int execute_null_command PARAMS((REDIRECT *, int, int, int)); static void fix_assignment_words PARAMS((WORD_LIST *)); static void fix_arrayref_words PARAMS((WORD_LIST *)); static int execute_simple_command PARAMS((SIMPLE_COM *, int, int, int, struct fd_bitmap *)); static int execute_builtin PARAMS((sh_builtin_func_t *, WORD_LIST *, int, int)); static int execute_function PARAMS((SHELL_VAR *, WORD_LIST *, int, struct fd_bitmap *, int, int)); static int execute_builtin_or_function PARAMS((WORD_LIST *, sh_builtin_func_t *, SHELL_VAR *, REDIRECT *, struct fd_bitmap *, int)); static void execute_subshell_builtin_or_function PARAMS((WORD_LIST *, REDIRECT *, sh_builtin_func_t *, SHELL_VAR *, int, int, int, struct fd_bitmap *, int)); static int execute_disk_command PARAMS((WORD_LIST *, REDIRECT *, char *, int, int, int, struct fd_bitmap *, int)); static char *getinterp PARAMS((char *, int, int *)); static void initialize_subshell PARAMS((void)); static int execute_in_subshell PARAMS((COMMAND *, int, int, int, struct fd_bitmap *)); #if defined (COPROCESS_SUPPORT) static void coproc_setstatus PARAMS((struct coproc *, int)); static int execute_coproc PARAMS((COMMAND *, int, int, struct fd_bitmap *)); #endif static int execute_pipeline PARAMS((COMMAND *, int, int, int, struct fd_bitmap *)); static int execute_connection PARAMS((COMMAND *, int, int, int, struct fd_bitmap *)); static int execute_intern_function PARAMS((WORD_DESC *, FUNCTION_DEF *)); /* Set to 1 if fd 0 was the subject of redirection to a subshell. Global so that reader_loop can set it to zero before executing a command. */ int stdin_redir; /* The name of the command that is currently being executed. `test' needs this, for example. */ char *this_command_name; /* The printed representation of the currently-executing command (same as the_printed_command), except when a trap is being executed. Useful for a debugger to know where exactly the program is currently executing. */ char *the_printed_command_except_trap; /* For catching RETURN in a function. */ int return_catch_flag; int return_catch_value; procenv_t return_catch; /* The value returned by the last synchronous command. */ volatile int last_command_exit_value; /* Whether or not the last command (corresponding to last_command_exit_value) was terminated by a signal, and, if so, which one. */ int last_command_exit_signal; /* Are we currently ignoring the -e option for the duration of a builtin's execution? */ int builtin_ignoring_errexit = 0; /* The list of redirections to perform which will undo the redirections that I made in the shell. */ REDIRECT *redirection_undo_list = (REDIRECT *)NULL; /* The list of redirections to perform which will undo the internal redirections performed by the `exec' builtin. These are redirections that must be undone even when exec discards redirection_undo_list. */ REDIRECT *exec_redirection_undo_list = (REDIRECT *)NULL; /* When greater than zero, value is the `level' of builtins we are currently executing (e.g. `eval echo a' would have it set to 2). */ int executing_builtin = 0; /* Non-zero if we are executing a command list (a;b;c, etc.) */ int executing_list = 0; /* Non-zero if failing commands in a command substitution should not exit the shell even if -e is set. Used to pass the CMD_IGNORE_RETURN flag down to commands run in command substitutions by parse_and_execute. */ int comsub_ignore_return = 0; /* Non-zero if we have just forked and are currently running in a subshell environment. */ int subshell_environment; /* Count of nested subshells, like SHLVL. Available via $BASH_SUBSHELL */ int subshell_level = 0; /* Currently-executing shell function. */ SHELL_VAR *this_shell_function; /* If non-zero, matches in case and [[ ... ]] are case-insensitive */ int match_ignore_case = 0; int executing_command_builtin = 0; struct stat SB; /* used for debugging */ static int special_builtin_failed; static COMMAND *currently_executing_command; /* The line number that the currently executing function starts on. */ static int function_line_number; /* XXX - set to 1 if we're running the DEBUG trap and we want to show the line number containing the function name. Used by executing_line_number to report the correct line number. Kind of a hack. */ static int showing_function_line; static int connection_count; /* $LINENO ($BASH_LINENO) for use by an ERR trap. Global so parse_and_execute can save and restore it. */ int line_number_for_err_trap; /* A convenience macro to avoid resetting line_number_for_err_trap while running the ERR trap. */ #define SET_LINE_NUMBER(v) \ do { \ line_number = v; \ if (signal_in_progress (ERROR_TRAP) == 0 && running_trap != (ERROR_TRAP + 1)) \ line_number_for_err_trap = line_number; \ } while (0) /* This can't be in executing_line_number() because that's used for LINENO and we want LINENO to reflect the line number of commands run during the ERR trap. Right now this is only used to push to BASH_LINENO. */ #define GET_LINE_NUMBER() \ (signal_in_progress (ERROR_TRAP) && running_trap == ERROR_TRAP+1) \ ? line_number_for_err_trap \ : executing_line_number () /* A sort of function nesting level counter */ int funcnest = 0; int funcnest_max = 0; int evalnest = 0; int evalnest_max = EVALNEST_MAX; int sourcenest = 0; int sourcenest_max = SOURCENEST_MAX; volatile int from_return_trap = 0; int lastpipe_opt = 0; struct fd_bitmap *current_fds_to_close = (struct fd_bitmap *)NULL; #define FD_BITMAP_DEFAULT_SIZE 32 /* Functions to allocate and deallocate the structures used to pass information from the shell to its children about file descriptors to close. */ struct fd_bitmap * new_fd_bitmap (size) int size; { struct fd_bitmap *ret; ret = (struct fd_bitmap *)xmalloc (sizeof (struct fd_bitmap)); ret->size = size; if (size) { ret->bitmap = (char *)xmalloc (size); memset (ret->bitmap, '\0', size); } else ret->bitmap = (char *)NULL; return (ret); } void dispose_fd_bitmap (fdbp) struct fd_bitmap *fdbp; { FREE (fdbp->bitmap); free (fdbp); } void close_fd_bitmap (fdbp) struct fd_bitmap *fdbp; { register int i; if (fdbp) { for (i = 0; i < fdbp->size; i++) if (fdbp->bitmap[i]) { close (i); fdbp->bitmap[i] = 0; } } } /* Return the line number of the currently executing command. */ int executing_line_number () { if (executing && showing_function_line == 0 && (variable_context == 0 || interactive_shell == 0) && currently_executing_command) { #if defined (COND_COMMAND) if (currently_executing_command->type == cm_cond) return currently_executing_command->value.Cond->line; #endif #if defined (DPAREN_ARITHMETIC) if (currently_executing_command->type == cm_arith) return currently_executing_command->value.Arith->line; #endif #if defined (ARITH_FOR_COMMAND) if (currently_executing_command->type == cm_arith_for) return currently_executing_command->value.ArithFor->line; #endif return line_number; } else return line_number; } /* Execute the command passed in COMMAND. COMMAND is exactly what read_command () places into GLOBAL_COMMAND. See "command.h" for the details of the command structure. EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible return values. Executing a command with nothing in it returns EXECUTION_SUCCESS. */ int execute_command (command) COMMAND *command; { struct fd_bitmap *bitmap; int result; current_fds_to_close = (struct fd_bitmap *)NULL; bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE); begin_unwind_frame ("execute-command"); add_unwind_protect (dispose_fd_bitmap, (char *)bitmap); /* Just do the command, but not asynchronously. */ result = execute_command_internal (command, 0, NO_PIPE, NO_PIPE, bitmap); dispose_fd_bitmap (bitmap); discard_unwind_frame ("execute-command"); #if defined (PROCESS_SUBSTITUTION) /* don't unlink fifos if we're in a shell function; wait until the function returns. */ if (variable_context == 0 && executing_list == 0) unlink_fifo_list (); #endif /* PROCESS_SUBSTITUTION */ QUIT; return (result); } /* Return 1 if TYPE is a shell control structure type. */ static int shell_control_structure (type) enum command_type type; { switch (type) { #if defined (ARITH_FOR_COMMAND) case cm_arith_for: #endif #if defined (SELECT_COMMAND) case cm_select: #endif #if defined (DPAREN_ARITHMETIC) case cm_arith: #endif #if defined (COND_COMMAND) case cm_cond: #endif case cm_case: case cm_while: case cm_until: case cm_if: case cm_for: case cm_group: case cm_function_def: return (1); default: return (0); } } /* A function to use to unwind_protect the redirection undo list for loops. */ static void cleanup_redirects (list) REDIRECT *list; { do_redirections (list, RX_ACTIVE); dispose_redirects (list); } void undo_partial_redirects () { if (redirection_undo_list) { cleanup_redirects (redirection_undo_list); redirection_undo_list = (REDIRECT *)NULL; } } #if 0 /* Function to unwind_protect the redirections for functions and builtins. */ static void cleanup_func_redirects (list) REDIRECT *list; { do_redirections (list, RX_ACTIVE); } #endif void dispose_exec_redirects () { if (exec_redirection_undo_list) { dispose_redirects (exec_redirection_undo_list); exec_redirection_undo_list = (REDIRECT *)NULL; } } void dispose_partial_redirects () { if (redirection_undo_list) { dispose_redirects (redirection_undo_list); redirection_undo_list = (REDIRECT *)NULL; } } #if defined (JOB_CONTROL) /* A function to restore the signal mask to its proper value when the shell is interrupted or errors occur while creating a pipeline. */ static int restore_signal_mask (set) sigset_t *set; { return (sigprocmask (SIG_SETMASK, set, (sigset_t *)NULL)); } #endif /* JOB_CONTROL */ #ifdef DEBUG /* A debugging function that can be called from gdb, for instance. */ void open_files (void) { register int i; int f, fd_table_size; fd_table_size = getdtablesize (); fprintf (stderr, "pid %ld open files:", (long)getpid ()); for (i = 3; i < fd_table_size; i++) { if ((f = fcntl (i, F_GETFD, 0)) != -1) fprintf (stderr, " %d (%s)", i, f ? "close" : "open"); } fprintf (stderr, "\n"); } #endif void async_redirect_stdin () { int fd; fd = open ("/dev/null", O_RDONLY); if (fd > 0) { dup2 (fd, 0); close (fd); } else if (fd < 0) internal_error (_("cannot redirect standard input from /dev/null: %s"), strerror (errno)); } #define DESCRIBE_PID(pid) do { if (interactive) describe_pid (pid); } while (0) /* Execute the command passed in COMMAND, perhaps doing it asynchronously. COMMAND is exactly what read_command () places into GLOBAL_COMMAND. ASYNCHRONOUS, if non-zero, says to do this command in the background. PIPE_IN and PIPE_OUT are file descriptors saying where input comes from and where it goes. They can have the value of NO_PIPE, which means I/O is stdin/stdout. FDS_TO_CLOSE is a list of file descriptors to close once the child has been forked. This list often contains the unusable sides of pipes, etc. EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible return values. Executing a command with nothing in it returns EXECUTION_SUCCESS. */ int execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close) COMMAND *command; int asynchronous; int pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { int exec_result, user_subshell, invert, ignore_return, was_error_trap, fork_flags; REDIRECT *my_undo_list, *exec_undo_list; char *tcmd; volatile int save_line_number; #if defined (PROCESS_SUBSTITUTION) volatile int ofifo, nfifo, osize, saved_fifo; volatile void *ofifo_list; #endif if (breaking || continuing) return (last_command_exit_value); if (read_but_dont_execute) return (last_command_exit_value); if (command == 0) return (EXECUTION_SUCCESS); QUIT; run_pending_traps (); #if 0 if (running_trap == 0) #endif currently_executing_command = command; invert = (command->flags & CMD_INVERT_RETURN) != 0; /* If we're inverting the return value and `set -e' has been executed, we don't want a failing command to inadvertently cause the shell to exit. */ if (exit_immediately_on_error && invert) /* XXX */ command->flags |= CMD_IGNORE_RETURN; /* XXX */ exec_result = EXECUTION_SUCCESS; /* If a command was being explicitly run in a subshell, or if it is a shell control-structure, and it has a pipe, then we do the command in a subshell. */ if (command->type == cm_subshell && (command->flags & CMD_NO_FORK)) return (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close)); #if defined (COPROCESS_SUPPORT) if (command->type == cm_coproc) return (last_command_exit_value = execute_coproc (command, pipe_in, pipe_out, fds_to_close)); #endif user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0); #if defined (TIME_BEFORE_SUBSHELL) if ((command->flags & CMD_TIME_PIPELINE) && user_subshell && asynchronous == 0) { command->flags |= CMD_FORCE_SUBSHELL; exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close); currently_executing_command = (COMMAND *)NULL; return (exec_result); } #endif if (command->type == cm_subshell || (command->flags & (CMD_WANT_SUBSHELL|CMD_FORCE_SUBSHELL)) || (shell_control_structure (command->type) && (pipe_out != NO_PIPE || pipe_in != NO_PIPE || asynchronous))) { pid_t paren_pid; int s; char *p; /* Fork a subshell, turn off the subshell bit, turn off job control and call execute_command () on the command again. */ save_line_number = line_number; if (command->type == cm_subshell) SET_LINE_NUMBER (command->value.Subshell->line); /* XXX - save value? */ /* Otherwise we defer setting line_number */ tcmd = make_command_string (command); fork_flags = asynchronous ? FORK_ASYNC : 0; paren_pid = make_child (p = savestring (tcmd), fork_flags); if (user_subshell && signal_is_trapped (ERROR_TRAP) && signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } if (paren_pid == 0) { #if defined (JOB_CONTROL) FREE (p); /* child doesn't use pointer */ #endif /* We want to run the exit trap for forced {} subshells, and we want to note this before execute_in_subshell modifies the COMMAND struct. Need to keep in mind that execute_in_subshell runs the exit trap for () subshells itself. */ /* This handles { command; } & */ s = user_subshell == 0 && command->type == cm_group && pipe_in == NO_PIPE && pipe_out == NO_PIPE && asynchronous; /* run exit trap for : | { ...; } and { ...; } | : */ /* run exit trap for : | ( ...; ) and ( ...; ) | : */ s += user_subshell == 0 && command->type == cm_group && (pipe_in != NO_PIPE || pipe_out != NO_PIPE) && asynchronous == 0; last_command_exit_value = execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close); if (s) subshell_exit (last_command_exit_value); else sh_exit (last_command_exit_value); /* NOTREACHED */ } else { close_pipes (pipe_in, pipe_out); #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD) if (variable_context == 0) /* wait until shell function completes */ unlink_fifo_list (); #endif /* If we are part of a pipeline, and not the end of the pipeline, then we should simply return and let the last command in the pipe be waited for. If we are not in a pipeline, or are the last command in the pipeline, then we wait for the subshell and return its exit status as usual. */ if (pipe_out != NO_PIPE) return (EXECUTION_SUCCESS); stop_pipeline (asynchronous, (COMMAND *)NULL); line_number = save_line_number; if (asynchronous == 0) { was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0; invert = (command->flags & CMD_INVERT_RETURN) != 0; ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; exec_result = wait_for (paren_pid, 0); /* If we have to, invert the return value. */ if (invert) exec_result = ((exec_result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS); last_command_exit_value = exec_result; if (user_subshell && was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS) { save_line_number = line_number; line_number = line_number_for_err_trap; run_error_trap (); line_number = save_line_number; } if (user_subshell && ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS) { run_pending_traps (); jump_to_top_level (ERREXIT); } return (last_command_exit_value); } else { DESCRIBE_PID (paren_pid); run_pending_traps (); /* Posix 2013 2.9.3.1: "the exit status of an asynchronous list shall be zero." */ last_command_exit_value = 0; return (EXECUTION_SUCCESS); } } } #if defined (COMMAND_TIMING) if (command->flags & CMD_TIME_PIPELINE) { if (asynchronous) { command->flags |= CMD_FORCE_SUBSHELL; exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close); } else { exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close); #if 0 if (running_trap == 0) #endif currently_executing_command = (COMMAND *)NULL; } return (exec_result); } #endif /* COMMAND_TIMING */ if (shell_control_structure (command->type) && command->redirects) stdin_redir = stdin_redirects (command->redirects); #if defined (PROCESS_SUBSTITUTION) # if !defined (HAVE_DEV_FD) reap_procsubs (); # endif /* XXX - also if sourcelevel != 0? */ if (variable_context != 0 || executing_list) { ofifo = num_fifos (); ofifo_list = copy_fifo_list ((int *)&osize); begin_unwind_frame ("internal_fifos"); if (ofifo_list) add_unwind_protect (xfree, ofifo_list); saved_fifo = 1; } else saved_fifo = 0; #endif /* Handle WHILE FOR CASE etc. with redirections. (Also '&' input redirection.) */ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0; ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; if (do_redirections (command->redirects, RX_ACTIVE|RX_UNDOABLE) != 0) { undo_partial_redirects (); dispose_exec_redirects (); #if defined (PROCESS_SUBSTITUTION) if (saved_fifo) { free ((void *)ofifo_list); discard_unwind_frame ("internal_fifos"); } #endif /* Handle redirection error as command failure if errexit set. */ last_command_exit_value = EXECUTION_FAILURE; if (ignore_return == 0 && invert == 0 && pipe_in == NO_PIPE && pipe_out == NO_PIPE) { if (was_error_trap) { save_line_number = line_number; line_number = line_number_for_err_trap; run_error_trap (); line_number = save_line_number; } if (exit_immediately_on_error) { run_pending_traps (); jump_to_top_level (ERREXIT); } } return (last_command_exit_value); } my_undo_list = redirection_undo_list; redirection_undo_list = (REDIRECT *)NULL; exec_undo_list = exec_redirection_undo_list; exec_redirection_undo_list = (REDIRECT *)NULL; if (my_undo_list || exec_undo_list) begin_unwind_frame ("loop_redirections"); if (my_undo_list) add_unwind_protect ((Function *)cleanup_redirects, my_undo_list); if (exec_undo_list) add_unwind_protect ((Function *)dispose_redirects, exec_undo_list); QUIT; switch (command->type) { case cm_simple: { save_line_number = line_number; /* We can't rely on variables retaining their values across a call to execute_simple_command if a longjmp occurs as the result of a `return' builtin. This is true for sure with gcc. */ #if defined (RECYCLES_PIDS) last_made_pid = NO_PID; #endif was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0; if (ignore_return && command->value.Simple) command->value.Simple->flags |= CMD_IGNORE_RETURN; if (command->flags & CMD_STDIN_REDIR) command->value.Simple->flags |= CMD_STDIN_REDIR; SET_LINE_NUMBER (command->value.Simple->line); exec_result = execute_simple_command (command->value.Simple, pipe_in, pipe_out, asynchronous, fds_to_close); line_number = save_line_number; /* The temporary environment should be used for only the simple command immediately following its definition. */ dispose_used_env_vars (); #if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA) /* Reclaim memory allocated with alloca () on machines which may be using the alloca emulation code. */ (void) alloca (0); #endif /* (ultrix && mips) || C_ALLOCA */ /* If we forked to do the command, then we must wait_for () the child. */ /* XXX - this is something to watch out for if there are problems when the shell is compiled without job control. Don't worry about whether or not last_made_pid == last_pid; already_making_children tells us whether or not there are unwaited-for children to wait for and reap. */ if (already_making_children && pipe_out == NO_PIPE) { stop_pipeline (asynchronous, (COMMAND *)NULL); if (asynchronous) { DESCRIBE_PID (last_made_pid); exec_result = EXECUTION_SUCCESS; invert = 0; /* async commands always succeed */ } else #if !defined (JOB_CONTROL) /* Do not wait for asynchronous processes started from startup files. */ if (last_made_pid != NO_PID && last_made_pid != last_asynchronous_pid) #else if (last_made_pid != NO_PID) #endif /* When executing a shell function that executes other commands, this causes the last simple command in the function to be waited for twice. This also causes subshells forked to execute builtin commands (e.g., in pipelines) to be waited for twice. */ exec_result = wait_for (last_made_pid, 0); } } /* 2009/02/13 -- pipeline failure is processed elsewhere. This handles only the failure of a simple command. We don't want to run the error trap if the command run by the `command' builtin fails; we want to defer that until the command builtin itself returns failure. */ /* 2020/07/14 -- this changes with how the command builtin is handled */ if (was_error_trap && ignore_return == 0 && invert == 0 && pipe_in == NO_PIPE && pipe_out == NO_PIPE && (command->value.Simple->flags & CMD_COMMAND_BUILTIN) == 0 && exec_result != EXECUTION_SUCCESS) { last_command_exit_value = exec_result; line_number = line_number_for_err_trap; run_error_trap (); line_number = save_line_number; } if (ignore_return == 0 && invert == 0 && ((posixly_correct && interactive == 0 && special_builtin_failed) || (exit_immediately_on_error && pipe_in == NO_PIPE && pipe_out == NO_PIPE && exec_result != EXECUTION_SUCCESS))) { last_command_exit_value = exec_result; run_pending_traps (); /* Undo redirections before running exit trap on the way out of set -e. Report by Mark Farrell 5/19/2014 */ if (exit_immediately_on_error && signal_is_trapped (0) && unwind_protect_tag_on_stack ("saved-redirects")) run_unwind_frame ("saved-redirects"); jump_to_top_level (ERREXIT); } break; case cm_for: if (ignore_return) command->value.For->flags |= CMD_IGNORE_RETURN; exec_result = execute_for_command (command->value.For); break; #if defined (ARITH_FOR_COMMAND) case cm_arith_for: if (ignore_return) command->value.ArithFor->flags |= CMD_IGNORE_RETURN; exec_result = execute_arith_for_command (command->value.ArithFor); break; #endif #if defined (SELECT_COMMAND) case cm_select: if (ignore_return) command->value.Select->flags |= CMD_IGNORE_RETURN; exec_result = execute_select_command (command->value.Select); break; #endif case cm_case: if (ignore_return) command->value.Case->flags |= CMD_IGNORE_RETURN; exec_result = execute_case_command (command->value.Case); break; case cm_while: if (ignore_return) command->value.While->flags |= CMD_IGNORE_RETURN; exec_result = execute_while_command (command->value.While); break; case cm_until: if (ignore_return) command->value.While->flags |= CMD_IGNORE_RETURN; exec_result = execute_until_command (command->value.While); break; case cm_if: if (ignore_return) command->value.If->flags |= CMD_IGNORE_RETURN; exec_result = execute_if_command (command->value.If); break; case cm_group: /* This code can be executed from either of two paths: an explicit '{}' command, or via a function call. If we are executed via a function call, we have already taken care of the function being executed in the background (down there in execute_simple_command ()), and this command should *not* be marked as asynchronous. If we are executing a regular '{}' group command, and asynchronous == 1, we must want to execute the whole command in the background, so we need a subshell, and we want the stuff executed in that subshell (this group command) to be executed in the foreground of that subshell (i.e. there will not be *another* subshell forked). What we do is to force a subshell if asynchronous, and then call execute_command_internal again with asynchronous still set to 1, but with the original group command, so the printed command will look right. The code above that handles forking off subshells will note that both subshell and async are on, and turn off async in the child after forking the subshell (but leave async set in the parent, so the normal call to describe_pid is made). This turning off async is *crucial*; if it is not done, this will fall into an infinite loop of executions through this spot in subshell after subshell until the process limit is exhausted. */ if (asynchronous) { command->flags |= CMD_FORCE_SUBSHELL; exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close); } else { if (ignore_return && command->value.Group->command) command->value.Group->command->flags |= CMD_IGNORE_RETURN; exec_result = execute_command_internal (command->value.Group->command, asynchronous, pipe_in, pipe_out, fds_to_close); } break; case cm_connection: exec_result = execute_connection (command, asynchronous, pipe_in, pipe_out, fds_to_close); if (asynchronous) invert = 0; /* XXX */ break; #if defined (DPAREN_ARITHMETIC) case cm_arith: #endif #if defined (COND_COMMAND) case cm_cond: #endif case cm_function_def: was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0; #if defined (DPAREN_ARITHMETIC) if (ignore_return && command->type == cm_arith) command->value.Arith->flags |= CMD_IGNORE_RETURN; #endif #if defined (COND_COMMAND) if (ignore_return && command->type == cm_cond) command->value.Cond->flags |= CMD_IGNORE_RETURN; #endif line_number_for_err_trap = save_line_number = line_number; /* XXX */ #if defined (DPAREN_ARITHMETIC) if (command->type == cm_arith) exec_result = execute_arith_command (command->value.Arith); else #endif #if defined (COND_COMMAND) if (command->type == cm_cond) exec_result = execute_cond_command (command->value.Cond); else #endif if (command->type == cm_function_def) exec_result = execute_intern_function (command->value.Function_def->name, command->value.Function_def); line_number = save_line_number; if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS) { last_command_exit_value = exec_result; save_line_number = line_number; line_number = line_number_for_err_trap; run_error_trap (); line_number = save_line_number; } if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS) { last_command_exit_value = exec_result; run_pending_traps (); jump_to_top_level (ERREXIT); } break; default: command_error ("execute_command", CMDERR_BADTYPE, command->type, 0); } if (my_undo_list) cleanup_redirects (my_undo_list); if (exec_undo_list) dispose_redirects (exec_undo_list); if (my_undo_list || exec_undo_list) discard_unwind_frame ("loop_redirections"); #if defined (PROCESS_SUBSTITUTION) if (saved_fifo) { nfifo = num_fifos (); if (nfifo > ofifo) close_new_fifos ((void *)ofifo_list, osize); free ((void *)ofifo_list); discard_unwind_frame ("internal_fifos"); } #endif /* Invert the return value if we have to */ if (invert) exec_result = (exec_result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS; #if defined (DPAREN_ARITHMETIC) || defined (COND_COMMAND) /* This is where we set PIPESTATUS from the exit status of the appropriate compound commands (the ones that look enough like simple commands to cause confusion). We might be able to optimize by not doing this if subshell_environment != 0. */ switch (command->type) { # if defined (DPAREN_ARITHMETIC) case cm_arith: # endif # if defined (COND_COMMAND) case cm_cond: # endif set_pipestatus_from_exit (exec_result); break; default: break; } #endif last_command_exit_value = exec_result; run_pending_traps (); currently_executing_command = (COMMAND *)NULL; return (last_command_exit_value); } #if defined (COMMAND_TIMING) #if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY) extern struct timeval *difftimeval PARAMS((struct timeval *, struct timeval *, struct timeval *)); extern struct timeval *addtimeval PARAMS((struct timeval *, struct timeval *, struct timeval *)); extern int timeval_to_cpu PARAMS((struct timeval *, struct timeval *, struct timeval *)); #endif #define POSIX_TIMEFORMAT "real %2R\nuser %2U\nsys %2S" #define BASH_TIMEFORMAT "\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS" static const int precs[] = { 0, 100, 10, 1 }; /* Expand one `%'-prefixed escape sequence from a time format string. */ static int mkfmt (buf, prec, lng, sec, sec_fraction) char *buf; int prec, lng; time_t sec; int sec_fraction; { time_t min; char abuf[INT_STRLEN_BOUND(time_t) + 1]; int ind, aind; ind = 0; abuf[sizeof(abuf) - 1] = '\0'; /* If LNG is non-zero, we want to decompose SEC into minutes and seconds. */ if (lng) { min = sec / 60; sec %= 60; aind = sizeof(abuf) - 2; do abuf[aind--] = (min % 10) + '0'; while (min /= 10); aind++; while (abuf[aind]) buf[ind++] = abuf[aind++]; buf[ind++] = 'm'; } /* Now add the seconds. */ aind = sizeof (abuf) - 2; do abuf[aind--] = (sec % 10) + '0'; while (sec /= 10); aind++; while (abuf[aind]) buf[ind++] = abuf[aind++]; /* We want to add a decimal point and PREC places after it if PREC is nonzero. PREC is not greater than 3. SEC_FRACTION is between 0 and 999. */ if (prec != 0) { buf[ind++] = locale_decpoint (); for (aind = 1; aind <= prec; aind++) { buf[ind++] = (sec_fraction / precs[aind]) + '0'; sec_fraction %= precs[aind]; } } if (lng) buf[ind++] = 's'; buf[ind] = '\0'; return (ind); } /* Interpret the format string FORMAT, interpolating the following escape sequences: %[prec][l][RUS] where the optional `prec' is a precision, meaning the number of characters after the decimal point, the optional `l' means to format using minutes and seconds (MMmNN[.FF]s), like the `times' builtin', and the last character is one of R number of seconds of `real' time U number of seconds of `user' time S number of seconds of `system' time An occurrence of `%%' in the format string is translated to a `%'. The result is printed to FP, a pointer to a FILE. The other variables are the seconds and thousandths of a second of real, user, and system time, resectively. */ static void print_formatted_time (fp, format, rs, rsf, us, usf, ss, ssf, cpu) FILE *fp; char *format; time_t rs; int rsf; time_t us; int usf; time_t ss; int ssf, cpu; { int prec, lng, len; char *str, *s, ts[INT_STRLEN_BOUND (time_t) + sizeof ("mSS.FFFF")]; time_t sum; int sum_frac; int sindex, ssize; len = strlen (format); ssize = (len + 64) - (len % 64); str = (char *)xmalloc (ssize); sindex = 0; for (s = format; *s; s++) { if (*s != '%' || s[1] == '\0') { RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64); str[sindex++] = *s; } else if (s[1] == '%') { s++; RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64); str[sindex++] = *s; } else if (s[1] == 'P') { s++; #if 0 /* clamp CPU usage at 100% */ if (cpu > 10000) cpu = 10000; #endif sum = cpu / 100; sum_frac = (cpu % 100) * 10; len = mkfmt (ts, 2, 0, sum, sum_frac); RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64); strcpy (str + sindex, ts); sindex += len; } else { prec = 3; /* default is three places past the decimal point. */ lng = 0; /* default is to not use minutes or append `s' */ s++; if (DIGIT (*s)) /* `precision' */ { prec = *s++ - '0'; if (prec > 3) prec = 3; } if (*s == 'l') /* `length extender' */ { lng = 1; s++; } if (*s == 'R' || *s == 'E') len = mkfmt (ts, prec, lng, rs, rsf); else if (*s == 'U') len = mkfmt (ts, prec, lng, us, usf); else if (*s == 'S') len = mkfmt (ts, prec, lng, ss, ssf); else { internal_error (_("TIMEFORMAT: `%c': invalid format character"), *s); free (str); return; } RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64); strcpy (str + sindex, ts); sindex += len; } } str[sindex] = '\0'; fprintf (fp, "%s\n", str); fflush (fp); free (str); } static int time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close) COMMAND *command; int asynchronous, pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { int rv, posix_time, old_flags, nullcmd, code; time_t rs, us, ss; int rsf, usf, ssf; int cpu; char *time_format; volatile procenv_t save_top_level; volatile int old_subshell; #if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY) struct timeval real, user, sys; struct timeval before, after; # if defined (HAVE_STRUCT_TIMEZONE) struct timezone dtz; /* posix doesn't define this */ # endif struct rusage selfb, selfa, kidsb, kidsa; /* a = after, b = before */ #else # if defined (HAVE_TIMES) clock_t tbefore, tafter, real, user, sys; struct tms before, after; # endif #endif #if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY) # if defined (HAVE_STRUCT_TIMEZONE) gettimeofday (&before, &dtz); # else gettimeofday (&before, (void *)NULL); # endif /* !HAVE_STRUCT_TIMEZONE */ getrusage (RUSAGE_SELF, &selfb); getrusage (RUSAGE_CHILDREN, &kidsb); #else # if defined (HAVE_TIMES) tbefore = times (&before); # endif #endif old_subshell = subshell_environment; posix_time = command && (command->flags & CMD_TIME_POSIX); nullcmd = (command == 0) || (command->type == cm_simple && command->value.Simple->words == 0 && command->value.Simple->redirects == 0); if (posixly_correct && nullcmd) { #if defined (HAVE_GETRUSAGE) selfb.ru_utime.tv_sec = kidsb.ru_utime.tv_sec = selfb.ru_stime.tv_sec = kidsb.ru_stime.tv_sec = 0; selfb.ru_utime.tv_usec = kidsb.ru_utime.tv_usec = selfb.ru_stime.tv_usec = kidsb.ru_stime.tv_usec = 0; before = shellstart; #else before.tms_utime = before.tms_stime = before.tms_cutime = before.tms_cstime = 0; tbefore = shell_start_time; #endif } old_flags = command->flags; COPY_PROCENV (top_level, save_top_level); command->flags &= ~(CMD_TIME_PIPELINE|CMD_TIME_POSIX); code = setjmp_nosigs (top_level); if (code == NOT_JUMPED) rv = execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close); COPY_PROCENV (save_top_level, top_level); command->flags = old_flags; /* If we're jumping in a different subshell environment than we started, don't bother printing timing stats, just keep longjmping back to the original top level. */ if (code != NOT_JUMPED && subshell_environment && subshell_environment != old_subshell) sh_longjmp (top_level, code); rs = us = ss = 0; rsf = usf = ssf = cpu = 0; #if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY) # if defined (HAVE_STRUCT_TIMEZONE) gettimeofday (&after, &dtz); # else gettimeofday (&after, (void *)NULL); # endif /* !HAVE_STRUCT_TIMEZONE */ getrusage (RUSAGE_SELF, &selfa); getrusage (RUSAGE_CHILDREN, &kidsa); difftimeval (&real, &before, &after); timeval_to_secs (&real, &rs, &rsf); addtimeval (&user, difftimeval(&after, &selfb.ru_utime, &selfa.ru_utime), difftimeval(&before, &kidsb.ru_utime, &kidsa.ru_utime)); timeval_to_secs (&user, &us, &usf); addtimeval (&sys, difftimeval(&after, &selfb.ru_stime, &selfa.ru_stime), difftimeval(&before, &kidsb.ru_stime, &kidsa.ru_stime)); timeval_to_secs (&sys, &ss, &ssf); cpu = timeval_to_cpu (&real, &user, &sys); #else # if defined (HAVE_TIMES) tafter = times (&after); real = tafter - tbefore; clock_t_to_secs (real, &rs, &rsf); user = (after.tms_utime - before.tms_utime) + (after.tms_cutime - before.tms_cutime); clock_t_to_secs (user, &us, &usf); sys = (after.tms_stime - before.tms_stime) + (after.tms_cstime - before.tms_cstime); clock_t_to_secs (sys, &ss, &ssf); cpu = (real == 0) ? 0 : ((user + sys) * 10000) / real; # else rs = us = ss = 0; rsf = usf = ssf = cpu = 0; # endif #endif if (posix_time) time_format = POSIX_TIMEFORMAT; else if ((time_format = get_string_value ("TIMEFORMAT")) == 0) { if (posixly_correct && nullcmd) time_format = "user\t%2lU\nsys\t%2lS"; else time_format = BASH_TIMEFORMAT; } if (time_format && *time_format) print_formatted_time (stderr, time_format, rs, rsf, us, usf, ss, ssf, cpu); if (code) sh_longjmp (top_level, code); return rv; } #endif /* COMMAND_TIMING */ /* Execute a command that's supposed to be in a subshell. This must be called after make_child and we must be running in the child process. The caller will return or exit() immediately with the value this returns. */ static int execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close) COMMAND *command; int asynchronous; int pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { volatile int user_subshell, user_coproc, invert; int return_code, function_value, should_redir_stdin, ois, result; volatile COMMAND *tcom; USE_VAR(user_subshell); USE_VAR(user_coproc); USE_VAR(invert); USE_VAR(tcom); USE_VAR(asynchronous); subshell_level++; should_redir_stdin = (asynchronous && (command->flags & CMD_STDIN_REDIR) && pipe_in == NO_PIPE && stdin_redirects (command->redirects) == 0); invert = (command->flags & CMD_INVERT_RETURN) != 0; user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0); user_coproc = command->type == cm_coproc; command->flags &= ~(CMD_FORCE_SUBSHELL | CMD_WANT_SUBSHELL | CMD_INVERT_RETURN); /* If a command is asynchronous in a subshell (like ( foo ) & or the special case of an asynchronous GROUP command where the the subshell bit is turned on down in case cm_group: below), turn off `asynchronous', so that two subshells aren't spawned. XXX - asynchronous used to be set to 0 in this block, but that means that setup_async_signals was never run. Now it's set to 0 after subshell_environment is set appropriately and setup_async_signals is run. This seems semantically correct to me. For example, ( foo ) & seems to say ``do the command `foo' in a subshell environment, but don't wait for that subshell to finish'', and "{ foo ; bar ; } &" seems to me to be like functions or builtins in the background, which executed in a subshell environment. I just don't see the need to fork two subshells. */ /* Don't fork again, we are already in a subshell. A `doubly async' shell is not interactive, however. */ if (asynchronous) { #if defined (JOB_CONTROL) /* If a construct like ( exec xxx yyy ) & is given while job control is active, we want to prevent exec from putting the subshell back into the original process group, carefully undoing all the work we just did in make_child. */ original_pgrp = -1; #endif /* JOB_CONTROL */ ois = interactive_shell; interactive_shell = 0; /* This test is to prevent alias expansion by interactive shells that run `(command) &' but to allow scripts that have enabled alias expansion with `shopt -s expand_alias' to continue to expand aliases. */ if (ois != interactive_shell) expand_aliases = expaliases_flag = 