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[bash.git] / flags.c
blobd3b38ad37b24d95cdfd5a4a0eb4e0413807d1c49
1 /* flags.c -- Everything about flags except the `set' command. That
2 is in builtins.c */
4 /* Copyright (C) 1987-2009 Free Software Foundation, Inc.
6 This file is part of GNU Bash, the Bourne Again SHell.
8 Bash is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 Bash is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with Bash. If not, see <http://www.gnu.org/licenses/>.
22 #include "config.h"
23 #if defined (HAVE_UNISTD_H)
24 # include <unistd.h>
25 #endif
27 #include "shell.h"
28 #include "flags.h"
30 #if defined (BANG_HISTORY)
31 # include "bashhist.h"
32 #endif
34 #if defined (JOB_CONTROL)
35 extern int set_job_control __P((int));
36 #endif
38 #if defined (RESTRICTED_SHELL)
39 extern char *shell_name;
40 #endif
42 extern int shell_initialized;
44 /* -c, -s invocation options -- not really flags, but they show up in $- */
45 extern int want_pending_command, read_from_stdin;
47 /* **************************************************************** */
48 /* */
49 /* The Standard sh Flags. */
50 /* */
51 /* **************************************************************** */
53 /* Non-zero means automatically mark variables which are modified or created
54 as auto export variables. */
55 int mark_modified_vars = 0;
57 /* Non-zero causes asynchronous job notification. Otherwise, job state
58 notification only takes place just before a primary prompt is printed. */
59 int asynchronous_notification = 0;
61 /* Non-zero means exit immediately if a command exits with a non-zero
62 exit status. */
63 int exit_immediately_on_error = 0;
65 /* Non-zero means disable filename globbing. */
66 int disallow_filename_globbing = 0;
68 /* Non-zero means that all keyword arguments are placed into the environment
69 for a command, not just those that appear on the line before the command
70 name. */
71 int place_keywords_in_env = 0;
73 /* Non-zero means read commands, but don't execute them. This is useful
74 for debugging shell scripts that should do something hairy and possibly
75 destructive. */
76 int read_but_dont_execute = 0;
78 /* Non-zero means end of file is after one command. */
79 int just_one_command = 0;
81 /* Non-zero means don't overwrite existing files while doing redirections. */
82 int noclobber = 0;
84 /* Non-zero means trying to get the value of $i where $i is undefined
85 causes an error, instead of a null substitution. */
86 int unbound_vars_is_error = 0;
88 /* Non-zero means type out input lines after you read them. */
89 int echo_input_at_read = 0;
91 /* Non-zero means type out the command definition after reading, but
92 before executing. */
93 int echo_command_at_execute = 0;
95 /* Non-zero means turn on the job control features. */
96 int jobs_m_flag = 0;
98 /* Non-zero means this shell is interactive, even if running under a
99 pipe. */
100 int forced_interactive = 0;
102 /* By default, follow the symbolic links as if they were real directories
103 while hacking the `cd' command. This means that `cd ..' moves up in
104 the string of symbolic links that make up the current directory, instead
105 of the absolute directory. The shell variable `nolinks' also controls
106 this flag. */
107 int no_symbolic_links = 0;
109 /* **************************************************************** */
110 /* */
111 /* Non-Standard Flags Follow Here. */
112 /* */
113 /* **************************************************************** */
115 #if 0
116 /* Non-zero means do lexical scoping in the body of a FOR command. */
117 int lexical_scoping = 0;
118 #endif
120 /* Non-zero means no such thing as invisible variables. */
121 int no_invisible_vars = 0;
123 /* Non-zero means look up and remember command names in a hash table, */
124 int hashing_enabled = 1;
126 #if defined (BANG_HISTORY)
127 /* Non-zero means that we are doing history expansion. The default.
128 This means !22 gets the 22nd line of history. */
129 int history_expansion = 1;
130 #endif /* BANG_HISTORY */
132 /* Non-zero means that we allow comments to appear in interactive commands. */
133 int interactive_comments = 1;
135 #if defined (RESTRICTED_SHELL)
136 /* Non-zero means that this shell is `restricted'. A restricted shell
137 disallows: changing directories, command or path names containing `/',
138 unsetting or resetting the values of $PATH and $SHELL, and any type of
139 output redirection. */
140 int restricted = 0; /* currently restricted */
141 int restricted_shell = 0; /* shell was started in restricted mode. */
142 #endif /* RESTRICTED_SHELL */
144 /* Non-zero means that this shell is running in `privileged' mode. This
145 is required if the shell is to run setuid. If the `-p' option is
146 not supplied at startup, and the real and effective uids or gids
147 differ, disable_priv_mode is called to relinquish setuid status. */
148 int privileged_mode = 0;
150 #if defined (BRACE_EXPANSION)
151 /* Zero means to disable brace expansion: foo{a,b} -> fooa foob */
152 int brace_expansion = 1;
