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Diffstat (limited to 'flags.c')
| -rw-r--r-- | flags.c | 385 |
1 files changed, 385 insertions, 0 deletions
@@ -0,0 +1,385 @@ +/* flags.c -- Everything about flags except the `set' command. That + is in builtins.c */ + +/* Copyright (C) 1987-2020 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 <http://www.gnu.org/licenses/>. +*/ + +#include "config.h" +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "shell.h" +#include "execute_cmd.h" +#include "flags.h" + +#if defined (BANG_HISTORY) +# include "bashhist.h" +#endif + +#if defined (JOB_CONTROL) +extern int set_job_control PARAMS((int)); +#endif + +/* **************************************************************** */ +/* */ +/* The Standard sh Flags. */ +/* */ +/* **************************************************************** */ + +/* Non-zero means automatically mark variables which are modified or created + as auto export variables. */ +int mark_modified_vars = 0; + +/* Non-zero causes asynchronous job notification. Otherwise, job state + notification only takes place just before a primary prompt is printed. */ +int asynchronous_notification = 0; + +/* Non-zero means exit immediately if a command exits with a non-zero + exit status. The first is what controls set -e; the second is what + bash uses internally. */ +int errexit_flag = 0; +int exit_immediately_on_error = 0; + +/* Non-zero means disable filename globbing. */ +int disallow_filename_globbing = 0; + +/* Non-zero means that all keyword arguments are placed into the environment + for a command, not just those that appear on the line before the command + name. */ +int place_keywords_in_env = 0; + +/* Non-zero means read commands, but don't execute them. This is useful + for debugging shell scripts that should do something hairy and possibly + destructive. */ +int read_but_dont_execute = 0; + +/* Non-zero means end of file is after one command. */ +int just_one_command = 0; + +/* Non-zero means don't overwrite existing files while doing redirections. */ +int noclobber = 0; + +/* Non-zero means trying to get the value of $i where $i is undefined + causes an error, instead of a null substitution. */ +int unbound_vars_is_error = 0; + +/* Non-zero means type out input lines after you read them. */ +int echo_input_at_read = 0; +int verbose_flag = 0; + +/* Non-zero means type out the command definition after reading, but + before executing. */ +int echo_command_at_execute = 0; + +/* Non-zero means turn on the job control features. */ +int jobs_m_flag = 0; + +/* Non-zero means this shell is interactive, even if running under a + pipe. */ +int forced_interactive = 0; + +/* By default, follow the symbolic links as if they were real directories + while hacking the `cd' command. This means that `cd ..' moves up in + the string of symbolic links that make up the current directory, instead + of the absolute directory. The shell variable `nolinks' also controls + this flag. */ +int no_symbolic_links = 0; + +/* **************************************************************** */ +/* */ +/* Non-Standard Flags Follow Here. */ +/* */ +/* **************************************************************** */ + +#if 0 +/* Non-zero means do lexical scoping in the body of a FOR command. */ +int lexical_scoping = 0; +#endif + +/* Non-zero means look up and remember command names in a hash table, */ +int hashing_enabled = 1; + +#if defined (BANG_HISTORY) +/* Non-zero means that we are doing history expansion. The default. + This means !22 gets the 22nd line of history. */ +int history_expansion = HISTEXPAND_DEFAULT; +int histexp_flag = 0; +#endif /* BANG_HISTORY */ + +/* Non-zero means that we allow comments to appear in interactive commands. */ +int interactive_comments = 1; + +#if defined (RESTRICTED_SHELL) +/* Non-zero means that this shell is `restricted'. A restricted shell + disallows: changing directories, command or path names containing `/', + unsetting or resetting the values of $PATH and $SHELL, and any type of + output redirection. */ +int restricted = 0; /* currently restricted */ +int restricted_shell = 0; /* shell was started in restricted mode. */ +#endif /* RESTRICTED_SHELL */ + +/* Non-zero means that this shell is running in `privileged' mode. This + is required if the shell is to run setuid. If the `-p' option is + not supplied at startup, and the real and effective uids or gids + differ, disable_priv_mode is called to relinquish setuid status. */ +int privileged_mode = 0; + +#if defined (BRACE_EXPANSION) +/* Zero means to disable brace expansion: foo{a,b} -> fooa foob */ +int brace_expansion = 1; +#endif + +/* Non-zero means that shell functions inherit the DEBUG trap. */ +int function_trace_mode = 0; + +/* Non-zero means that shell functions inherit the ERR trap. */ +int error_trace_mode = 0; + +/* Non-zero means that the rightmost non-zero exit status in a pipeline + is the exit status of the entire pipeline. If each processes exits + with a 0 status, the status of the pipeline is 0. */ +int