0; } /* Subshells are neither login nor interactive. */ login_shell = interactive = 0; /* And we're no longer in a loop. See Posix interp 842 (we are not in the "same execution environment"). */ if (shell_compatibility_level > 44) loop_level = 0; if (user_subshell) { subshell_environment = SUBSHELL_PAREN; /* XXX */ if (asynchronous) subshell_environment |= SUBSHELL_ASYNC; } else { subshell_environment = 0; /* XXX */ if (asynchronous) subshell_environment |= SUBSHELL_ASYNC; if (pipe_in != NO_PIPE || pipe_out != NO_PIPE) subshell_environment |= SUBSHELL_PIPE; if (user_coproc) subshell_environment |= SUBSHELL_COPROC; } QUIT; CHECK_TERMSIG; reset_terminating_signals (); /* in sig.c */ /* Cancel traps, in trap.c. */ /* Reset the signal handlers in the child, but don't free the trap strings. Set a flag noting that we have to free the trap strings if we run trap to change a signal disposition. */ clear_pending_traps (); reset_signal_handlers (); subshell_environment |= SUBSHELL_RESETTRAP; /* Note that signal handlers have been reset, so we should no longer reset the handler and resend trapped signals to ourselves. */ subshell_environment &= ~SUBSHELL_IGNTRAP; /* We are in a subshell, so forget that we are running a trap handler or that the signal handler has changed (we haven't changed it!) */ /* XXX - maybe do this for `real' signals and not ERR/DEBUG/RETURN/EXIT traps? */ if (running_trap > 0) { run_trap_cleanup (running_trap - 1); running_trap = 0; /* XXX - maybe leave this */ } /* Make sure restore_original_signals doesn't undo the work done by make_child to ensure that asynchronous children are immune to SIGINT and SIGQUIT. Turn off asynchronous to make sure more subshells are not spawned. */ if (asynchronous) { setup_async_signals (); asynchronous = 0; } else set_sigint_handler (); #if defined (JOB_CONTROL) set_sigchld_handler (); #endif /* JOB_CONTROL */ /* Delete all traces that there were any jobs running. This is only for subshells. */ without_job_control (); if (fds_to_close) close_fd_bitmap (fds_to_close); do_piping (pipe_in, pipe_out); #if defined (COPROCESS_SUPPORT) coproc_closeall (); #endif #if defined (PROCESS_SUBSTITUTION) clear_fifo_list (); /* XXX- we haven't created any FIFOs */ #endif /* If this is a user subshell, set a flag if stdin was redirected. This is used later to decide whether to redirect fd 0 to /dev/null for async commands in the subshell. This adds more sh compatibility, but I'm not sure it's the right thing to do. Note that an input pipe to a compound command suffices to inhibit the implicit /dev/null redirection for asynchronous commands executed as part of that compound command. */ if (user_subshell) { stdin_redir = stdin_redirects (command->redirects) || pipe_in != NO_PIPE; #if 0 restore_default_signal (EXIT_TRAP); /* XXX - reset_signal_handlers above */ #endif } else if (shell_control_structure (command->type) && pipe_in != NO_PIPE) stdin_redir = 1; /* If this is an asynchronous command (command &), we want to redirect the standard input from /dev/null in the absence of any specific redirection involving stdin. */ if (should_redir_stdin && stdin_redir == 0) async_redirect_stdin (); #if defined (BUFFERED_INPUT) /* In any case, we are not reading our command input from stdin. */ default_buffered_input = -1; #endif /* We can't optimize away forks if one of the commands executed by the subshell sets an exit trap, so we set CMD_NO_FORK for simple commands and set CMD_TRY_OPTIMIZING for simple commands on the right side of an and-or or `;' list to test for optimizing forks when they are executed. */ if (user_subshell && command->type == cm_subshell && (command->flags & (CMD_TIME_PIPELINE|CMD_INVERT_RETURN)) == 0) optimize_subshell_command (command->value.Subshell->command); /* Do redirections, then dispose of them before recursive call. */ if (command->redirects) { if (do_redirections (command->redirects, RX_ACTIVE) != 0) exit (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE); dispose_redirects (command->redirects); command->redirects = (REDIRECT *)NULL; } if (command->type == cm_subshell) tcom = command->value.Subshell->command; else if (user_coproc) tcom = command->value.Coproc->command; else tcom = command; if (command->flags & CMD_TIME_PIPELINE) tcom->flags |= CMD_TIME_PIPELINE; if (command->flags & CMD_TIME_POSIX) tcom->flags |= CMD_TIME_POSIX; /* Make sure the subshell inherits any CMD_IGNORE_RETURN flag. */ if ((command->flags & CMD_IGNORE_RETURN) && tcom != command) tcom->flags |= CMD_IGNORE_RETURN; /* If this is a simple command, tell execute_disk_command that it might be able to get away without forking and simply exec. This means things like ( sleep 10 ) will only cause one fork. If we're timing the command or inverting its return value, however, we cannot do this optimization. */ if ((user_subshell || user_coproc) && (tcom->type == cm_simple || tcom->type == cm_subshell) && ((tcom->flags & CMD_TIME_PIPELINE) == 0) && ((tcom->flags & CMD_INVERT_RETURN) == 0)) { tcom->flags |= CMD_NO_FORK; if (tcom->type == cm_simple) tcom->value.Simple->flags |= CMD_NO_FORK; } invert = (tcom->flags & CMD_INVERT_RETURN) != 0; tcom->flags &= ~CMD_INVERT_RETURN; result = setjmp_nosigs (top_level); /* If we're inside a function while executing this subshell, we need to handle a possible `return'. */ function_value = 0; if (return_catch_flag) function_value = setjmp_nosigs (return_catch); /* If we're going to exit the shell, we don't want to invert the return status. */ if (result == EXITPROG || result == EXITBLTIN) invert = 0, return_code = last_command_exit_value; else if (result) return_code = (last_command_exit_value == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : last_command_exit_value; else if (function_value) return_code = return_catch_value; else return_code = execute_command_internal ((COMMAND *)tcom, asynchronous, NO_PIPE, NO_PIPE, fds_to_close); /* If we are asked to, invert the return value. */ if (invert) return_code = (return_code == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS; /* If we were explicitly placed in a subshell with (), we need to do the `shell cleanup' things, such as running traps[0]. */ if (user_subshell && signal_is_trapped (0)) { last_command_exit_value = return_code; return_code = run_exit_trap (); } #if 0 subshell_level--; /* don't bother, caller will just exit */ #endif return (return_code); /* NOTREACHED */ } #if defined (COPROCESS_SUPPORT) #define COPROC_MAX 16 typedef struct cpelement { struct cpelement *next; struct coproc *coproc; } cpelement_t; typedef struct cplist { struct cpelement *head; struct cpelement *tail; int ncoproc; int lock; } cplist_t; static struct cpelement *cpe_alloc PARAMS((struct coproc *)); static void cpe_dispose PARAMS((struct cpelement *)); static struct cpelement *cpl_add PARAMS((struct coproc *)); static struct cpelement *cpl_delete PARAMS((pid_t)); static void cpl_reap PARAMS((void)); static void cpl_flush PARAMS((void)); static void cpl_closeall PARAMS((void)); static struct cpelement *cpl_search PARAMS((pid_t)); static struct cpelement *cpl_searchbyname PARAMS((const char *)); static void cpl_prune PARAMS((void)); static void coproc_free PARAMS((struct coproc *)); /* Will go away when there is fully-implemented support for multiple coprocs. */ Coproc sh_coproc = { 0, NO_PID, -1, -1, 0, 0, 0, 0, 0 }; cplist_t coproc_list = {0, 0, 0}; /* Functions to manage the list of coprocs */ static struct cpelement * cpe_alloc (cp) Coproc *cp; { struct cpelement *cpe; cpe = (struct cpelement *)xmalloc (sizeof (struct cpelement)); cpe->coproc = cp; cpe->next = (struct cpelement *)0; return cpe; } static void cpe_dispose (cpe) struct cpelement *cpe; { free (cpe); } static struct cpelement * cpl_add (cp) Coproc *cp; { struct cpelement *cpe; cpe = cpe_alloc (cp); if (coproc_list.head == 0) { coproc_list.head = coproc_list.tail = cpe; coproc_list.ncoproc = 0; /* just to make sure */ } else { coproc_list.tail->next = cpe; coproc_list.tail = cpe; } coproc_list.ncoproc++; return cpe; } static struct cpelement * cpl_delete (pid) pid_t pid; { struct cpelement *prev, *p; for (prev = p = coproc_list.head; p; prev = p, p = p->next) if (p->coproc->c_pid == pid) { prev->next = p->next; /* remove from list */ break; } if (p == 0) return 0; /* not found */ INTERNAL_DEBUG (("cpl_delete: deleting %d", pid)); /* Housekeeping in the border cases. */ if (p == coproc_list.head) coproc_list.head = coproc_list.head->next; else if (p == coproc_list.tail) coproc_list.tail = prev; coproc_list.ncoproc--; if (coproc_list.ncoproc == 0) coproc_list.head = coproc_list.tail = 0; else if (coproc_list.ncoproc == 1) coproc_list.tail = coproc_list.head; /* just to make sure */ return (p); } static void cpl_reap () { struct cpelement *p, *next, *nh, *nt; /* Build a new list by removing dead coprocs and fix up the coproc_list pointers when done. */ nh = nt = next = (struct cpelement *)0; for (p = coproc_list.head; p; p = next) { next = p->next; if (p->coproc->c_flags & COPROC_DEAD) { coproc_list.ncoproc--; /* keep running count, fix up pointers later */ INTERNAL_DEBUG (("cpl_reap: deleting %d", p->coproc->c_pid)); coproc_dispose (p->coproc); cpe_dispose (p); } else if (nh == 0) nh = nt = p; else { nt->next = p; nt = nt->next; } } if (coproc_list.ncoproc == 0) coproc_list.head = coproc_list.tail = 0; else { if (nt) nt->next = 0; coproc_list.head = nh; coproc_list.tail = nt; if (coproc_list.ncoproc == 1) coproc_list.tail = coproc_list.head; /* just to make sure */ } } /* Clear out the list of saved statuses */ static void cpl_flush () { struct cpelement *cpe, *p; for (cpe = coproc_list.head; cpe; ) { p = cpe; cpe = cpe->next; coproc_dispose (p->coproc); cpe_dispose (p); } coproc_list.head = coproc_list.tail = 0; coproc_list.ncoproc = 0; } static void cpl_closeall () { struct cpelement *cpe; for (cpe = coproc_list.head; cpe; cpe = cpe->next) coproc_close (cpe->coproc); } static void cpl_fdchk (fd) int fd; { struct cpelement *cpe; for (cpe = coproc_list.head; cpe; cpe = cpe->next) coproc_checkfd (cpe->coproc, fd); } /* Search for PID in the list of coprocs; return the cpelement struct if found. If not found, return NULL. */ static struct cpelement * cpl_search (pid) pid_t pid; { struct cpelement *cpe; for (cpe = coproc_list.head ; cpe; cpe = cpe->next) if (cpe->coproc->c_pid == pid) return cpe; return (struct cpelement *)NULL; } /* Search for the coproc named NAME in the list of coprocs; return the cpelement struct if found. If not found, return NULL. */ static struct cpelement * cpl_searchbyname (name) const char *name; { struct cpelement *cp; for (cp = coproc_list.head ; cp; cp = cp->next) if (STREQ (cp->coproc->c_name, name)) return cp; return (struct cpelement *)NULL; } static pid_t cpl_firstactive () { struct cpelement *cpe; for (cpe = coproc_list.head ; cpe; cpe = cpe->next) if ((cpe->coproc->c_flags & COPROC_DEAD) == 0) return cpe->coproc->c_pid; return (pid_t)NO_PID; } #if 0 static void cpl_prune () { struct cpelement *cp; while (coproc_list.head && coproc_list.ncoproc > COPROC_MAX) { cp = coproc_list.head; coproc_list.head = coproc_list.head->next; coproc_dispose (cp->coproc); cpe_dispose (cp); coproc_list.ncoproc--; } } #endif /* These currently use a single global "shell coproc" but are written in a way to not preclude additional coprocs later (using the list management package above). */ struct coproc * getcoprocbypid (pid) pid_t pid; { #if MULTIPLE_COPROCS struct cpelement *p; p = cpl_search (pid); return (p ? p->coproc : 0); #else return (pid == sh_coproc.c_pid ? &sh_coproc : 0); #endif } struct coproc * getcoprocbyname (name) const char *name; { #if MULTIPLE_COPROCS struct cpelement *p; p = cpl_searchbyname (name); return (p ? p->coproc : 0); #else return ((sh_coproc.c_name && STREQ (sh_coproc.c_name, name)) ? &sh_coproc : 0); #endif } void coproc_init (cp) struct coproc *cp; { cp->c_name = 0; cp->c_pid = NO_PID; cp->c_rfd = cp->c_wfd = -1; cp->c_rsave = cp->c_wsave = -1; cp->c_flags = cp->c_status = cp->c_lock = 0; } struct coproc * coproc_alloc (name, pid) char *name; pid_t pid; { struct coproc *cp; #if MULTIPLE_COPROCS cp = (struct coproc *)xmalloc (sizeof (struct coproc)); #else cp = &sh_coproc; #endif coproc_init (cp); cp->c_lock = 2; cp->c_pid = pid; cp->c_name = savestring (name); #if MULTIPLE_COPROCS cpl_add (cp); #endif cp->c_lock = 0; return (cp); } static void coproc_free (cp) struct coproc *cp; { free (cp); } void coproc_dispose (cp) struct coproc *cp; { sigset_t set, oset; if (cp == 0) return; BLOCK_SIGNAL (SIGCHLD, set, oset); cp->c_lock = 3; coproc_unsetvars (cp); FREE (cp->c_name); coproc_close (cp); #if MULTIPLE_COPROCS coproc_free (cp); #else coproc_init (cp); cp->c_lock = 0; #endif UNBLOCK_SIGNAL (oset); } /* Placeholder for now. Will require changes for multiple coprocs */ void coproc_flush () { #if MULTIPLE_COPROCS cpl_flush (); #else coproc_dispose (&sh_coproc); #endif } void coproc_close (cp) struct coproc *cp; { if (cp->c_rfd >= 0) { close (cp->c_rfd); cp->c_rfd = -1; } if (cp->c_wfd >= 0) { close (cp->c_wfd); cp->c_wfd = -1; } cp->c_rsave = cp->c_wsave = -1; } void coproc_closeall () { #if MULTIPLE_COPROCS cpl_closeall (); #else coproc_close (&sh_coproc); /* XXX - will require changes for multiple coprocs */ #endif } void coproc_reap () { #if MULTIPLE_COPROCS cpl_reap (); #else struct coproc *cp; cp = &sh_coproc; /* XXX - will require changes for multiple coprocs */ if (cp && (cp->c_flags & COPROC_DEAD)) coproc_dispose (cp); #endif } void coproc_rclose (cp, fd) struct coproc *cp; int fd; { if (cp->c_rfd >= 0 && cp->c_rfd == fd) { close (cp->c_rfd); cp->c_rfd = -1; } } void coproc_wclose (cp, fd) struct coproc *cp; int fd; { if (cp->c_wfd >= 0 && cp->c_wfd == fd) { close (cp->c_wfd); cp->c_wfd = -1; } } void coproc_checkfd (cp, fd) struct coproc *cp; int fd; { int update; update = 0; if (cp->c_rfd >= 0 && cp->c_rfd == fd) update = cp->c_rfd = -1; if (cp->c_wfd >= 0 && cp->c_wfd == fd) update = cp->c_wfd = -1; if (update) coproc_setvars (cp); } void coproc_fdchk (fd) int fd; { #if MULTIPLE_COPROCS cpl_fdchk (fd); #else coproc_checkfd (&sh_coproc, fd); #endif } void coproc_fdclose (cp, fd) struct coproc *cp; int fd; { coproc_rclose (cp, fd); coproc_wclose (cp, fd); coproc_setvars (cp); } void coproc_fdsave (cp) struct coproc *cp; { cp->c_rsave = cp->c_rfd; cp->c_wsave = cp->c_wfd; } void coproc_fdrestore (cp) struct coproc *cp; { cp->c_rfd = cp->c_rsave; cp->c_wfd = cp->c_wsave; } static void coproc_setstatus (cp, status) struct coproc *cp; int status; { cp->c_lock = 4; cp->c_status = status; cp->c_flags |= COPROC_DEAD; cp->c_flags &= ~COPROC_RUNNING; /* Don't dispose the coproc or unset the COPROC_XXX variables because this is executed in a signal handler context. Wait until coproc_reap takes care of it. */ cp->c_lock = 0; } void coproc_pidchk (pid, status) pid_t pid; int status; { struct coproc *cp; #if MULTIPLE_COPROCS struct cpelement *cpe; /* We're not disposing the coproc because this is executed in a signal handler context */ cpe = cpl_search (pid); cp = cpe ? cpe->coproc : 0; #else cp = getcoprocbypid (pid); #endif if (cp) coproc_setstatus (cp, status); } pid_t coproc_active () { #if MULTIPLE_COPROCS return (cpl_firstactive ()); #else return ((sh_coproc.c_flags & COPROC_DEAD) ? NO_PID : sh_coproc.c_pid); #endif } void coproc_setvars (cp) struct coproc *cp; { SHELL_VAR *v; char *namevar, *t; size_t l; WORD_DESC w; #if defined (ARRAY_VARS) arrayind_t ind; #endif if (cp->c_name == 0) return; /* We could do more here but right now we only check the name, warn if it's not a valid identifier, and refuse to create variables with invalid names if a coproc with such a name is supplied. */ w.word = cp->c_name; w.flags = 0; if (check_identifier (&w, 1) == 0) return; l = strlen (cp->c_name); namevar = xmalloc (l + 16); #if defined (ARRAY_VARS) v = find_variable (cp->c_name); /* This is the same code as in find_or_make_array_variable */ if (v == 0) { v = find_variable_nameref_for_create (cp->c_name, 1); if (v == INVALID_NAMEREF_VALUE) { free (namevar); return; } if (v && nameref_p (v)) { free (cp->c_name); cp->c_name = savestring (nameref_cell (v)); v = make_new_array_variable (cp->c_name); } } if (v && (readonly_p (v) || noassign_p (v))) { if (readonly_p (v)) err_readonly (cp->c_name); free (namevar); return; } if (v == 0) v = make_new_array_variable (cp->c_name); if (array_p (v) == 0) v = convert_var_to_array (v); t = itos (cp->c_rfd); ind = 0; v = bind_array_variable (cp->c_name, ind, t, 0); free (t); t = itos (cp->c_wfd); ind = 1; v = bind_array_variable (cp->c_name, ind, t, 0); free (t); #else sprintf (namevar, "%s_READ", cp->c_name); t = itos (cp->c_rfd); bind_variable (namevar, t, 0); free (t); sprintf (namevar, "%s_WRITE", cp->c_name); t = itos (cp->c_wfd); bind_variable (namevar, t, 0); free (t); #endif sprintf (namevar, "%s_PID", cp->c_name); t = itos (cp->c_pid); v = bind_variable (namevar, t, 0); free (t); free (namevar); } void coproc_unsetvars (cp) struct coproc *cp; { int l; char *namevar; if (cp->c_name == 0) return; l = strlen (cp->c_name); namevar = xmalloc (l + 16); sprintf (namevar, "%s_PID", cp->c_name); unbind_variable_noref (namevar); #if defined (ARRAY_VARS) check_unbind_variable (cp->c_name); #else sprintf (namevar, "%s_READ", cp->c_name); unbind_variable (namevar); sprintf (namevar, "%s_WRITE", cp->c_name); unbind_variable (namevar); #endif free (namevar); } static int execute_coproc (command, pipe_in, pipe_out, fds_to_close) COMMAND *command; int pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { int rpipe[2], wpipe[2], estat, invert; pid_t coproc_pid; Coproc *cp; char *tcmd, *p, *name; sigset_t set, oset; /* XXX -- can be removed after changes to handle multiple coprocs */ #if !MULTIPLE_COPROCS if (sh_coproc.c_pid != NO_PID && (sh_coproc.c_rfd >= 0 || sh_coproc.c_wfd >= 0)) internal_warning (_("execute_coproc: coproc [%d:%s] still exists"), sh_coproc.c_pid, sh_coproc.c_name); coproc_init (&sh_coproc); #endif invert = (command->flags & CMD_INVERT_RETURN) != 0; /* expand name without splitting - could make this dependent on a shopt option */ name = expand_string_unsplit_to_string (command->value.Coproc->name, 0); /* Optional check -- could be relaxed */ if (legal_identifier (name) == 0) { internal_error (_("`%s': not a valid identifier"), name); free (name); return (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE); } else { free (command->value.Coproc->name); command->value.Coproc->name = name; } command_string_index = 0; tcmd = make_command_string (command); sh_openpipe ((int *)&rpipe); /* 0 = parent read, 1 = child write */ sh_openpipe ((int *)&wpipe); /* 0 = child read, 1 = parent write */ BLOCK_SIGNAL (SIGCHLD, set, oset); coproc_pid = make_child (p = savestring (tcmd), FORK_ASYNC); if (coproc_pid == 0) { close (rpipe[0]); close (wpipe[1]); #if defined (JOB_CONTROL) FREE (p); #endif UNBLOCK_SIGNAL (oset); estat = execute_in_subshell (command, 1, wpipe[0], rpipe[1], fds_to_close); fflush (stdout); fflush (stderr); exit (estat); } close (rpipe[1]); close (wpipe[0]); cp = coproc_alloc (command->value.Coproc->name, coproc_pid); cp->c_rfd = rpipe[0]; cp->c_wfd = wpipe[1]; cp->c_flags |= COPROC_RUNNING; SET_CLOSE_ON_EXEC (cp->c_rfd); SET_CLOSE_ON_EXEC (cp->c_wfd); coproc_setvars (cp); UNBLOCK_SIGNAL (oset); #if 0 itrace ("execute_coproc (%s): [%d] %s", command->value.Coproc->name, coproc_pid, the_printed_command); #endif close_pipes (pipe_in, pipe_out); #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD) unlink_fifo_list (); #endif stop_pipeline (1, (COMMAND *)NULL); DESCRIBE_PID (coproc_pid); run_pending_traps (); return (invert ? EXECUTION_FAILURE : EXECUTION_SUCCESS); } #endif /* If S == -1, it's a special value saying to close stdin */ static void restore_stdin (s) int s; { if (s == -1) close (0); else { dup2 (s, 0); close (s); } } /* Catch-all cleanup function for lastpipe code for unwind-protects */ static void lastpipe_cleanup (s) int s; { set_jobs_list_frozen (s); } static int execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close) COMMAND *command; int asynchronous, pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { int prev, fildes[2], new_bitmap_size, dummyfd, ignore_return, exec_result; int lstdin, lastpipe_flag, lastpipe_jid, old_frozen, stdin_valid; COMMAND *cmd; struct fd_bitmap *fd_bitmap; pid_t lastpid; #if defined (JOB_CONTROL) sigset_t set, oset; BLOCK_CHILD (set, oset); #endif /* JOB_CONTROL */ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; stdin_valid = sh_validfd (0); prev = pipe_in; cmd = command; while (cmd && cmd->type == cm_connection && cmd->value.Connection && cmd->value.Connection->connector == '|') { /* Make a pipeline between the two commands. */ if (pipe (fildes) < 0) { sys_error (_("pipe error")); #if defined (JOB_CONTROL) terminate_current_pipeline (); kill_current_pipeline (); UNBLOCK_CHILD (oset); #endif /* JOB_CONTROL */ last_command_exit_value = EXECUTION_FAILURE; /* The unwind-protects installed below will take care of closing all of the open file descriptors. */ throw_to_top_level (); return (EXECUTION_FAILURE); /* XXX */ } /* Here is a problem: with the new file close-on-exec code, the read end of the pipe (fildes[0]) stays open in the first process, so that process will never get a SIGPIPE. There is no way to signal the first process that it should close fildes[0] after forking, so it remains open. No SIGPIPE is ever sent because there is still a file descriptor open for reading connected to the pipe. We take care of that here. This passes around a bitmap of file descriptors that must be closed after making a child process in execute_simple_command. */ /* We need fd_bitmap to be at least as big as fildes[0]. If fildes[0] is less than fds_to_close->size, then use fds_to_close->size. */ new_bitmap_size = (fildes[0] < fds_to_close->size) ? fds_to_close->size : fildes[0] + 8; fd_bitmap = new_fd_bitmap (new_bitmap_size); /* Now copy the old information into the new bitmap. */ xbcopy ((char *)fds_to_close->bitmap, (char *)fd_bitmap->bitmap, fds_to_close->size); /* And mark the pipe file descriptors to be closed. */ fd_bitmap->bitmap[fildes[0]] = 1; /* In case there are pipe or out-of-processes errors, we want all these file descriptors to be closed when unwind-protects are run, and the storage used for the bitmaps freed up. */ begin_unwind_frame ("pipe-file-descriptors"); add_unwind_protect (dispose_fd_bitmap, fd_bitmap); add_unwind_protect (close_fd_bitmap, fd_bitmap); if (prev >= 0) add_unwind_protect (close, prev); dummyfd = fildes[1]; add_unwind_protect (close, dummyfd); #if defined (JOB_CONTROL) add_unwind_protect (restore_signal_mask, &oset); #endif /* JOB_CONTROL */ if (ignore_return && cmd->value.Connection->first) cmd->value.Connection->first->flags |= CMD_IGNORE_RETURN; execute_command_internal (cmd->value.Connection->first, asynchronous, prev, fildes[1], fd_bitmap); if (prev >= 0) close (prev); prev = fildes[0]; close (fildes[1]); dispose_fd_bitmap (fd_bitmap); discard_unwind_frame ("pipe-file-descriptors"); cmd = cmd->value.Connection->second; } lastpid = last_made_pid; /* Now execute the rightmost command in the pipeline. */ if (ignore_return && cmd) cmd->flags |= CMD_IGNORE_RETURN; lastpipe_flag = 0; begin_unwind_frame ("lastpipe-exec"); lstdin = -2; /* -1 is special, meaning fd 0 is closed */ /* If the `lastpipe' option is set with shopt, and job control is not enabled, execute the last element of non-async pipelines in the current shell environment. */ /* prev can be 0 if fd 0 was closed when this function was executed. prev will never be 0 at this point if fd 0 was valid when this function was executed (though we check above). */ if (lastpipe_opt && job_control == 0 && asynchronous == 0 && pipe_out == NO_PIPE && prev >= 0) { /* -1 is a special value meaning to close stdin */ lstdin = (prev > 0 && stdin_valid) ? move_to_high_fd (0, 1, -1) : -1; if (lstdin > 0 || lstdin == -1) { do_piping (prev, pipe_out); prev = NO_PIPE; add_unwind_protect (restore_stdin, lstdin); lastpipe_flag = 1; old_frozen = freeze_jobs_list (); lastpipe_jid = stop_pipeline (0, (COMMAND *)NULL); /* XXX */ add_unwind_protect (lastpipe_cleanup, old_frozen); #if defined (JOB_CONTROL) UNBLOCK_CHILD (oset); /* XXX */ #endif } if (cmd) cmd->flags |= CMD_LASTPIPE; } if (prev >= 0) add_unwind_protect (close, prev); exec_result = execute_command_internal (cmd, asynchronous, prev, pipe_out, fds_to_close); if (prev >= 0) close (prev); if (lstdin > 0 || lstdin == -1) restore_stdin (lstdin); #if defined (JOB_CONTROL) UNBLOCK_CHILD (oset); #endif QUIT; if (lastpipe_flag) { #if defined (JOB_CONTROL) if (INVALID_JOB (lastpipe_jid) == 0) { append_process (savestring (the_printed_command_except_trap), dollar_dollar_pid, exec_result, lastpipe_jid); lstdin = wait_for (lastpid, 0); } else { lstdin = wait_for_single_pid (lastpid, 0); /* checks bgpids list */ if (lstdin > 256) /* error sentinel */ lstdin = 127; } #else lstdin = wait_for (lastpid, 0); #endif #if defined (JOB_CONTROL) /* If wait_for removes the job from the jobs table, use result of last command as pipeline's exit status as usual. The jobs list can get frozen and unfrozen at inconvenient times if there are multiple pipelines running simultaneously. */ if (INVALID_JOB (lastpipe_jid) == 0) exec_result = job_exit_status (lastpipe_jid); else if (pipefail_opt) exec_result = exec_result | lstdin; /* XXX */ /* otherwise we use exec_result */ #endif set_jobs_list_frozen (old_frozen); } discard_unwind_frame ("lastpipe-exec"); return (exec_result); } static int execute_connection (command, asynchronous, pipe_in, pipe_out, fds_to_close) COMMAND *command; int asynchronous, pipe_in, pipe_out; struct fd_bitmap *fds_to_close; { COMMAND *tc, *second; int ignore_return, exec_result, was_error_trap, invert; volatile int save_line_number; ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; switch (command->value.Connection->connector) { /* Do the first command asynchronously. */ case '&': tc = command->value.Connection->first; if (tc == 0) return (EXECUTION_SUCCESS); if (ignore_return) tc->flags |= CMD_IGNORE_RETURN; tc->flags |= CMD_AMPERSAND; /* If this shell was compiled without job control support, if we are currently in a subshell via `( xxx )', or if job control is not active then the standard input for an asynchronous command is forced to /dev/null. */ #if defined (JOB_CONTROL) if ((subshell_environment || !job_control) && !stdin_redir) #else if (!stdin_redir) #endif /* JOB_CONTROL */ tc->flags |= CMD_STDIN_REDIR; exec_result = execute_command_internal (tc, 1, pipe_in, pipe_out, fds_to_close); QUIT; if (tc->flags & CMD_STDIN_REDIR) tc->flags &= ~CMD_STDIN_REDIR; second = command->value.Connection->second; if (second) { if (ignore_return) second->flags |= CMD_IGNORE_RETURN; exec_result = execute_command_internal (second, asynchronous, pipe_in, pipe_out, fds_to_close); } break; /* Just call execute command on both sides. */ case ';': case '\n': /* special case, happens in command substitutions */ if (ignore_return) { if (command->value.Connection->first) command->value.Connection->first->flags |= CMD_IGNORE_RETURN; if (command->value.Connection->second) command->value.Connection->second->flags |= CMD_IGNORE_RETURN; } executing_list++; QUIT; #if 1 execute_command (command->value.Connection->first); #else execute_command_internal (command->value.Connection->first, asynchronous, pipe_in, pipe_out, fds_to_close); #endif QUIT; optimize_connection_fork (command); /* XXX */ exec_result = execute_command_internal (command->value.Connection->second, asynchronous, pipe_in, pipe_out, fds_to_close); executing_list--; break; case '|': was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0; invert = (command->flags & CMD_INVERT_RETURN) != 0; ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; SET_LINE_NUMBER (line_number); /* XXX - save value? */ exec_result = execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close); if (asynchronous) { exec_result = EXECUTION_SUCCESS; invert = 0; } if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS) { last_command_exit_value = exec_result; save_line_number = line_number; line_number = line_number_for_err_trap; run_error_trap (); line_number = save_line_number; } if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS) { last_command_exit_value = exec_result; run_pending_traps (); jump_to_top_level (ERREXIT); } break; case AND_AND: case OR_OR: if (asynchronous) { /* If we have something like `a && b &' or `a || b &', run the && or || stuff in a subshell. Force a subshell and just call execute_command_internal again. Leave asynchronous on so that we get a report from the parent shell about the background job. */ command->flags |= CMD_FORCE_SUBSHELL; exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close); break; } /* Execute the first command. If the result of that is successful and the connector is AND_AND, or the result is not successful and the connector is OR_OR, then execute the second command, otherwise return. */ executing_list++; if (command->value.Connection->first) command->value.Connection->first->flags |= CMD_IGNORE_RETURN; #if 1 exec_result = execute_command (command->value.Connection->first); #else exec_result = execute_command_internal (command->value.Connection->first, 0, NO_PIPE, NO_PIPE, fds_to_close); #endif QUIT; if (((command->value.Connection->connector == AND_AND) && (exec_result == EXECUTION_SUCCESS)) || ((command->value.Connection->connector == OR_OR) && (exec_result != EXECUTION_SUCCESS))) { optimize_connection_fork (command); second = command->value.Connection->second; if (ignore_return && second) second->flags |= CMD_IGNORE_RETURN; exec_result = execute_command (second); } executing_list--; break; default: command_error ("execute_connection", CMDERR_BADCONN, command->value.Connection->connector, 0); jump_to_top_level (DISCARD); exec_result = EXECUTION_FAILURE; } return exec_result; } /* The test used to be only for interactive_shell, but we don't want to report job status when the shell is not interactive or when job control isn't enabled. */ #define REAP() \ do \ { \ if (job_control == 0 || interactive_shell == 0) \ reap_dead_jobs (); \ } \ while (0) /* Execute a FOR command. The syntax is: FOR word_desc IN word_list; DO command; DONE */ static int execute_for_command (for_command) FOR_COM *for_command; { register WORD_LIST *releaser, *list; SHELL_VAR *v; char *identifier; int retval, save_line_number; #if 0 SHELL_VAR *old_value = (SHELL_VAR *)NULL; /* Remember the old value of x. */ #endif save_line_number = line_number; if (check_identifier (for_command->name, 1) == 0) { if (posixly_correct && interactive_shell == 0) { last_command_exit_value = EX_BADUSAGE; jump_to_top_level (ERREXIT); } return (EXECUTION_FAILURE); } loop_level++; identifier = for_command->name->word; line_number = for_command->line; /* for expansion error messages */ list = releaser = expand_words_no_vars (for_command->map_list); begin_unwind_frame ("for"); add_unwind_protect (dispose_words, releaser); #if 0 if (lexical_scoping) { old_value = copy_variable (find_variable (identifier)); if (old_value) add_unwind_protect (dispose_variable, old_value); } #endif if (for_command->flags & CMD_IGNORE_RETURN) for_command->action->flags |= CMD_IGNORE_RETURN; for (retval = EXECUTION_SUCCESS; list; list = list->next) { QUIT; line_number = for_command->line; /* Remember what this command looks like, for debugger. */ command_string_index = 0; print_for_command_head (for_command); if (echo_command_at_execute) xtrace_print_for_command_head (for_command); /* Save this command unless it's a trap command and we're not running a debug trap. */ if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } retval = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && retval != EXECUTION_SUCCESS) continue; #endif this_command_name = (char *)NULL; /* XXX - special ksh93 for command index variable handling */ v = find_variable_last_nameref (identifier, 1); if (v && nameref_p (v)) { if (valid_nameref_value (list->word->word, 1) == 0) { sh_invalidid (list->word->word); v = 0; } else if (readonly_p (v)) err_readonly (name_cell (v)); else v = bind_variable_value (v, list->word->word, ASS_NAMEREF); } else v = bind_variable (identifier, list->word->word, 0); if (v == 0 || readonly_p (v) || noassign_p (v)) { line_number = save_line_number; if (v && readonly_p (v) && interactive_shell == 0 && posixly_correct) { last_command_exit_value = EXECUTION_FAILURE; jump_to_top_level (FORCE_EOF); } else { dispose_words (releaser); discard_unwind_frame ("for"); loop_level--; return (EXECUTION_FAILURE); } } if (ifsname (identifier)) setifs (v); else stupidly_hack_special_variables (identifier); retval = execute_command (for_command->action); REAP (); QUIT; if (breaking) { breaking--; break; } if (continuing) { continuing--; if (continuing) break; } } loop_level--; line_number = save_line_number; #if 0 if (lexical_scoping) { if (!old_value) unbind_variable (identifier); else { SHELL_VAR *new_value; new_value = bind_variable (identifier, value_cell (old_value), 0); new_value->attributes = old_value->attributes; dispose_variable (old_value); } } #endif dispose_words (releaser); discard_unwind_frame ("for"); return (retval); } #if defined (ARITH_FOR_COMMAND) /* Execute an arithmetic for command. The syntax is for (( init ; step ; test )) do body done The execution should be exactly equivalent to eval \(\( init \)\) while eval \(\( test \)\) ; do body; eval \(\( step \)\) done */ static intmax_t eval_arith_for_expr (l, okp) WORD_LIST *l; int *okp; { WORD_LIST *new; intmax_t expresult; int r, eflag; char *expr, *temp; expr = l->next ? string_list (l) : l->word->word; temp = expand_arith_string (expr, Q_DOUBLE_QUOTES|Q_ARITH); if (l->next) free (expr); new = make_word_list (make_word (temp), (WORD_LIST *)NULL); free (temp); if (new) { if (echo_command_at_execute) xtrace_print_arith_cmd (new); command_string_index = 0; print_arith_command (new); if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } r = run_debug_trap (); /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED; this_command_name = "(("; /* )) for expression error messages */ #if defined (DEBUGGER) if (debugging_mode == 0 || r == EXECUTION_SUCCESS) expresult = evalexp (new->word->word, eflag, okp); else { expresult = 0; if (okp) *okp = 1; } #else expresult = evalexp (new->word->word, eflag, okp); #endif dispose_words (new); } else { expresult = 0; if (okp) *okp = 1; } return (expresult); } static int execute_arith_for_command (arith_for_command) ARITH_FOR_COM *arith_for_command; { intmax_t expresult; int expok, body_status, arith_lineno, save_lineno; body_status = EXECUTION_SUCCESS; loop_level++; save_lineno = line_number; if (arith_for_command->flags & CMD_IGNORE_RETURN) arith_for_command->action->flags |= CMD_IGNORE_RETURN; this_command_name = "(("; /* )) for expression error messages */ /* save the starting line number of the command so we can reset line_number before executing each expression -- for $LINENO and the DEBUG trap. */ line_number = arith_lineno = arith_for_command->line; if (variable_context && interactive_shell && sourcelevel == 0) { /* line numbers in a function start at 1 */ line_number -= function_line_number - 1; if (line_number <= 0) line_number = 1; } /* Evaluate the initialization expression. */ expresult = eval_arith_for_expr (arith_for_command->init, &expok); if (expok == 0) { line_number = save_lineno; return (EXECUTION_FAILURE); } while (1) { /* Evaluate the test expression. */ line_number = arith_lineno; expresult = eval_arith_for_expr (arith_for_command->test, &expok); line_number = save_lineno; if (expok == 0) { body_status = EXECUTION_FAILURE; break; } REAP (); if (expresult == 0) break; /* Execute the body of the arithmetic for command. */ QUIT; body_status = execute_command (arith_for_command->action); QUIT; /* Handle any `break' or `continue' commands executed by the body. */ if (breaking) { breaking--; break; } if (continuing) { continuing--; if (continuing) break; } /* Evaluate the step expression. */ line_number = arith_lineno; expresult = eval_arith_for_expr (arith_for_command->step, &expok); line_number = save_lineno; if (expok == 0) { body_status = EXECUTION_FAILURE; break; } } loop_level--; line_number = save_lineno; return (body_status); } #endif #if defined (SELECT_COMMAND) static int LINES, COLS, tabsize; #define RP_SPACE ") " #define RP_SPACE_LEN 2 /* XXX - does not handle numbers > 1000000 at all. */ #define NUMBER_LEN(s) \ ((s < 10) ? 1 \ : ((s < 100) ? 2 \ : ((s < 1000) ? 3 \ : ((s < 10000) ? 4 \ : ((s < 100000) ? 