153 #endif
155 /* Non-zero means that shell functions inherit the DEBUG trap. */
156 int function_trace_mode = 0;
158 /* Non-zero means that shell functions inherit the ERR trap. */
159 int error_trace_mode = 0;
161 /* Non-zero means that the rightmost non-zero exit status in a pipeline
162 is the exit status of the entire pipeline. If each processes exits
163 with a 0 status, the status of the pipeline is 0. */
164 int pipefail_opt = 0;
166 /* **************************************************************** */
167 /* */
168 /* The Flags ALIST. */
169 /* */
170 /* **************************************************************** */
172 const struct flags_alist shell_flags[] = {
173 /* Standard sh flags. */
174 { 'a', &mark_modified_vars },
175 #if defined (JOB_CONTROL)
176 { 'b', &asynchronous_notification },
177 #endif /* JOB_CONTROL */
178 { 'e', &exit_immediately_on_error },
179 { 'f', &disallow_filename_globbing },
180 { 'h', &hashing_enabled },
181 { 'i', &forced_interactive },
182 { 'k', &place_keywords_in_env },
183 #if defined (JOB_CONTROL)
184 { 'm', &jobs_m_flag },
185 #endif /* JOB_CONTROL */
186 { 'n', &read_but_dont_execute },
187 { 'p', &privileged_mode },
188 #if defined (RESTRICTED_SHELL)
189 { 'r', &restricted },
190 #endif /* RESTRICTED_SHELL */
191 { 't', &just_one_command },
192 { 'u', &unbound_vars_is_error },
193 { 'v', &echo_input_at_read },
194 { 'x', &echo_command_at_execute },
196 /* New flags that control non-standard things. */
197 #if 0
198 { 'l', &lexical_scoping },
199 #endif
200 #if defined (BRACE_EXPANSION)
201 { 'B', &brace_expansion },
202 #endif
203 { 'C', &noclobber },
204 { 'E', &error_trace_mode },
205 #if defined (BANG_HISTORY)
206 { 'H', &history_expansion },
207 #endif /* BANG_HISTORY */
208 { 'I', &no_invisible_vars },
209 { 'P', &no_symbolic_links },
210 { 'T', &function_trace_mode },
211 {0, (int *)NULL}
214 #define NUM_SHELL_FLAGS (sizeof (shell_flags) / sizeof (struct flags_alist))
216 char optflags[NUM_SHELL_FLAGS+4] = { '+' };
218 int *
219 find_flag (name)
220 int name;
222 int i;
223 for (i = 0; shell_flags[i].name; i++)
225 if (shell_flags[i].name == name)
226 return (shell_flags[i].value);
228 return (FLAG_UNKNOWN);
231 /* Change the state of a flag, and return it's original value, or return
232 FLAG_ERROR if there is no flag FLAG. ON_OR_OFF must be either
233 FLAG_ON or FLAG_OFF. */
235 change_flag (flag, on_or_off)
236 int flag;
237 int on_or_off;
239 int *value, old_value;
241 #if defined (RESTRICTED_SHELL)
242 /* Don't allow "set +r" in a shell which is `restricted'. */
243 if (restricted && flag == 'r' && on_or_off == FLAG_OFF)
244 return (FLAG_ERROR);
245 #endif /* RESTRICTED_SHELL */
247 value = find_flag (flag);
249 if ((value == (int *)FLAG_UNKNOWN) || (on_or_off != FLAG_ON && on_or_off != FLAG_OFF))
250 return (FLAG_ERROR);
252 old_value = *value;
254 *value = (on_or_off == FLAG_ON) ? 1 : 0;
256 /* Special cases for a few flags. */
257 switch (flag)
259 #if defined (BANG_HISTORY)
260 case 'H':
261 if (on_or_off == FLAG_ON)
262 bash_initialize_history ();
263 break;
264 #endif
266 #if defined (JOB_CONTROL)
267 case 'm':
268 set_job_control (on_or_off == FLAG_ON);
269 break;
270 #endif /* JOB_CONTROL */
272 case 'n':
273 if (interactive_shell)
274 read_but_dont_execute = 0;
275 break;
277 case 'p':
278 if (on_or_off == FLAG_OFF)
279 disable_priv_mode ();
280 break;
282 #if defined (RESTRICTED_SHELL)
283 case 'r':
284 if (on_or_off == FLAG_ON && shell_initialized)
285 maybe_make_restricted (shell_name);
286 break;
287 #endif
291 return (old_value);
294 /* Return a string which is the names of all the currently
295 set shell flags. */
296 char *
297 which_set_flags ()
299 char *temp;
300 int i, string_index;
302 temp = (char *)xmalloc (1 + NUM_SHELL_FLAGS + read_from_stdin + want_pending_command);
303 for (i = string_index = 0; shell_flags[i].name; i++)
304 if (*(shell_flags[i].value))
305 temp[string_index++] = shell_flags[i].name;
307 if (want_pending_command)
308 temp[string_index++] = 'c';
309 if (read_from_stdin)
310 temp[string_index++] = 's';
312 temp[string_index] = '\0';
313 return (temp);
316 void
317 reset_shell_flags ()
319 mark_modified_vars = exit_immediately_on_error = disallow_filename_globbing = 0;
320 place_keywords_in_env = read_but_dont_execute = just_one_command = 0;
321 noclobber = unbound_vars_is_error = echo_input_at_read = 0;
322 echo_command_at_execute = jobs_m_flag = forced_interactive = 0;
323 no_symbolic_links = no_invisible_vars = privileged_mode = pipefail_opt = 0;
325 hashing_enabled = interactive_comments = 1;
327 #if defined (JOB_CONTROL)
328 asynchronous_notification = 0;
329 #endif
331 #if defined (BANG_HISTORY)
332 history_expansion = 1;
333 #endif
335 #if defined (BRACE_EXPANSION)
336 brace_expansion = 1;
337 #endif
339 #if defined (RESTRICTED_SHELL)
340 restricted = 0;
341 #endif
344 void
345 initialize_flags ()
347 register int i;
349 for (i = 0; shell_flags[i].name; i++)
350 optflags[i+1] = shell_flags[i].name;
351 optflags[++i] = 'o';
352 optflags[++i] = ';';
353 optflags[i+1] = '\0';