pipefail_opt = 0; + +/* **************************************************************** */ +/* */ +/* The Flags ALIST. */ +/* */ +/* **************************************************************** */ + +const struct flags_alist shell_flags[] = { + /* Standard sh flags. */ + { 'a', &mark_modified_vars }, +#if defined (JOB_CONTROL) + { 'b', &asynchronous_notification }, +#endif /* JOB_CONTROL */ + { 'e', &errexit_flag }, + { 'f', &disallow_filename_globbing }, + { 'h', &hashing_enabled }, + { 'i', &forced_interactive }, + { 'k', &place_keywords_in_env }, +#if defined (JOB_CONTROL) + { 'm', &jobs_m_flag }, +#endif /* JOB_CONTROL */ + { 'n', &read_but_dont_execute }, + { 'p', &privileged_mode }, +#if defined (RESTRICTED_SHELL) + { 'r', &restricted }, +#endif /* RESTRICTED_SHELL */ + { 't', &just_one_command }, + { 'u', &unbound_vars_is_error }, + { 'v', &verbose_flag }, + { 'x', &echo_command_at_execute }, + + /* New flags that control non-standard things. */ +#if 0 + { 'l', &lexical_scoping }, +#endif +#if defined (BRACE_EXPANSION) + { 'B', &brace_expansion }, +#endif + { 'C', &noclobber }, + { 'E', &error_trace_mode }, +#if defined (BANG_HISTORY) + { 'H', &histexp_flag }, +#endif /* BANG_HISTORY */ + { 'P', &no_symbolic_links }, + { 'T', &function_trace_mode }, + {0, (int *)NULL} +}; + +#define NUM_SHELL_FLAGS (sizeof (shell_flags) / sizeof (struct flags_alist)) + +char optflags[NUM_SHELL_FLAGS+4] = { '+' }; + +int * +find_flag (name) + int name; +{ + int i; + for (i = 0; shell_flags[i].name; i++) + { + if (shell_flags[i].name == name) + return (shell_flags[i].value); + } + return (FLAG_UNKNOWN); +} + +/* Change the state of a flag, and return it's original value, or return + FLAG_ERROR if there is no flag FLAG. ON_OR_OFF must be either + FLAG_ON or FLAG_OFF. */ +int +change_flag (flag, on_or_off) + int flag; + int on_or_off; +{ + int *value, old_value; + +#if defined (RESTRICTED_SHELL) + /* Don't allow "set +r" in a shell which is `restricted'. */ + if (restricted && flag == 'r' && on_or_off == FLAG_OFF) + return (FLAG_ERROR); +#endif /* RESTRICTED_SHELL */ + + value = find_flag (flag); + + if ((value == (int *)FLAG_UNKNOWN) || (on_or_off != FLAG_ON && on_or_off != FLAG_OFF)) + return (FLAG_ERROR); + + old_value = *value; + *value = (on_or_off == FLAG_ON) ? 1 : 0; + + /* Special cases for a few flags. */ + switch (flag) + { +#if defined (BANG_HISTORY) + case 'H': + history_expansion = histexp_flag; + if (on_or_off == FLAG_ON) + bash_initialize_history (); + break; +#endif + +#if defined (JOB_CONTROL) + case 'm': + set_job_control (on_or_off == FLAG_ON); + break; +#endif /* JOB_CONTROL */ + + case 'e': + if (builtin_ignoring_errexit == 0) + exit_immediately_on_error = errexit_flag; + break; + + case 'n': + if (interactive_shell) + read_but_dont_execute = 0; + break; + + case 'p': + if (on_or_off == FLAG_OFF) + disable_priv_mode (); + break; + +#if defined (RESTRICTED_SHELL) + case 'r': + if (on_or_off == FLAG_ON && shell_initialized) + maybe_make_restricted (shell_name); + break; +#endif + + case 'v': + echo_input_at_read = verbose_flag; + break; + } + + return (old_value); +} + +/* Return a string which is the names of all the currently + set shell flags. */ +char * +which_set_flags () +{ + char *temp; + int i, string_index; + + temp = (char *)xmalloc (1 + NUM_SHELL_FLAGS + read_from_stdin + want_pending_command); + for (i = string_index = 0; shell_flags[i].name; i++) + if (*(shell_flags[i].value)) + temp[string_index++] = shell_flags[i].name; + + if (want_pending_command) + temp[string_index++] = 'c'; + if (read_from_stdin) + temp[string_index++] = 's'; + + temp[string_index] = '\0'; + return (temp); +} + +char * +get_current_flags () +{ + char *temp; + int i; + + temp = (char *)xmalloc (1 + NUM_SHELL_FLAGS); + for (i = 0; shell_flags[i].name; i++) + temp[i] = *(shell_flags[i].value); + temp[i] = '\0'; + return (temp); +} + +void +set_current_flags (bitmap) + const char *bitmap; +{ + int i; + + if (bitmap == 0) + return; + for (i = 0; shell_flags[i].name; i++) + *(shell_flags[i].value) = bitmap[i]; +} + +void +reset_shell_flags () +{ + mark_modified_vars = disallow_filename_globbing = 0; + place_keywords_in_env = read_but_dont_execute = just_one_command = 0; + noclobber = unbound_vars_is_error = 0; + echo_command_at_execute = jobs_m_flag = forced_interactive = 0; + no_symbolic_links = 0; + privileged_mode = pipefail_opt = 0; + + error_trace_mode = function_trace_mode = 0; + + exit_immediately_on_error = errexit_flag = 0; + echo_input_at_read = verbose_flag = 0; + + hashing_enabled = interactive_comments = 1; + +#if defined (JOB_CONTROL) + asynchronous_notification = 0; +#endif + +#if defined (BANG_HISTORY) + histexp_flag = 0; +#endif + +#if defined (BRACE_EXPANSION) + brace_expansion = 1; +#endif + +#if defined (RESTRICTED_SHELL) + restricted = 0; +#endif +} + +void +initialize_flags () +{ + register int i; + + for (i = 0; shell_flags[i].name; i++) + optflags[i+1] = shell_flags[i].name; + optflags[++i] = 'o'; + optflags[++i] = ';'; + optflags[i+1] = '\0'; +} |