5 \ : 6))))) static int displen (s) const char *s; { #if defined (HANDLE_MULTIBYTE) wchar_t *wcstr; size_t slen; int wclen; wcstr = 0; slen = mbstowcs (wcstr, s, 0); if (slen == -1) slen = 0; wcstr = (wchar_t *)xmalloc (sizeof (wchar_t) * (slen + 1)); mbstowcs (wcstr, s, slen + 1); wclen = wcswidth (wcstr, slen); free (wcstr); return (wclen < 0 ? STRLEN(s) : wclen); #else return (STRLEN (s)); #endif } static int print_index_and_element (len, ind, list) int len, ind; WORD_LIST *list; { register WORD_LIST *l; register int i; if (list == 0) return (0); for (i = ind, l = list; l && --i; l = l->next) ; if (l == 0) /* don't think this can happen */ return (0); fprintf (stderr, "%*d%s%s", len, ind, RP_SPACE, l->word->word); return (displen (l->word->word)); } static void indent (from, to) int from, to; { while (from < to) { if ((to / tabsize) > (from / tabsize)) { putc ('\t', stderr); from += tabsize - from % tabsize; } else { putc (' ', stderr); from++; } } } static void print_select_list (list, list_len, max_elem_len, indices_len) WORD_LIST *list; int list_len, max_elem_len, indices_len; { int ind, row, elem_len, pos, cols, rows; int first_column_indices_len, other_indices_len; if (list == 0) { putc ('\n', stderr); return; } cols = max_elem_len ? COLS / max_elem_len : 1; if (cols == 0) cols = 1; rows = list_len ? list_len / cols + (list_len % cols != 0) : 1; cols = list_len ? list_len / rows + (list_len % rows != 0) : 1; if (rows == 1) { rows = cols; cols = 1; } first_column_indices_len = NUMBER_LEN (rows); other_indices_len = indices_len; for (row = 0; row < rows; row++) { ind = row; pos = 0; while (1) { indices_len = (pos == 0) ? first_column_indices_len : other_indices_len; elem_len = print_index_and_element (indices_len, ind + 1, list); elem_len += indices_len + RP_SPACE_LEN; ind += rows; if (ind >= list_len) break; indent (pos + elem_len, pos + max_elem_len); pos += max_elem_len; } putc ('\n', stderr); } } /* Print the elements of LIST, one per line, preceded by an index from 1 to LIST_LEN. Then display PROMPT and wait for the user to enter a number. If the number is between 1 and LIST_LEN, return that selection. If EOF is read, return a null string. If a blank line is entered, or an invalid number is entered, the loop is executed again. */ static char * select_query (list, list_len, prompt, print_menu) WORD_LIST *list; int list_len; char *prompt; int print_menu; { int max_elem_len, indices_len, len, r, oe; intmax_t reply; WORD_LIST *l; char *repl_string, *t; COLS = default_columns (); #if 0 t = get_string_value ("TABSIZE"); tabsize = (t && *t) ? atoi (t) : 8; if (tabsize <= 0) tabsize = 8; #else tabsize = 8; #endif max_elem_len = 0; for (l = list; l; l = l->next) { len = displen (l->word->word); if (len > max_elem_len) max_elem_len = len; } indices_len = NUMBER_LEN (list_len); max_elem_len += indices_len + RP_SPACE_LEN + 2; while (1) { if (print_menu) print_select_list (list, list_len, max_elem_len, indices_len); fprintf (stderr, "%s", prompt); fflush (stderr); QUIT; oe = executing_builtin; executing_builtin = 1; r = read_builtin ((WORD_LIST *)NULL); executing_builtin = oe; if (r != EXECUTION_SUCCESS) { putchar ('\n'); return ((char *)NULL); } repl_string = get_string_value ("REPLY"); if (repl_string == 0) return ((char *)NULL); if (*repl_string == 0) { print_menu = 1; continue; } if (legal_number (repl_string, &reply) == 0) return ""; if (reply < 1 || reply > list_len) return ""; for (l = list; l && --reply; l = l->next) ; return (l->word->word); /* XXX - can't be null? */ } } /* Execute a SELECT command. The syntax is: SELECT word IN list DO command_list DONE Only `break' or `return' in command_list will terminate the command. */ static int execute_select_command (select_command) SELECT_COM *select_command; { WORD_LIST *releaser, *list; SHELL_VAR *v; char *identifier, *ps3_prompt, *selection; int retval, list_len, show_menu, save_line_number; if (check_identifier (select_command->name, 1) == 0) return (EXECUTION_FAILURE); save_line_number = line_number; line_number = select_command->line; command_string_index = 0; print_select_command_head (select_command); if (echo_command_at_execute) xtrace_print_select_command_head (select_command); #if 0 if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0))) #else if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) #endif { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } retval = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && retval != EXECUTION_SUCCESS) return (EXECUTION_SUCCESS); #endif this_command_name = (char *)0; loop_level++; identifier = select_command->name->word; /* command and arithmetic substitution, parameter and variable expansion, word splitting, pathname expansion, and quote removal. */ list = releaser = expand_words_no_vars (select_command->map_list); list_len = list_length (list); if (list == 0 || list_len == 0) { if (list) dispose_words (list); line_number = save_line_number; return (EXECUTION_SUCCESS); } begin_unwind_frame ("select"); add_unwind_protect (dispose_words, releaser); if (select_command->flags & CMD_IGNORE_RETURN) select_command->action->flags |= CMD_IGNORE_RETURN; retval = EXECUTION_SUCCESS; show_menu = 1; while (1) { line_number = select_command->line; ps3_prompt = get_string_value ("PS3"); if (ps3_prompt == 0) ps3_prompt = "#? "; QUIT; selection = select_query (list, list_len, ps3_prompt, show_menu); QUIT; if (selection == 0) { /* select_query returns EXECUTION_FAILURE if the read builtin fails, so we want to return failure in this case. */ retval = EXECUTION_FAILURE; break; } v = bind_variable (identifier, selection, 0); if (v == 0 || readonly_p (v) || noassign_p (v)) { if (v && readonly_p (v) && interactive_shell == 0 && posixly_correct) { last_command_exit_value = EXECUTION_FAILURE; jump_to_top_level (FORCE_EOF); } else { dispose_words (releaser); discard_unwind_frame ("select"); loop_level--; line_number = save_line_number; return (EXECUTION_FAILURE); } } stupidly_hack_special_variables (identifier); retval = execute_command (select_command->action); REAP (); QUIT; if (breaking) { breaking--; break; } if (continuing) { continuing--; if (continuing) break; } #if defined (KSH_COMPATIBLE_SELECT) show_menu = 0; selection = get_string_value ("REPLY"); if (selection && *selection == '\0') show_menu = 1; #endif } loop_level--; line_number = save_line_number; dispose_words (releaser); discard_unwind_frame ("select"); return (retval); } #endif /* SELECT_COMMAND */ /* Execute a CASE command. The syntax is: CASE word_desc IN pattern_list ESAC. The pattern_list is a linked list of pattern clauses; each clause contains some patterns to compare word_desc against, and an associated command to execute. */ static int execute_case_command (case_command) CASE_COM *case_command; { register WORD_LIST *list; WORD_LIST *wlist, *es; PATTERN_LIST *clauses; char *word, *pattern; int retval, match, ignore_return, save_line_number, qflags; save_line_number = line_number; line_number = case_command->line; command_string_index = 0; print_case_command_head (case_command); if (echo_command_at_execute) xtrace_print_case_command_head (case_command); #if 0 if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0))) #else if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) #endif { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } retval = run_debug_trap(); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && retval != EXECUTION_SUCCESS) { line_number = save_line_number; return (EXECUTION_SUCCESS); } #endif /* Use the same expansions (the ones POSIX specifies) as the patterns; dequote the resulting string (as POSIX specifies) since the quotes in patterns are handled specially below. We have to do it in this order because we're not supposed to perform word splitting. */ wlist = expand_word_leave_quoted (case_command->word, 0); if (wlist) { char *t; t = string_list (wlist); word = dequote_string (t); free (t); } else word = savestring (""); dispose_words (wlist); retval = EXECUTION_SUCCESS; ignore_return = case_command->flags & CMD_IGNORE_RETURN; begin_unwind_frame ("case"); add_unwind_protect (xfree, word); #define EXIT_CASE() goto exit_case_command for (clauses = case_command->clauses; clauses; clauses = clauses->next) { QUIT; for (list = clauses->patterns; list; list = list->next) { es = expand_word_leave_quoted (list->word, 0); if (es && es->word && es->word->word && *(es->word->word)) { /* Convert quoted null strings into empty strings. */ qflags = QGLOB_CVTNULL; /* We left CTLESC in place quoting CTLESC and CTLNUL after the call to expand_word_leave_quoted; tell quote_string_for_globbing to remove those here. This works for both unquoted portions of the word (which call quote_escapes) and quoted portions (which call quote_string). */ qflags |= QGLOB_CTLESC; pattern = quote_string_for_globbing (es->word->word, qflags); } else { pattern = (char *)xmalloc (1); pattern[0] = '\0'; } /* Since the pattern does not undergo quote removal (as per Posix.2, section 3.9.4.3), the strmatch () call must be able to recognize backslashes as escape characters. */ match = strmatch (pattern, word, FNMATCH_EXTFLAG|FNMATCH_IGNCASE) != FNM_NOMATCH; free (pattern); dispose_words (es); QUIT; if (match) { do { if (clauses->action && ignore_return) clauses->action->flags |= CMD_IGNORE_RETURN; retval = execute_command (clauses->action); } while ((clauses->flags & CASEPAT_FALLTHROUGH) && (clauses = clauses->next)); if (clauses == 0 || (clauses->flags & CASEPAT_TESTNEXT) == 0) EXIT_CASE (); else break; } QUIT; } } exit_case_command: free (word); discard_unwind_frame ("case"); line_number = save_line_number; return (retval); } #define CMD_WHILE 0 #define CMD_UNTIL 1 /* The WHILE command. Syntax: WHILE test DO action; DONE. Repeatedly execute action while executing test produces EXECUTION_SUCCESS. */ static int execute_while_command (while_command) WHILE_COM *while_command; { return (execute_while_or_until (while_command, CMD_WHILE)); } /* UNTIL is just like WHILE except that the test result is negated. */ static int execute_until_command (while_command) WHILE_COM *while_command; { return (execute_while_or_until (while_command, CMD_UNTIL)); } /* The body for both while and until. The only difference between the two is that the test value is treated differently. TYPE is CMD_WHILE or CMD_UNTIL. The return value for both commands should be EXECUTION_SUCCESS if no commands in the body are executed, and the status of the last command executed in the body otherwise. */ static int execute_while_or_until (while_command, type) WHILE_COM *while_command; int type; { int return_value, body_status; body_status = EXECUTION_SUCCESS; loop_level++; while_command->test->flags |= CMD_IGNORE_RETURN; if (while_command->flags & CMD_IGNORE_RETURN) while_command->action->flags |= CMD_IGNORE_RETURN; while (1) { return_value = execute_command (while_command->test); REAP (); /* Need to handle `break' in the test when we would break out of the loop. The job control code will set `breaking' to loop_level when a job in a loop is stopped with SIGTSTP. If the stopped job is in the loop test, `breaking' will not be reset unless we do this, and the shell will cease to execute commands. The same holds true for `continue'. */ if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS) { if (breaking) breaking--; if (continuing) continuing--; break; } if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS) { if (breaking) breaking--; if (continuing) continuing--; break; } QUIT; body_status = execute_command (while_command->action); QUIT; if (breaking) { breaking--; break; } if (continuing) { continuing--; if (continuing) break; } } loop_level--; return (body_status); } /* IF test THEN command [ELSE command]. IF also allows ELIF in the place of ELSE IF, but the parser makes *that* stupidity transparent. */ static int execute_if_command (if_command) IF_COM *if_command; { int return_value, save_line_number; save_line_number = line_number; if_command->test->flags |= CMD_IGNORE_RETURN; return_value = execute_command (if_command->test); line_number = save_line_number; if (return_value == EXECUTION_SUCCESS) { QUIT; if (if_command->true_case && (if_command->flags & CMD_IGNORE_RETURN)) if_command->true_case->flags |= CMD_IGNORE_RETURN; return (execute_command (if_command->true_case)); } else { QUIT; if (if_command->false_case && (if_command->flags & CMD_IGNORE_RETURN)) if_command->false_case->flags |= CMD_IGNORE_RETURN; return (execute_command (if_command->false_case)); } } #if defined (DPAREN_ARITHMETIC) static int execute_arith_command (arith_command) ARITH_COM *arith_command; { int expok, save_line_number, retval, eflag; intmax_t expresult; WORD_LIST *new; char *exp, *t; expresult = 0; save_line_number = line_number; this_command_name = "(("; /* )) */ SET_LINE_NUMBER (arith_command->line); /* If we're in a function, update the line number information. */ if (variable_context && interactive_shell && sourcelevel == 0) { /* line numbers in a function start at 1 */ line_number -= function_line_number - 1; if (line_number <= 0) line_number = 1; } command_string_index = 0; print_arith_command (arith_command->exp); if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } /* Run the debug trap before each arithmetic command, but do it after we update the line number information and before we expand the various words in the expression. */ retval = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && retval != EXECUTION_SUCCESS) { line_number = save_line_number; return (EXECUTION_SUCCESS); } #endif this_command_name = "(("; /* )) */ t = (char *)NULL; new = arith_command->exp; exp = (new->next) ? (t = string_list (new)) : new->word->word; exp = expand_arith_string (exp, Q_DOUBLE_QUOTES|Q_ARITH); FREE (t); /* If we're tracing, make a new word list with `((' at the front and `))' at the back and print it. Change xtrace_print_arith_cmd to take a string when I change eval_arith_for_expr to use expand_arith_string(). */ if (echo_command_at_execute) { new = make_word_list (make_word (exp ? exp : ""), (WORD_LIST *)NULL); xtrace_print_arith_cmd (new); dispose_words (new); } if (exp) { eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED; expresult = evalexp (exp, eflag, &expok); line_number = save_line_number; free (exp); } else { expresult = 0; expok = 1; } if (expok == 0) return (EXECUTION_FAILURE); return (expresult == 0 ? EXECUTION_FAILURE : EXECUTION_SUCCESS); } #endif /* DPAREN_ARITHMETIC */ #if defined (COND_COMMAND) static char * const nullstr = ""; /* XXX - can COND ever be NULL when this is called? */ static int execute_cond_node (cond) COND_COM *cond; { int result, invert, patmatch, rmatch, arith, mode, mflags, ignore; char *arg1, *arg2, *op; #if 0 char *t1, *t2; #endif invert = (cond->flags & CMD_INVERT_RETURN); ignore = (cond->flags & CMD_IGNORE_RETURN); if (ignore) { if (cond->left) cond->left->flags |= CMD_IGNORE_RETURN; if (cond->right) cond->right->flags |= CMD_IGNORE_RETURN; } if (cond->type == COND_EXPR) result = execute_cond_node (cond->left); else if (cond->type == COND_OR) { result = execute_cond_node (cond->left); if (result != EXECUTION_SUCCESS) result = execute_cond_node (cond->right); } else if (cond->type == COND_AND) { result = execute_cond_node (cond->left); if (result == EXECUTION_SUCCESS) result = execute_cond_node (cond->right); } else if (cond->type == COND_UNARY) { int oa, varop, varflag; if (ignore) comsub_ignore_return++; varop = STREQ (cond->op->word, "-v"); #if defined (ARRAY_VARS) varflag = (varop && valid_array_reference (cond->left->op->word, VA_NOEXPAND)) ? TEST_ARRAYEXP : 0; #else varflag = 0; #endif arg1 = cond_expand_word (cond->left->op, varop ? 3 : 0); if (ignore) comsub_ignore_return--; if (arg1 == 0) arg1 = nullstr; if (echo_command_at_execute) xtrace_print_cond_term (cond->type, invert, cond->op, arg1, (char *)NULL); #if defined (ARRAY_VARS) if (varop) oa = set_expand_once (0, 0); /* no-op for compatibility levels <= 51 */ #endif result = unary_test (cond->op->word, arg1, varflag) ? EXECUTION_SUCCESS : EXECUTION_FAILURE; #if defined (ARRAY_VARS) if (varop) assoc_expand_once = oa; #endif if (arg1 != nullstr) free (arg1); } else if (cond->type == COND_BINARY) { rmatch = 0; op = cond->op->word; mode = 0; patmatch = (((op[1] == '=') && (op[2] == '\0') && (op[0] == '!' || op[0] == '=')) || (op[0] == '=' && op[1] == '\0')); #if defined (COND_REGEXP) rmatch = (op[0] == '=' && op[1] == '~' && op[2] == '\0'); #endif arith = STREQ (op, "-eq") || STREQ (op, "-ne") || STREQ (op, "-lt") || STREQ (op, "-le") || STREQ (op, "-gt") || STREQ (op, "-ge"); if (arith) mode = 3; else if (rmatch && shell_compatibility_level > 31) mode = 2; else if (patmatch) mode = 1; if (ignore) comsub_ignore_return++; arg1 = cond_expand_word (cond->left->op, arith ? mode : 0); if (ignore) comsub_ignore_return--; if (arg1 == 0) arg1 = nullstr; if (ignore) comsub_ignore_return++; arg2 = cond_expand_word (cond->right->op, mode); if (ignore) comsub_ignore_return--; if (arg2 == 0) arg2 = nullstr; if (echo_command_at_execute) xtrace_print_cond_term (cond->type, invert, cond->op, arg1, arg2); #if defined (COND_REGEXP) if (rmatch) { mflags = SHMAT_PWARN; #if defined (ARRAY_VARS) mflags |= SHMAT_SUBEXP; #endif #if 0 t1 = strescape(arg1); t2 = strescape(arg2); itrace("execute_cond_node: sh_regmatch on `%s' and `%s'", t1, t2); free(t1); free(t2); #endif result = sh_regmatch (arg1, arg2, mflags); } else #endif /* COND_REGEXP */ { extended_glob = 1; result = binary_test (cond->op->word, arg1, arg2, TEST_PATMATCH|TEST_ARITHEXP|TEST_LOCALE) ? EXECUTION_SUCCESS : EXECUTION_FAILURE; extended_glob = extglob_flag; } if (arg1 != nullstr) free (arg1); if (arg2 != nullstr) free (arg2); } else { command_error ("execute_cond_node", CMDERR_BADTYPE, cond->type, 0); jump_to_top_level (DISCARD); result = EXECUTION_FAILURE; } if (invert) result = (result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS; return result; } static int execute_cond_command (cond_command) COND_COM *cond_command; { int retval, save_line_number; save_line_number = line_number; SET_LINE_NUMBER (cond_command->line); /* If we're in a function, update the line number information. */ if (variable_context && interactive_shell && sourcelevel == 0) { /* line numbers in a function start at 1 */ line_number -= function_line_number - 1; if (line_number <= 0) line_number = 1; } command_string_index = 0; print_cond_command (cond_command); if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) { FREE (the_printed_command_except_trap); the_printed_command_except_trap = savestring (the_printed_command); } /* Run the debug trap before each conditional command, but do it after we update the line number information. */ retval = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && retval != EXECUTION_SUCCESS) { line_number = save_line_number; return (EXECUTION_SUCCESS); } #endif this_command_name = "[["; /* ]] */ #if 0 debug_print_cond_command (cond_command); #endif last_command_exit_value = retval = execute_cond_node (cond_command); line_number = save_line_number; return (retval); } #endif /* COND_COMMAND */ static void bind_lastarg (arg) char *arg; { SHELL_VAR *var; if (arg == 0) arg = ""; var = bind_variable ("_", arg, 0); if (var) VUNSETATTR (var, att_exported); } /* Execute a null command. Fork a subshell if the command uses pipes or is to be run asynchronously. This handles all the side effects that are supposed to take place. */ static int execute_null_command (redirects, pipe_in, pipe_out, async) REDIRECT *redirects; int pipe_in, pipe_out, async; { int r; int forcefork, fork_flags; REDIRECT *rd; for (forcefork = 0, rd = redirects; rd; rd = rd->next) { forcefork += rd->rflags & REDIR_VARASSIGN; /* Safety */ forcefork += (rd->redirector.dest == 0 || fd_is_bash_input (rd->redirector.dest)) && (INPUT_REDIRECT (rd->instruction) || TRANSLATE_REDIRECT (rd->instruction) || rd->instruction == r_close_this); } if (forcefork || pipe_in != NO_PIPE || pipe_out != NO_PIPE || async) { /* We have a null command, but we really want a subshell to take care of it. Just fork, do piping and redirections, and exit. */ fork_flags = async ? FORK_ASYNC : 0; if (make_child ((char *)NULL, fork_flags) == 0) { /* Cancel traps, in trap.c. */ restore_original_signals (); /* XXX */ do_piping (pipe_in, pipe_out); #if defined (COPROCESS_SUPPORT) coproc_closeall (); #endif interactive = 0; /* XXX */ subshell_environment = 0; if (async) subshell_environment |= SUBSHELL_ASYNC; if (pipe_in != NO_PIPE || pipe_out != NO_PIPE) subshell_environment |= SUBSHELL_PIPE; if (do_redirections (redirects, RX_ACTIVE) == 0) exit (EXECUTION_SUCCESS); else exit (EXECUTION_FAILURE); } else { close_pipes (pipe_in, pipe_out); #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD) if (pipe_out == NO_PIPE) unlink_fifo_list (); #endif return (EXECUTION_SUCCESS); } } else { /* Even if there aren't any command names, pretend to do the redirections that are specified. The user expects the side effects to take place. If the redirections fail, then return failure. Otherwise, if a command substitution took place while expanding the command or a redirection, return the value of that substitution. Otherwise, return EXECUTION_SUCCESS. */ r = do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE); cleanup_redirects (redirection_undo_list); redirection_undo_list = (REDIRECT *)NULL; if (r != 0) return (EXECUTION_FAILURE); else if (last_command_subst_pid != NO_PID) return (last_command_exit_value); else return (EXECUTION_SUCCESS); } } /* This is a hack to suppress word splitting for assignment statements given as arguments to builtins with the ASSIGNMENT_BUILTIN flag set. */ static void fix_assignment_words (words) WORD_LIST *words; { WORD_LIST *w, *wcmd; struct builtin *b; int assoc, global, array, integer; if (words == 0) return; b = 0; assoc = global = array = integer = 0; /* Skip over assignment statements preceding a command name */ wcmd = words; for (wcmd = words; wcmd; wcmd = wcmd->next) if ((wcmd->word->flags & W_ASSIGNMENT) == 0) break; /* Posix (post-2008) says that `command' doesn't change whether or not the builtin it shadows is a `declaration command', even though it removes other special builtin properties. In Posix mode, we skip over one or more instances of `command' and deal with the next word as the assignment builtin. */ while (posixly_correct && wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command")) wcmd = wcmd->next; for (w = wcmd; w; w = w->next) if (w->word->flags & W_ASSIGNMENT) { /* Lazy builtin lookup, only do it if we find an assignment */ if (b == 0) { b = builtin_address_internal (wcmd->word->word, 0); if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0) return; else if (b && (b->flags & ASSIGNMENT_BUILTIN)) wcmd->word->flags |= W_ASSNBLTIN; } w->word->flags |= (W_NOSPLIT|W_NOGLOB|W_TILDEEXP|W_ASSIGNARG); #if defined (ARRAY_VARS) if (assoc) w->word->flags |= W_ASSIGNASSOC; if (array) w->word->flags |= W_ASSIGNARRAY; #endif if (global) w->word->flags |= W_ASSNGLOBAL; /* If we have an assignment builtin that does not create local variables, make sure we create global variables even if we internally call `declare'. The CHKLOCAL flag means to set attributes or values on an existing local variable, if there is one. */ if (b && ((b->flags & (ASSIGNMENT_BUILTIN|LOCALVAR_BUILTIN)) == ASSIGNMENT_BUILTIN)) w->word->flags |= W_ASSNGLOBAL|W_CHKLOCAL; else if (b && (b->flags & ASSIGNMENT_BUILTIN) && (b->flags & LOCALVAR_BUILTIN) && variable_context) w->word->flags |= W_FORCELOCAL; } #if defined (ARRAY_VARS) /* Note that we saw an associative array option to a builtin that takes assignment statements. This is a bit of a kludge. */ else if (w->word->word[0] == '-' && (strpbrk (w->word->word+1, "Aag") != 0)) #else else if (w->word->word[0] == '-' && strchr (w->word->word+1, 'g')) #endif { if (b == 0) { b = builtin_address_internal (wcmd->word->word, 0); if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0) return; else if (b && (b->flags & ASSIGNMENT_BUILTIN)) wcmd->word->flags |= W_ASSNBLTIN; } if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'A')) assoc = 1; else if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'a')) array = 1; if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'g')) global = 1; } } #if defined (ARRAY_VARS) /* Set W_ARRAYREF on words that are valid array references to a builtin that accepts them. This is intended to completely replace assoc_expand_once in time. */ static void fix_arrayref_words (words) WORD_LIST *words; { WORD_LIST *w, *wcmd; struct builtin *b; if (words == 0) return; b = 0; /* Skip over assignment statements preceding a command name */ wcmd = words; for (wcmd = words; wcmd; wcmd = wcmd->next) if ((wcmd->word->flags & W_ASSIGNMENT) == 0) break; /* Skip over `command' */ while (wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command")) wcmd = wcmd->next; if (wcmd == 0) return; /* If it's not an array reference builtin, we have nothing to do. */ b = builtin_address_internal (wcmd->word->word, 0); if (b == 0 || (b->flags & ARRAYREF_BUILTIN) == 0) return; for (w = wcmd->next; w; w = w->next) { if (w->word && w->word->word && valid_array_reference (w->word->word, 0)) w->word->flags |= W_ARRAYREF; } } #endif #ifndef ISOPTION # define ISOPTION(s, c) (s[0] == '-' && s[1] == c && s[2] == 0) #endif #define RETURN_NOT_COMMAND() \ do { if (typep) *typep = 0; return words; } while (0) /* Make sure we have `command [-p] command_name [args]', and handle skipping over the usual `--' that ends the options. Returns the updated WORDS with the command and options stripped and sets *TYPEP to a non-zero value. If any other options are supplied, or there is not a command_name, we punt and return a zero value in *TYPEP without updating WORDS. */ static WORD_LIST * check_command_builtin (words, typep) WORD_LIST *words; int *typep; { int type; WORD_LIST *w; w = words->next; type = 1; if (w && ISOPTION (w->word->word, 'p')) /* command -p */ { #if defined (RESTRICTED_SHELL) if (restricted) RETURN_NOT_COMMAND(); #endif w = w->next; type = 2; } if (w && ISOPTION (w->word->word, '-')) /* command [-p] -- */ w = w->next; else if (w && w->word->word[0] == '-') /* any other option */ RETURN_NOT_COMMAND(); if (w == 0 || w->word->word == 0) /* must have a command_name */ RETURN_NOT_COMMAND(); if (typep) *typep = type; return w; } /* Return 1 if the file found by searching $PATH for PATHNAME, defaulting to PATHNAME, is a directory. Used by the autocd code below. */ static int is_dirname (pathname) char *pathname; { char *temp; int ret; temp = search_for_command (pathname, 0); ret = temp ? file_isdir (temp) : file_isdir (pathname); free (temp); return ret; } /* The meaty part of all the executions. We have to start hacking the real execution of commands here. Fork a process, set things up, execute the command. */ static int execute_simple_command (simple_command, pipe_in, pipe_out, async, fds_to_close) SIMPLE_COM *simple_command; int pipe_in, pipe_out, async; struct fd_bitmap *fds_to_close; { WORD_LIST *words, *lastword; char *command_line, *lastarg, *temp; int first_word_quoted, result, builtin_is_special, already_forked, dofork; int fork_flags, cmdflags; pid_t old_last_async_pid; sh_builtin_func_t *builtin; SHELL_VAR *func; volatile int old_builtin, old_command_builtin; result = EXECUTION_SUCCESS; special_builtin_failed = builtin_is_special = 0; command_line = (char *)0; QUIT; /* If we're in a function, update the line number information. */ if (variable_context && interactive_shell && sourcelevel == 0) { /* line numbers in a function start at 1 */ line_number -= function_line_number - 1; if (line_number <= 0) line_number = 1; } /* Remember what this command line looks like at invocation. */ command_string_index = 0; print_simple_command (simple_command); #if 0 if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0))) #else if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0) #endif { FREE (the_printed_command_except_trap); the_printed_command_except_trap = the_printed_command ? savestring (the_printed_command) : (char *)0; } /* Run the debug trap before each simple command, but do it after we update the line number information. */ result = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode && result != EXECUTION_SUCCESS) return (EXECUTION_SUCCESS); #endif cmdflags = simple_command->flags; first_word_quoted = simple_command->words ? (simple_command->words->word->flags & W_QUOTED) : 0; last_command_subst_pid = NO_PID; old_last_async_pid = last_asynchronous_pid; already_forked = 0; /* If we're in a pipeline or run in the background, set DOFORK so we make the child early, before word expansion. This keeps assignment statements from affecting the parent shell's environment when they should not. */ dofork = pipe_in != NO_PIPE || pipe_out != NO_PIPE || async; /* Something like `%2 &' should restart job 2 in the background, not cause the shell to fork here. */ if (dofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE && simple_command->words && simple_command->words->word && simple_command->words->word->word && (simple_command->words->word->word[0] == '%')) dofork = 0; if (dofork) { char *p; /* Do this now, because execute_disk_command will do it anyway in the vast majority of cases. */ maybe_make_export_env (); /* Don't let a DEBUG trap overwrite the command string to be saved with the process/job associated with this child. */ fork_flags = async ? FORK_ASYNC : 0; if (make_child (p = savestring (the_printed_command_except_trap), fork_flags) == 0) { already_forked = 1; cmdflags |= CMD_NO_FORK; /* We redo some of what make_child() does with SUBSHELL_IGNTRAP */ subshell_environment = SUBSHELL_FORK|SUBSHELL_IGNTRAP; /* XXX */ if (pipe_in != NO_PIPE || pipe_out != NO_PIPE) subshell_environment |= SUBSHELL_PIPE; if (async) subshell_environment |= SUBSHELL_ASYNC; /* We need to do this before piping to handle some really pathological cases where one of the pipe file descriptors is < 2. */ if (fds_to_close) close_fd_bitmap (fds_to_close); /* If we fork because of an input pipe, note input pipe for later to inhibit async commands from redirecting stdin from /dev/null */ stdin_redir |= pipe_in != NO_PIPE; do_piping (pipe_in, pipe_out); pipe_in = pipe_out = NO_PIPE; #if defined (COPROCESS_SUPPORT) coproc_closeall (); #endif last_asynchronous_pid = old_last_async_pid; if (async) subshell_level++; /* not for pipes yet */ #if defined (JOB_CONTROL) FREE (p); /* child doesn't use pointer */ #endif } else { /* Don't let simple commands that aren't the last command in a pipeline change $? for the rest of the pipeline (or at all). */ if (pipe_out != NO_PIPE) result = last_command_exit_value; close_pipes (pipe_in, pipe_out); command_line = (char *)NULL; /* don't free this. */ return (result); } } QUIT; /* XXX */ /* If we are re-running this as the result of executing the `command' builtin, do not expand the command words a second time. */ if ((cmdflags & CMD_INHIBIT_EXPANSION) == 0) { current_fds_to_close = fds_to_close; fix_assignment_words (simple_command->words); #if defined (ARRAY_VARS) fix_arrayref_words (simple_command->words); #endif /* Pass the ignore return flag down to command substitutions */ if (cmdflags & CMD_IGNORE_RETURN) /* XXX */ comsub_ignore_return++; words = expand_words (simple_command->words); if (cmdflags & CMD_IGNORE_RETURN) comsub_ignore_return--; current_fds_to_close = (struct fd_bitmap *)NULL; } else words = copy_word_list (simple_command->words); /* It is possible for WORDS not to have anything left in it. Perhaps all the words consisted of `$foo', and there was no variable `$foo'. */ if (words == 0) { this_command_name = 0; result = execute_null_command (simple_command->redirects, pipe_in, pipe_out, already_forked ? 0 : async); if (already_forked) sh_exit (result); else { bind_lastarg ((char *)NULL); set_pipestatus_from_exit (result); return (result); } } lastarg = (char *)NULL; begin_unwind_frame ("simple-command"); if (echo_command_at_execute && (cmdflags & CMD_COMMAND_BUILTIN) == 0) xtrace_print_word_list (words, 1); builtin = (sh_builtin_func_t *)NULL; func = (SHELL_VAR *)NULL; /* This test is still here in case we want to change the command builtin handler code below to recursively call execute_simple_command (after modifying the simple_command struct). */ if ((cmdflags & CMD_NO_FUNCTIONS) == 0) { /* Posix.2 says special builtins are found before functions. We don't set builtin_is_special anywhere other than here, because this path is followed only when the `command' builtin is *not* being used, and we don't want to exit the shell if a special builtin executed with `command builtin' fails. `command' is not a special builtin. */ if (posixly_correct) { builtin = find_special_builtin (words->word->word); if (builtin) builtin_is_special = 1; } if (builtin == 0) func = find_function (words->word->word); } /* What happens in posix mode when an assignment preceding a command name fails. This should agree with the code in execute_cmd.c: do_assignment_statements(), even though I don't think it's executed any more. */ if (posixly_correct && tempenv_assign_error) { #if defined (DEBUG) /* I don't know if this clause is ever executed, so let's check */ itrace("execute_simple_command: posix mode tempenv assignment error"); #endif last_command_exit_value = EXECUTION_FAILURE; #if defined (STRICT_POSIX) jump_to_top_level ((interactive_shell == 0) ? FORCE_EOF : DISCARD); #else if (interactive_shell == 0 && builtin_is_special) jump_to_top_level (FORCE_EOF); else if (interactive_shell == 0) jump_to_top_level (DISCARD); /* XXX - maybe change later */ else jump_to_top_level (DISCARD); #endif } tempenv_assign_error = 0; /* don't care about this any more */ /* This is where we handle the command builtin as a pseudo-reserved word prefix. This allows us to optimize away forks if we can. */ old_command_builtin = -1; if (builtin == 0 && func == 0) { WORD_LIST *disposer, *l; int cmdtype; builtin = find_shell_builtin (words->word->word); while (builtin == command_builtin) { disposer = words; cmdtype = 0; words = check_command_builtin (words, &cmdtype); if (cmdtype > 0) /* command -p [--] words */ { for (l = disposer; l->next != words; l = l->next) ; l->next = 0; dispose_words (disposer); cmdflags |= CMD_COMMAND_BUILTIN | CMD_NO_FUNCTIONS; if (cmdtype == 2) cmdflags |= CMD_STDPATH; builtin = find_shell_builtin (words->word->word); } else break; } if (cmdflags & CMD_COMMAND_BUILTIN) { old_command_builtin = executing_command_builtin; unwind_protect_int (executing_command_builtin); executing_command_builtin |= 1; } builtin = 0; } add_unwind_protect (dispose_words, words); QUIT; /* Bind the last word in this command to "$_" after execution. */ for (lastword = words; lastword->next; lastword = lastword->next) ; lastarg = lastword->word->word; #if defined (JOB_CONTROL) /* Is this command a job control related thing? */ if (words->word->word[0] == '%' && already_forked == 0) { this_command_name = async ? "bg" : "fg"; last_shell_builtin = this_shell_builtin; this_shell_builtin = builtin_address (this_command_name); result = (*this_shell_builtin) (words); goto return_result; } /* One other possibililty. The user may want to resume an existing job. If they do, find out whether this word is a candidate for a running job. */ if (job_control && already_forked == 0 && async == 0 && !first_word_quoted && !words->next && words->word->word[0] && !simple_command->redirects && pipe_in == NO_PIPE && pipe_out == NO_PIPE && (temp = get_string_value ("auto_resume"))) { int job, jflags, started_status; jflags = JM_STOPPED|JM_FIRSTMATCH; if (STREQ (temp, "exact")) jflags |= JM_EXACT; else if (STREQ (temp, "substring")) jflags |= JM_SUBSTRING; else jflags |= JM_PREFIX; job = get_job_by_name (words->word->word, jflags); if (job != NO_JOB) { run_unwind_frame ("simple-command"); this_command_name = "fg"; last_shell_builtin = this_shell_builtin; this_shell_builtin = builtin_address ("fg"); started_status = start_job (job, 1); return ((started_status < 0) ? EXECUTION_FAILURE : started_status); } } #endif /* JOB_CONTROL */ run_builtin: /* Remember the name of this command globally. */ this_command_name = words->word->word; QUIT; /* This command could be a shell builtin or a user-defined function. We have already found special builtins by this time, so we do not set builtin_is_special. If this is a function or builtin, and we have pipes, then fork a subshell in here. Otherwise, just execute the command directly. */ if (func == 0 && builtin == 0) builtin = find_shell_builtin (this_command_name); last_shell_builtin = this_shell_builtin; this_shell_builtin = builtin; if (builtin || func) { if (builtin) { old_builtin = executing_builtin; unwind_protect_int (executing_builtin); /* modified in execute_builtin */ if (old_command_builtin == -1) /* sentinel, can be set above */ { old_command_builtin = executing_command_builtin; unwind_protect_int (executing_command_builtin); /* ditto and set above */ } } if (already_forked) { /* reset_terminating_signals (); */ /* XXX */ /* Reset the signal handlers in the child, but don't free the trap strings. Set a flag noting that we have to free the trap strings if we run trap to change a signal disposition. */ reset_signal_handlers (); subshell_environment |= SUBSHELL_RESETTRAP; subshell_environment &= ~SUBSHELL_IGNTRAP; if (async) { if ((cmdflags & CMD_STDIN_REDIR) && pipe_in == NO_PIPE && (stdin_redirects (simple_command->redirects) == 0)) async_redirect_stdin (); setup_async_signals (); } if (async == 0) subshell_level++; execute_subshell_builtin_or_function (words, simple_command->redirects, builtin, func, pipe_in, pipe_out, async, fds_to_close, cmdflags); subshell_level--; } else { result = execute_builtin_or_function (words, builtin, func, simple_command->redirects, fds_to_close, cmdflags); if (builtin) { if (result > EX_SHERRBASE) { switch (result) { case EX_REDIRFAIL: case EX_BADASSIGN: case EX_EXPFAIL: /* These errors cause non-interactive posix mode shells to exit */ if (posixly_correct && builtin_is_special && interactive_shell == 0) { last_command_exit_value = EXECUTION_FAILURE; jump_to_top_level (ERREXIT); } break; case EX_DISKFALLBACK: /* XXX - experimental */ executing_builtin = old_builtin; executing_command_builtin = old_command_builtin; builtin = 0; /* The redirections have already been `undone', so this will have to do them again. But piping is forever. */ pipe_in = pipe_out = -1; goto execute_from_filesystem; } result = builtin_status (result); if (builtin_is_special) special_builtin_failed = 1; /* XXX - take command builtin into account? */ } /* In POSIX mode, if there are assignment statements preceding a special builtin, they persist after the builtin completes. */ if (posixly_correct && builtin_is_special && temporary_env) merge_temporary_env (); } else /* function */ { if (result == EX_USAGE) result = EX_BADUSAGE; else if (result > EX_SHERRBASE) result = builtin_status (result); } set_pipestatus_from_exit (result); goto return_result; } } if (autocd && interactive && words->word && is_dirname (words->word->word)) { words = make_word_list (make_word ("--"), words); words = make_word_list (make_word ("cd"), words); xtrace_print_word_list (words, 0); func = find_function ("cd"); goto run_builtin; } execute_from_filesystem: if (command_line == 0) command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : ""); #if defined (PROCESS_SUBSTITUTION) /* The old code did not test already_forked and only did this if subshell_environment&SUBSHELL_COMSUB != 0 (comsubs and procsubs). Other uses of the no-fork optimization left FIFOs in $TMPDIR */ if (already_forked == 0 && (cmdflags & CMD_NO_FORK) && fifos_pending() > 0) cmdflags &= ~CMD_NO_FORK; #endif result = execute_disk_command (words, simple_command->redirects, command_line, pipe_in, pipe_out, async, fds_to_close, cmdflags); return_result: bind_lastarg (lastarg); FREE (command_line); dispose_words (words); if (builtin) { executing_builtin = old_builtin; executing_command_builtin = old_command_builtin; } discard_unwind_frame ("simple-command"); this_command_name = (char *)NULL; /* points to freed memory now */ return (result); } /* Translate the special builtin exit statuses. We don't really need a function for this; it's a placeholder for future work. */ static int builtin_status (result) int result; { int r; switch (result) { case EX_USAGE: case EX_BADSYNTAX: r = EX_BADUSAGE; break; case EX_REDIRFAIL: case EX_BADASSIGN: case EX_EXPFAIL: r = EXECUTION_FAILURE; break; default: /* other special exit statuses not yet defined */ r = (result > EX_SHERRBASE) ? EXECUTION_FAILURE : EXECUTION_SUCCESS; break; } return (r); } static int execute_builtin (builtin, words, flags, subshell) sh_builtin_func_t *builtin; WORD_LIST *words; int flags, subshell; { int result, eval_unwind, ignexit_flag; int isbltinenv, should_keep; char *error_trap; error_trap = 0; should_keep = 0; /* The eval builtin calls parse_and_execute, which does not know about the setting of flags, and always calls the execution functions with flags that will exit the shell on an error if -e is set. If the eval builtin is being called, and we're supposed to ignore the exit value of the command, we turn the -e flag off ourselves and disable the ERR trap, then restore them when the command completes. This is also a problem (as below) for the command and source/. builtins. */ if (subshell == 0 && (flags & CMD_IGNORE_RETURN) && (builtin == eval_builtin || (flags & CMD_COMMAND_BUILTIN) || builtin == source_builtin)) { begin_unwind_frame ("eval_builtin"); unwind_protect_int (exit_immediately_on_error); unwind_protect_int (builtin_ignoring_errexit); error_trap = TRAP_STRING (ERROR_TRAP); if (error_trap) { error_trap = savestring (error_trap); add_unwind_protect (xfree, error_trap); add_unwind_protect (set_error_trap, error_trap); restore_default_signal (ERROR_TRAP); } exit_immediately_on_error = 0; ignexit_flag = builtin_ignoring_errexit; builtin_ignoring_errexit = 1; eval_unwind = 1; } else eval_unwind = 0; /* The temporary environment for a builtin is supposed to apply to all commands executed by that builtin. Currently, this is a problem only with the `unset', `source' and `eval' builtins. `mapfile' is a special case because it uses evalstring (same as eval or source) to run its callbacks. */ /* SHOULD_KEEP is for the pop_scope call below; it only matters when posixly_correct is set, but we should propagate the temporary environment to the enclosing environment only for special builtins. */ isbltinenv = (builtin == source_builtin || builtin == eval_builtin || builtin == unset_builtin || builtin == mapfile_builtin); should_keep = isbltinenv && builtin != mapfile_builtin; #if defined (HISTORY) && defined (READLINE) if (builtin == fc_builtin || builtin == read_builtin) { isbltinenv = 1; should_keep = 0; } #endif if (isbltinenv) { if (subshell == 0) begin_unwind_frame ("builtin_env"); if (temporary_env) { push_scope (VC_BLTNENV, temporary_env); if (flags & CMD_COMMAND_BUILTIN) should_keep = 0; if (subshell == 0) add_unwind_protect (pop_scope, should_keep ? "1" : 0); temporary_env = (HASH_TABLE *)NULL; } } if (subshell == 0 && builtin == eval_builtin) { if (evalnest_max > 0 && evalnest >= evalnest_max) { internal_error (_("eval: maximum eval nesting level exceeded (%d)"), evalnest); evalnest = 0; jump_to_top_level (DISCARD); } unwind_protect_int (evalnest); /* The test for subshell == 0 above doesn't make a difference */ evalnest++; /* execute_subshell_builtin_or_function sets this to 0 */ } else if (subshell == 0 && builtin == source_builtin) { if (sourcenest_max > 0 && sourcenest >= sourcenest_max) { internal_error (_("%s: maximum source nesting level exceeded (%d)"), this_command_name, sourcenest); sourcenest = 0; jump_to_top_level (DISCARD); } unwind_protect_int (sourcenest); /* The test for subshell == 0 above doesn't make a difference */ sourcenest++; /* execute_subshell_builtin_or_function sets this to 0 */ } /* `return' does a longjmp() back to a saved environment in execute_function. If a variable assignment list preceded the command, and the shell is running in POSIX mode, we need to merge that into the shell_variables table, since `return' is a POSIX special builtin. We don't do this if it's being run by the `command' builtin, since that's supposed to inhibit the special builtin properties. */ if (posixly_correct && subshell == 0 && builtin == return_builtin && (flags & CMD_COMMAND_BUILTIN) == 0 && temporary_env) { begin_unwind_frame ("return_temp_env"); add_unwind_protect (merge_temporary_env, (char *)NULL); } executing_builtin++; executing_command_builtin |= builtin == command_builtin; result = ((*builtin) (words->next)); /* This shouldn't happen, but in case `return' comes back instead of longjmp'ing, we need to unwind. */ if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env) discard_unwind_frame ("return_temp_env"); if (subshell == 0 && isbltinenv) run_unwind_frame ("builtin_env"); if (eval_unwind) { builtin_ignoring_errexit = ignexit_flag; exit_immediately_on_error = builtin_ignoring_errexit ? 0 : errexit_flag; if (error_trap) { set_error_trap (error_trap); free (error_trap); } discard_unwind_frame ("eval_builtin"); } return (result); } static void maybe_restore_getopt_state (gs) sh_getopt_state_t *gs; { /* If we have a local copy of OPTIND and it's at the right (current) context, then we restore getopt's internal state. If not, we just let it go. We know there is a local OPTIND if gs->gs_flags & 1. This is set below in execute_function() before the context is run. */ if (gs->gs_flags & 1) sh_getopt_restore_istate (gs); else free (gs); } #if defined (ARRAY_VARS) void restore_funcarray_state (fa) struct func_array_state *fa; { SHELL_VAR *nfv; ARRAY *funcname_a; array_pop (fa->source_a); array_pop (fa->lineno_a); GET_ARRAY_FROM_VAR ("FUNCNAME", nfv, funcname_a); if (nfv == fa->funcname_v) array_pop (funcname_a); free (fa); } #endif static int execute_function (var, words, flags, fds_to_close, async, subshell) SHELL_VAR *var; WORD_LIST *words; int flags; struct fd_bitmap *fds_to_close; int async, subshell; { int return_val, result, lineno; COMMAND *tc, *fc, *save_current; char *debug_trap, *error_trap, *return_trap; #if defined (ARRAY_VARS) SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v; ARRAY *funcname_a; volatile ARRAY *bash_source_a; volatile ARRAY *bash_lineno_a; struct func_array_state *fa; #endif FUNCTION_DEF *shell_fn; char *sfile, *t; sh_getopt_state_t *gs; SHELL_VAR *gv; USE_VAR(fc); if (funcnest_max > 0 && funcnest >= funcnest_max) { internal_error (_("%s: maximum function nesting level exceeded (%d)"), var->name, funcnest); funcnest = 0; /* XXX - should we reset it somewhere else? */ jump_to_top_level (DISCARD); } #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); #endif tc = (COMMAND *)copy_command (function_cell (var)); if (tc && (flags & CMD_IGNORE_RETURN)) tc->flags |= CMD_IGNORE_RETURN; /* A limited attempt at optimization: shell functions at the end of command substitutions that are already marked NO_FORK. */ if (tc && (flags & CMD_NO_FORK) && (subshell_environment & SUBSHELL_COMSUB)) optimize_shell_function (tc); gs = sh_getopt_save_istate (); if (subshell == 0) { begin_unwind_frame ("function_calling"); /* If the shell is in posix mode, this will push the variables in the temporary environment to the "current shell environment" (the global scope), and dispose the temporary env before setting it to NULL later. This behavior has disappeared from the latest edition of the standard, so I will eventually remove it from variables.c: push_var_context. */ push_context (var->name, subshell, temporary_env); /* This has to be before the pop_context(), because the unwinding of local variables may cause the restore of a local declaration of OPTIND to force a getopts state reset. */ add_unwind_protect (maybe_restore_getopt_state, gs); add_unwind_protect (pop_context, (char *)NULL); unwind_protect_int (line_number); unwind_protect_int (line_number_for_err_trap); unwind_protect_int (function_line_number); unwind_protect_int (return_catch_flag); unwind_protect_jmp_buf (return_catch); add_unwind_protect (dispose_command, (char *)tc); unwind_protect_pointer (this_shell_function); unwind_protect_int (funcnest); unwind_protect_int (loop_level); } else push_context (var->name, subshell, temporary_env); /* don't unwind-protect for subshells */ temporary_env = (HASH_TABLE *)NULL; this_shell_function = var; make_funcname_visible (1); debug_trap = TRAP_STRING(DEBUG_TRAP); error_trap = TRAP_STRING(ERROR_TRAP); return_trap = TRAP_STRING(RETURN_TRAP); /* The order of the unwind protects for debug_trap, error_trap and return_trap is important here! unwind-protect commands are run in reverse order of registration. If this causes problems, take out the xfree unwind-protect calls and live with the small memory leak. */ /* function_trace_mode != 0 means that all functions inherit the DEBUG trap. if the function has the trace attribute set, it inherits the DEBUG trap */ if (debug_trap && ((trace_p (var) == 0) && function_trace_mode == 0)) { if (subshell == 0) { debug_trap = savestring (debug_trap); add_unwind_protect (xfree, debug_trap); add_unwind_protect (maybe_set_debug_trap, debug_trap); } restore_default_signal (DEBUG_TRAP); } /* error_trace_mode != 0 means that functions inherit the ERR trap. */ if (error_trap && error_trace_mode == 0) { if (subshell == 0) { error_trap = savestring (error_trap); add_unwind_protect (xfree, error_trap); add_unwind_protect (maybe_set_error_trap, error_trap); } restore_default_signal (ERROR_TRAP); } /* Shell functions inherit the RETURN trap if function tracing is on globally or on individually for this function. */ if (return_trap && (signal_in_progress (DEBUG_TRAP) || ((trace_p (var) == 0) && function_trace_mode == 0))) { if (subshell == 0) { return_trap = savestring (return_trap); add_unwind_protect (xfree, return_trap); add_unwind_protect (maybe_set_return_trap, return_trap); } restore_default_signal (RETURN_TRAP); } funcnest++; #if defined (ARRAY_VARS) /* This is quite similar to the code in shell.c and elsewhere. */ shell_fn = find_function_def (this_shell_function->name); sfile = shell_fn ? shell_fn->source_file : ""; array_push ((ARRAY *)funcname_a, this_shell_function->name); array_push ((ARRAY *)bash_source_a, sfile); lineno = GET_LINE_NUMBER (); t = itos (lineno); array_push ((ARRAY *)bash_lineno_a, t); free (t); #endif #if defined (ARRAY_VARS) fa = (struct func_array_state *)xmalloc (sizeof (struct func_array_state)); fa->source_a = (ARRAY *)bash_source_a; fa->source_v = bash_source_v; fa->lineno_a = (ARRAY *)bash_lineno_a; fa->lineno_v = bash_lineno_v; fa->funcname_a = (ARRAY *)funcname_a; fa->funcname_v = funcname_v; if (subshell == 0) add_unwind_protect (restore_funcarray_state, fa); #endif /* The temporary environment for a function is supposed to apply to all commands executed within the function body. */ /* Initialize BASH_ARGC and BASH_ARGV before we blow away the positional parameters */ if (debugging_mode || shell_compatibility_level <= 44) init_bash_argv (); remember_args (words->next, 1); /* Update BASH_ARGV and BASH_ARGC */ if (debugging_mode) { push_args (words->next); if (subshell == 0) add_unwind_protect (pop_args, 0); } /* Number of the line on which the function body starts. */ line_number = function_line_number = tc->line; #if defined (JOB_CONTROL) if (subshell) stop_pipeline (async, (COMMAND *)NULL); #endif if (shell_compatibility_level > 43) loop_level = 0; fc = tc; from_return_trap = 0; return_catch_flag++; return_val = setjmp_nosigs (return_catch); if (return_val) { result = return_catch_value; /* Run the RETURN trap in the function's context. */ save_current = currently_executing_command; if (from_return_trap == 0) run_return_trap (); currently_executing_command = save_current; } else { /* Run the debug trap here so we can trap at the start of a function's execution rather than the execution of the body's first command. */ showing_function_line = 1; save_current = currently_executing_command; result = run_debug_trap (); #if defined (DEBUGGER) /* In debugging mode, if the DEBUG trap returns a non-zero status, we skip the command. */ if (debugging_mode == 0 || result == EXECUTION_SUCCESS) { showing_function_line = 0; currently_executing_command = save_current; result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close); /* Run the RETURN trap in the function's context */ save_current = currently_executing_command; run_return_trap (); currently_executing_command = save_current; } #else result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close); save_current = currently_executing_command; run_return_trap (); currently_executing_command = save_current; #endif showing_function_line = 0; } /* If we have a local copy of OPTIND, note it in the saved getopts state. */ gv = find_variable ("OPTIND"); if (gv && gv->context == variable_context) gs->gs_flags |= 1; if (subshell == 0) run_unwind_frame ("function_calling"); #if defined (ARRAY_VARS) else { restore_funcarray_state (fa); /* Restore BASH_ARGC and BASH_ARGV */ if (debugging_mode) pop_args (); } #endif if (variable_context == 0 || this_shell_function == 0) { make_funcname_visible (0); #if defined (PROCESS_SUBSTITUTION) unlink_fifo_list (); #endif } return (result); } /* A convenience routine for use by other parts of the shell to execute a particular shell function. */ int execute_shell_function (var, words) SHELL_VAR *var; WORD_LIST *words; { int ret; struct fd_bitmap *bitmap; bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE); begin_unwind_frame ("execute-shell-function"); add_unwind_protect (dispose_fd_bitmap, (char *)bitmap); ret = execute_function (var, words, 0, bitmap, 0, 0); dispose_fd_bitmap (bitmap); discard_unwind_frame ("execute-shell-function"); return ret; } /* Execute a shell builtin or function in a subshell environment. This routine does not return; it only calls exit(). If BUILTIN is non-null, it points to a function to call to execute a shell builtin; otherwise VAR points at the body of a function to execute. WORDS is the arguments to the command, REDIRECTS specifies redirections to perform before the command is executed. */ static void execute_subshell_builtin_or_function (words, redirects, builtin, var, pipe_in, pipe_out, async, fds_to_close, flags) WORD_LIST *words; REDIRECT *redirects; sh_builtin_func_t *builtin; SHELL_VAR *var; int pipe_in, pipe_out, async; struct fd_bitmap *fds_to_close; int flags; { int result, r, funcvalue; #if defined (JOB_CONTROL) int jobs_hack; jobs_hack = (builtin == jobs_builtin) && ((subshell_environment & SUBSHELL_ASYNC) == 0 || pipe_out != NO_PIPE); #endif /* A subshell is neither a login shell nor interactive. */ login_shell = interactive = 0; if (builtin == eval_builtin) evalnest = 0; else if (builtin == source_builtin) sourcenest = 0; if (async) subshell_environment |= SUBSHELL_ASYNC; if (pipe_in != NO_PIPE || pipe_out != NO_PIPE) subshell_environment |= SUBSHELL_PIPE; maybe_make_export_env (); /* XXX - is this needed? */ #if defined (JOB_CONTROL) /* Eradicate all traces of job control after we fork the subshell, so all jobs begun by this subshell are in the same process group as the shell itself. */ /* Allow the output of `jobs' to be piped. */ if (jobs_hack) kill_current_pipeline (); else without_job_control (); set_sigchld_handler (); #else without_job_control (); #endif /* JOB_CONTROL */ set_sigint_handler (); if (fds_to_close) close_fd_bitmap (fds_to_close); do_piping (pipe_in, pipe_out); if (do_redirections (redirects, RX_ACTIVE) != 0) exit (EXECUTION_FAILURE); if (builtin) { /* Give builtins a place to jump back to on failure, so we don't go back up to main(). */ result = setjmp_nosigs (top_level); /* Give the return builtin a place to jump to when executed in a subshell or pipeline */ funcvalue = 0; if (return_catch_flag && builtin == return_builtin) funcvalue = setjmp_nosigs (return_catch); if (result == EXITPROG || result == EXITBLTIN) subshell_exit (last_command_exit_value); else if (result) subshell_exit (EXECUTION_FAILURE); else if (funcvalue) subshell_exit (return_catch_value); else { r = execute_builtin (builtin, words, flags, 1); fflush (stdout); if (r == EX_USAGE) r = EX_BADUSAGE; /* XXX - experimental */ else if (r == EX_DISKFALLBACK) { char *command_line; command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : ""); r = execute_disk_command (words, (REDIRECT *)0, command_line, -1, -1, async, (struct fd_bitmap *)0, flags|CMD_NO_FORK); } subshell_exit (r); } } else { r = execute_function (var, words, flags, fds_to_close, async, 1); fflush (stdout); subshell_exit (r); } } /* Execute a builtin or function in the current shell context. If BUILTIN is non-null, it is the builtin command to execute, otherwise VAR points to the body of a function. WORDS are the command's arguments, REDIRECTS are the redirections to perform. FDS_TO_CLOSE is the usual bitmap of file descriptors to close. If BUILTIN is exec_builtin, the redirections specified in REDIRECTS are not undone before this function returns. */ static int execute_builtin_or_function (words, builtin, var, redirects, fds_to_close, flags) WORD_LIST *words; sh_builtin_func_t *builtin; SHELL_VAR *var; REDIRECT *redirects; struct fd_bitmap *fds_to_close; int flags; { int result; REDIRECT *saved_undo_list; #if defined (PROCESS_SUBSTITUTION) int ofifo, nfifo, osize; void *ofifo_list; #endif #if defined (PROCESS_SUBSTITUTION) begin_unwind_frame ("saved_fifos"); /* If we return, we longjmp and don't get a chance to restore the old fifo list, so we add an unwind protect to free it */ ofifo = num_fifos (); ofifo_list = copy_fifo_list (&osize); if (ofifo_list) add_unwind_protect (xfree, ofifo_list); #endif if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0) { undo_partial_redirects (); dispose_exec_redirects (); #if defined (PROCESS_SUBSTITUTION) free (ofifo_list); #endif return (EX_REDIRFAIL); /* was EXECUTION_FAILURE */ } saved_undo_list = redirection_undo_list; /* Calling the "exec" builtin changes redirections forever. */ if (builtin == exec_builtin) { dispose_redirects (saved_undo_list); saved_undo_list = exec_redirection_undo_list; exec_redirection_undo_list = (REDIRECT *)NULL; } else dispose_exec_redirects (); if (saved_undo_list) { begin_unwind_frame ("saved-redirects"); add_unwind_protect (cleanup_redirects, (char *)saved_undo_list); } redirection_undo_list = (REDIRECT *)NULL; if (builtin) result = execute_builtin (builtin, words, flags, 0); else result = execute_function (var, words, flags, fds_to_close, 0, 0); /* We do this before undoing the effects of any redirections. */ fflush (stdout); fpurge (stdout); if (ferror (stdout)) clearerr (stdout); /* If we are executing the `command' builtin, but this_shell_builtin is set to `exec_builtin', we know that we have something like `command exec [redirection]', since otherwise `exec' would have overwritten the shell and we wouldn't get here. In this case, we want to behave as if the `command' builtin had not been specified and preserve the redirections. */ if (builtin == command_builtin && this_shell_builtin == exec_builtin) { int discard; discard = 0; if (saved_undo_list) { dispose_redirects (saved_undo_list); discard = 1; } redirection_undo_list = exec_redirection_undo_list; saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL; if (discard) discard_unwind_frame ("saved-redirects"); } if (saved_undo_list) { redirection_undo_list = saved_undo_list; discard_unwind_frame ("saved-redirects"); } undo_partial_redirects (); #if defined (PROCESS_SUBSTITUTION) /* Close any FIFOs created by this builtin or function. */ nfifo = num_fifos (); if (nfifo > ofifo) close_new_fifos (ofifo_list, osize); if (ofifo_list) free (ofifo_list); discard_unwind_frame ("saved_fifos"); #endif return (result); } void setup_async_signals () { #if defined (__BEOS__) set_signal_handler (SIGHUP, SIG_IGN); /* they want csh-like behavior */ #endif #if defined (JOB_CONTROL) if (job_control == 0) #endif { /* Make sure we get the original signal dispositions now so we don't confuse the trap builtin later if the subshell tries to use it to reset SIGINT/SIGQUIT. Don't call set_signal_ignored; that sets the value of original_signals to SIG_IGN. Posix interpretation 751. */ get_original_signal (SIGINT); set_signal_handler (SIGINT, SIG_IGN); get_original_signal (SIGQUIT); set_signal_handler (SIGQUIT, SIG_IGN); } } /* Execute a simple command that is hopefully defined in a disk file somewhere. 1) fork () 2) connect pipes 3) look up the command 4) do redirections 5) execve () 6) If the execve failed, see if the file has executable mode set. If so, and it isn't a directory, then execute its contents as a shell script. Note that the filename hashing stuff has to take place up here, in the parent. This is probably why the Bourne style shells don't handle it, since that would require them to go through this gnarly hair, for no good reason. NOTE: callers expect this to fork or exit(). */ /* Name of a shell function to call when a command name is not found. */ #ifndef NOTFOUND_HOOK # define NOTFOUND_HOOK "command_not_found_handle" #endif static int execute_disk_command (words, redirects, command_line, pipe_in, pipe_out, async, fds_to_close, cmdflags) WORD_LIST *words; REDIRECT *redirects; char *command_line; int pipe_in, pipe_out, async; struct fd_bitmap *fds_to_close; int cmdflags; { char *pathname, *command, **args, *p; int nofork, stdpath, result, fork_flags; pid_t pid; SHELL_VAR *hookf; WORD_LIST *wl; stdpath = (cmdflags & CMD_STDPATH); /* use command -p path */ nofork = (cmdflags & CMD_NO_FORK); /* Don't fork, just exec, if no pipes */ pathname = words->word->word; p = 0; result = EXECUTION_SUCCESS; #if defined (RESTRICTED_SHELL) command = (char *)NULL; if (restricted && mbschr (pathname, '/')) { internal_error (_("%s: restricted: cannot specify `/' in command names"), pathname); result = last_command_exit_value = EXECUTION_FAILURE; /* If we're not going to fork below, we must already be in a child process or a context in which it's safe to call exit(2). */ if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE) exit (last_command_exit_value); else goto parent_return; } #endif /* RESTRICTED_SHELL */ /* If we want to change this so `command -p' (CMD_STDPATH) does not insert any pathname it finds into the hash table, it should read command = search_for_command (pathname, stdpath ? CMDSRCH_STDPATH : CMDSRCH_HASH); */ command = search_for_command (pathname, CMDSRCH_HASH|(stdpath ? CMDSRCH_STDPATH : 0)); QUIT; if (command) { /* If we're optimizing out the fork (implicit `exec'), decrement the shell level like `exec' would do. Don't do this if we are already in a pipeline environment, assuming it's already been done. */ if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE && (subshell_environment & SUBSHELL_PIPE) == 0) adjust_shell_level (-1); maybe_make_export_env (); put_command_name_into_env (command); } /* We have to make the child before we check for the non-existence of COMMAND, since we want the error messages to be redirected. */ /* If we can get away without forking and there are no pipes to deal with, don't bother to fork, just directly exec the command. */ if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE) pid = 0; else { fork_flags = async ? FORK_ASYNC : 0; pid = make_child (p = savestring (command_line), fork_flags); } if (pid == 0) { int old_interactive; reset_terminating_signals (); /* XXX */ /* Cancel traps, in trap.c. */ restore_original_signals (); subshell_environment &= ~SUBSHELL_IGNTRAP; #if defined (JOB_CONTROL) FREE (p); #endif /* restore_original_signals may have undone the work done by make_child to ensure that SIGINT and SIGQUIT are ignored in asynchronous children. */ if (async) { if ((cmdflags & CMD_STDIN_REDIR) && pipe_in == NO_PIPE && (stdin_redirects (redirects) == 0)) async_redirect_stdin (); setup_async_signals (); } /* This functionality is now provided by close-on-exec of the file descriptors manipulated by redirection and piping. Some file descriptors still need to be closed in all children because of the way bash does pipes; fds_to_close is a bitmap of all such file descriptors. */ if (fds_to_close) close_fd_bitmap (fds_to_close); do_piping (pipe_in, pipe_out); old_interactive = interactive; if (async) interactive = 0; subshell_environment |= SUBSHELL_FORK; /* XXX - was just = */ #if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD) clear_fifo_list (); /* XXX - we haven't created any FIFOs */ #endif /* reset shell_pgrp to pipeline_pgrp here for word expansions performed by the redirections here? */ if (redirects && (do_redirections (redirects, RX_ACTIVE) != 0)) { #if defined (PROCESS_SUBSTITUTION) /* Try to remove named pipes that may have been created as the result of redirections. */ unlink_all_fifos (); #endif /* PROCESS_SUBSTITUTION */ exit (EXECUTION_FAILURE); } #if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD) /* This should only contain FIFOs created as part of redirection expansion. */ unlink_all_fifos (); #endif if (async) interactive = old_interactive; if (command == 0) { hookf = find_function (NOTFOUND_HOOK); if (hookf == 0) { /* Make sure filenames are displayed using printable characters */ pathname = printable_filename (pathname, 0); internal_error (_("%s: command not found"), pathname); exit (EX_NOTFOUND); /* Posix.2 says the exit status is 127 */ } /* We don't want to manage process groups for processes we start from here, so we turn off job control and don't attempt to manipulate the terminal's process group. */ without_job_control (); #if defined (JOB_CONTROL) set_sigchld_handler (); #endif wl = make_word_list (make_word (NOTFOUND_HOOK), words); exit (execute_shell_function (hookf, wl)); } /* Execve expects the command name to be in args[0]. So we leave it there, in the same format that the user used to type it in. */ args = strvec_from_word_list (words, 0, 0, (int *)NULL); exit (shell_execve (command, args, export_env)); } else { parent_return: QUIT; /* Make sure that the pipes are closed in the parent. */ close_pipes (pipe_in, pipe_out); #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD) #if 0 if (variable_context == 0) unlink_fifo_list (); #endif #endif FREE (command); return (result); } } /* CPP defines to decide whether a particular index into the #! line corresponds to a valid interpreter name or argument character, or whitespace. The MSDOS define is to allow \r to be treated the same as \n. */ #if !defined (MSDOS) # define STRINGCHAR(ind) \ (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n') # define WHITECHAR(ind) \ (ind < sample_len && whitespace (sample[ind])) #else /* MSDOS */ # define STRINGCHAR(ind) \ (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n' && sample[ind] != '\r') # define WHITECHAR(ind) \ (ind < sample_len && whitespace (sample[ind])) #endif /* MSDOS */ static char * getinterp (sample, sample_len, endp) char *sample; int sample_len, *endp; { register int i; char *execname; int start; /* Find the name of the interpreter to exec. */ for (i = 2; i < sample_len && whitespace (sample[i]); i++) ; for (start = i; STRINGCHAR(i); i++) ; execname = substring (sample, start, i); if (endp) *endp = i; return execname; } #if !defined (HAVE_HASH_BANG_EXEC) /* If the operating system on which we're running does not handle the #! executable format, then help out. SAMPLE is the text read from the file, SAMPLE_LEN characters. COMMAND is the name of the script; it and ARGS, the arguments given by the user, will become arguments to the specified interpreter. ENV is the environment to pass to the interpreter. The word immediately following the #! is the interpreter to execute. A single argument to the interpreter is allowed. */ static int execute_shell_script (sample, sample_len, command, args, env) char *sample; int sample_len; char *command; char **args, **env; { char *execname, *firstarg; int i, start, size_increment, larry; /* Find the name of the interpreter to exec. */ execname = getinterp (sample, sample_len, &i); size_increment = 1; /* Now the argument, if any. */ for (firstarg = (char *)NULL, start = i; WHITECHAR(i); i++) ; /* If there is more text on the line, then it is an argument for the interpreter. */ if (STRINGCHAR(i)) { for (start = i; STRINGCHAR(i); i++) ; firstarg = substring ((char *)sample, start, i); size_increment = 2; } larry = strvec_len (args) + size_increment; args = strvec_resize (args, larry + 1); for (i = larry - 1; i; i--) args[i] = args[i - size_increment]; args[0] = execname; if (firstarg) { args[1] = firstarg; args[2] = command; } else args[1] = command; args[larry] = (char *)NULL; return (shell_execve (execname, args, env)); } #undef STRINGCHAR #undef WHITECHAR #endif /* !HAVE_HASH_BANG_EXEC */ static void initialize_subshell () { #if defined (ALIAS) /* Forget about any aliases that we knew of. We are in a subshell. */ delete_all_aliases (); #endif /* ALIAS */ #if defined (HISTORY) /* Forget about the history lines we have read. This is a non-interactive subshell. */ history_lines_this_session = 0; #endif /* Forget about the way job control was working. We are in a subshell. */ without_job_control (); #if defined (JOB_CONTROL) set_sigchld_handler (); init_job_stats (); #endif /* JOB_CONTROL */ /* Reset the values of the shell flags and options. */ reset_shell_flags (); reset_shell_options (); reset_shopt_options (); /* Zero out builtin_env, since this could be a shell script run from a sourced file with a temporary environment supplied to the `source/.' builtin. Such variables are not supposed to be exported (empirical testing with sh and ksh). Just throw it away; don't worry about a memory leak. */ if (vc_isbltnenv (shell_variables)) shell_variables = shell_variables->down; clear_unwind_protect_list (0); /* XXX -- are there other things we should be resetting here? */ parse_and_execute_level = 0; /* nothing left to restore it */ /* We're no longer inside a shell function. */ variable_context = return_catch_flag = funcnest = evalnest = sourcenest = 0; executing_list = 0; /* XXX */ /* If we're not interactive, close the file descriptor from which we're reading the current shell script. */ if (interactive_shell == 0) unset_bash_input (0); } #if defined (HAVE_SETOSTYPE) && defined (_POSIX_SOURCE) # define SETOSTYPE(x) __setostype(x) #else # define SETOSTYPE(x) #endif #define HASH_BANG_BUFSIZ 128 #define READ_SAMPLE_BUF(file, buf, len) \ do \ { \ fd = open(file, O_RDONLY); \ if (fd >= 0) \ { \ len = read (fd, buf, HASH_BANG_BUFSIZ); \ close (fd); \ } \ else \ len = -1; \ } \ while (0) /* Call execve (), handling interpreting shell scripts, and handling exec failures. */ int shell_execve (command, args, env) char *command; char **args, **env; { int larray, i, fd; char sample[HASH_BANG_BUFSIZ]; int sample_len; SETOSTYPE (0); /* Some systems use for USG/POSIX semantics */ execve (command, args, env); i = errno; /* error from execve() */ CHECK_TERMSIG; SETOSTYPE (1); /* If we get to this point, then start checking out the file. Maybe it is something we can hack ourselves. */ if (i != ENOEXEC) { /* make sure this is set correctly for file_error/report_error */ last_command_exit_value = (i == ENOENT) ? EX_NOTFOUND : EX_NOEXEC; /* XXX Posix.2 says that exit status is 126 */ if (file_isdir (command)) #if defined (EISDIR) internal_error (_("%s: %s"), command, strerror (EISDIR)); #else internal_error (_("%s: is a directory"), command); #endif else if (executable_file (command) == 0) { errno = i; file_error (command); } /* errors not involving the path argument to execve. */ else if (i == E2BIG || i == ENOMEM) { errno = i; file_error (command); } else if (i == ENOENT) { errno = i; internal_error (_("%s: cannot execute: required file not found"), command); } else { /* The file has the execute bits set, but the kernel refuses to run it for some reason. See why. */ #if defined (HAVE_HASH_BANG_EXEC) READ_SAMPLE_BUF (command, sample, sample_len); if (sample_len > 0) sample[sample_len - 1] = '\0'; if (sample_len > 2 && sample[0] == '#' && sample[1] == '!') { char *interp; int ilen; interp = getinterp (sample, sample_len, (int *)NULL); ilen = strlen (interp); errno = i; if (interp[ilen - 1] == '\r') { interp = xrealloc (interp, ilen + 2); interp[ilen - 1] = '^'; interp[ilen] = 'M'; interp[ilen + 1] = '\0'; } sys_error (_("%s: %s: bad interpreter"), command, interp ? interp : ""); FREE (interp); return (EX_NOEXEC); } #endif errno = i; file_error (command); } return (last_command_exit_value); } /* This file is executable. If it begins with #!, then help out people with losing operating systems. Otherwise, check to see if it is a binary file by seeing if the contents of the first line (or up to 80 characters) are in the ASCII set. If it's a text file, execute the contents as shell commands, otherwise return 126 (EX_BINARY_FILE). */ READ_SAMPLE_BUF (command, sample, sample_len); if (sample_len == 0) return (EXECUTION_SUCCESS); /* Is this supposed to be an executable script? If so, the format of the line is "#! interpreter [argument]". A single argument is allowed. The BSD kernel restricts the length of the entire line to 32 characters (32 bytes being the size of the BSD exec header), but we allow up to 128 characters. */ if (sample_len > 0) { #if !defined (HAVE_HASH_BANG_EXEC) if (sample_len > 2 && sample[0] == '#' && sample[1] == '!') return (execute_shell_script (sample, sample_len, command, args, env)); else #endif if (check_binary_file (sample, sample_len)) { internal_error (_("%s: cannot execute binary file: %s"), command, strerror (i)); errno = i; return (EX_BINARY_FILE); } } /* We have committed to attempting to execute the contents of this file as shell commands. */ reset_parser (); initialize_subshell (); set_sigint_handler (); /* Insert the name of this shell into the argument list. */ larray = strvec_len (args) + 1; args = strvec_resize (args, larray + 1); for (i = larray - 1; i; i--) args[i] = args[i - 1]; args[0] = shell_name; args[1] = command; args[larray] = (char *)NULL; if (args[0][0] == '-') args[0]++; #if defined (RESTRICTED_SHELL) if (restricted) change_flag ('r', FLAG_OFF); #endif if (subshell_argv) { /* Can't free subshell_argv[0]; that is shell_name. */ for (i = 1; i < subshell_argc; i++) free (subshell_argv[i]); free (subshell_argv); } dispose_command (currently_executing_command); /* XXX */ currently_executing_command = (COMMAND *)NULL; subshell_argc = larray; subshell_argv = args; subshell_envp = env; unbind_args (); /* remove the positional parameters */ #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD) clear_fifo_list (); /* pipe fds are what they are now */ #endif sh_longjmp (subshell_top_level, 1); /*NOTREACHED*/ } static int execute_intern_function (name, funcdef) WORD_DESC *name; FUNCTION_DEF *funcdef; { SHELL_VAR *var; char *t; if (check_identifier (name, posixly_correct) == 0) { if (posixly_correct && interactive_shell == 0) { last_command_exit_value = EX_BADUSAGE; jump_to_top_level (ERREXIT); } return (EXECUTION_FAILURE); } if (strchr (name->word, CTLESC)) /* WHY? */ { t = dequote_escapes (name->word); free (name->word); name->word = t; } /* Posix interpretation 383 */ if (posixly_correct && find_special_builtin (name->word)) { internal_error (_("`%s': is a special builtin"), name->word); last_command_exit_value = EX_BADUSAGE; jump_to_top_level (interactive_shell ? DISCARD : ERREXIT); } var = find_function (name->word); if (var && (readonly_p (var) || noassign_p (var))) { if (readonly_p (var)) internal_error (_("%s: readonly function"), var->name); return (EXECUTION_FAILURE); } #if defined (DEBUGGER) bind_function_def (name->word, funcdef, 1); #endif bind_function (name->word, funcdef->command); return (EXECUTION_SUCCESS); } #if defined (INCLUDE_UNUSED) #if defined (PROCESS_SUBSTITUTION) void close_all_files () { register int i, fd_table_size; fd_table_size = getdtablesize (); if (fd_table_size > 256) /* clamp to a reasonable value */ fd_table_size = 256; for (i = 3; i < fd_table_size; i++) close (i); } #endif /* PROCESS_SUBSTITUTION */ #endif static void close_pipes (in, out) int in, out; { if (in >= 0) close (in); if (out >= 0) close (out); } static void dup_error (oldd, newd) int oldd, newd; { sys_error (_("cannot duplicate fd %d to fd %d"), oldd, newd); } /* Redirect input and output to be from and to the specified pipes. NO_PIPE and REDIRECT_BOTH are handled correctly. */ static void do_piping (pipe_in, pipe_out) int pipe_in, pipe_out; { if (pipe_in != NO_PIPE) { if (dup2 (pipe_in, 0) < 0) dup_error (pipe_in, 0); if (pipe_in > 0) close (pipe_in); #ifdef __CYGWIN__ /* Let stdio know the fd may have changed from text to binary mode. */ freopen (NULL, "r", stdin); #endif /* __CYGWIN__ */ } if (pipe_out != NO_PIPE) { if (pipe_out != REDIRECT_BOTH) { if (dup2 (pipe_out, 1) < 0) dup_error (pipe_out, 1); if (pipe_out == 0 || pipe_out > 1) close (pipe_out); } else { if (dup2 (1, 2) < 0) dup_error (1, 2); } #ifdef __CYGWIN__ /* Let stdio know the fd may have changed from text to binary mode, and make sure to preserve stdout line buffering. */ freopen (NULL, "w", stdout); sh_setlinebuf (stdout); #endif /* __CYGWIN__ */ } }