1 /* flags.c -- Everything about flags except the `set' command. That
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/>.
23 #if defined (HAVE_UNISTD_H)
30 #if defined (BANG_HISTORY)
31 # include "bashhist.h"
34 #if defined (JOB_CONTROL)
35 extern int set_job_control
__P((int));
38 #if defined (RESTRICTED_SHELL)
39 extern char *shell_name
;
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 /* **************************************************************** */
49 /* The Standard sh Flags. */
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
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
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
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. */
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
93 int echo_command_at_execute
= 0;
95 /* Non-zero means turn on the job control features. */
98 /* Non-zero means this shell is interactive, even if running under a
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
107 int no_symbolic_links
= 0;
109 /* **************************************************************** */
111 /* Non-Standard Flags Follow Here. */
113 /* **************************************************************** */
116 /* Non-zero means do lexical scoping in the body of a FOR command. */
117 int lexical_scoping
= 0;
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 # if defined (STRICT_POSIX)
130 int history_expansion
= 0;
132 int history_expansion
= 1;
134 #endif /* BANG_HISTORY */
136 /* Non-zero means that we allow comments to appear in interactive commands. */
137 int interactive_comments
= 1;
139 #if defined (RESTRICTED_SHELL)
140 /* Non-zero means that this shell is `restricted'. A restricted shell
141 disallows: changing directories, command or path names containing `/',
142 unsetting or resetting the values of $PATH and $SHELL, and any type of
143 output redirection. */
144 int restricted
= 0; /* currently restricted */
145 int restricted_shell
= 0; /* shell was started in restricted mode. */
146 #endif /* RESTRICTED_SHELL */
148 /* Non-zero means that this shell is running in `privileged' mode. This
149 is required if the shell is to run setuid. If the `-p' option is
150 not supplied at startup, and the real and effective uids or gids
151 differ, disable_priv_mode is called to relinquish setuid status. */
152 int privileged_mode
= 0;
154 #if defined (BRACE_EXPANSION)
155 /* Zero means to disable brace expansion: foo{a,b} -> fooa foob */
156 int brace_expansion
= 1;
159 /* Non-zero means that shell functions inherit the DEBUG trap. */
160 int function_trace_mode
= 0;
162 /* Non-zero means that shell functions inherit the ERR trap. */
163 int error_trace_mode
= 0;
165 /* Non-zero means that the rightmost non-zero exit status in a pipeline
166 is the exit status of the entire pipeline. If each processes exits
167 with a 0 status, the status of the pipeline is 0. */
168 int pipefail_opt
= 0;
170 /* **************************************************************** */
172 /* The Flags ALIST. */
174 /* **************************************************************** */
176 const struct flags_alist shell_flags
[] = {
177 /* Standard sh flags. */
178 { 'a', &mark_modified_vars
},
179 #if defined (JOB_CONTROL)
180 { 'b', &asynchronous_notification
},
181 #endif /* JOB_CONTROL */
182 { 'e', &exit_immediately_on_error
},
183 { 'f', &disallow_filename_globbing
},
184 { 'h', &hashing_enabled
},
185 { 'i', &forced_interactive
},
186 { 'k', &place_keywords_in_env
},
187 #if defined (JOB_CONTROL)
188 { 'm', &jobs_m_flag
},
189 #endif /* JOB_CONTROL */
190 { 'n', &read_but_dont_execute
},
191 { 'p', &privileged_mode
},
192 #if defined (RESTRICTED_SHELL)
193 { 'r', &restricted
},
194 #endif /* RESTRICTED_SHELL */
195 { 't', &just_one_command
},
196 { 'u', &unbound_vars_is_error
},
197 { 'v', &echo_input_at_read
},
198 { 'x', &echo_command_at_execute
},
200 /* New flags that control non-standard things. */
202 { 'l', &lexical_scoping
},
204 #if defined (BRACE_EXPANSION)
205 { 'B', &brace_expansion
},
208 { 'E', &error_trace_mode
},
209 #if defined (BANG_HISTORY)
210 { 'H', &history_expansion
},
211 #endif /* BANG_HISTORY */
212 { 'I', &no_invisible_vars
},
213 { 'P', &no_symbolic_links
},
214 { 'T', &function_trace_mode
},
218 #define NUM_SHELL_FLAGS (sizeof (shell_flags) / sizeof (struct flags_alist))
220 char optflags
[NUM_SHELL_FLAGS
+4] = { '+' };
227 for (i
= 0; shell_flags
[i
].name
; i
++)
229 if (shell_flags
[i
].name
== name
)
230 return (shell_flags
[i
].value
);
232 return (FLAG_UNKNOWN
);
235 /* Change the state of a flag, and return it's original value, or return
236 FLAG_ERROR if there is no flag FLAG. ON_OR_OFF must be either
237 FLAG_ON or FLAG_OFF. */
239 change_flag (flag
, on_or_off
)
243 int *value
, old_value
;
245 #if defined (RESTRICTED_SHELL)
246 /* Don't allow "set +r" in a shell which is `restricted'. */
247 if (restricted
&& flag
== 'r' && on_or_off
== FLAG_OFF
)
249 #endif /* RESTRICTED_SHELL */
251 value
= find_flag (flag
);
253 if ((value
== (int *)FLAG_UNKNOWN
) || (on_or_off
!= FLAG_ON
&& on_or_off
!= FLAG_OFF
))
257 *value
= (on_or_off
== FLAG_ON
) ? 1 : 0;
259 /* Special cases for a few flags. */
262 #if defined (BANG_HISTORY)
264 if (on_or_off
== FLAG_ON
)
265 bash_initialize_history ();
269 #if defined (JOB_CONTROL)
271 set_job_control (on_or_off
== FLAG_ON
);
273 #endif /* JOB_CONTROL */
276 if (interactive_shell
)
277 read_but_dont_execute
= 0;
281 if (on_or_off
== FLAG_OFF
)
282 disable_priv_mode ();
285 #if defined (RESTRICTED_SHELL)
287 if (on_or_off
== FLAG_ON
&& shell_initialized
)
288 maybe_make_restricted (shell_name
);
297 /* Return a string which is the names of all the currently
305 temp
= (char *)xmalloc (1 + NUM_SHELL_FLAGS
+ read_from_stdin
+ want_pending_command
);
306 for (i
= string_index
= 0; shell_flags
[i
].name
; i
++)
307 if (*(shell_flags
[i
].value
))
308 temp
[string_index
++] = shell_flags
[i
].name
;
310 if (want_pending_command
)
311 temp
[string_index
++] = 'c';
313 temp
[string_index
++] = 's';
315 temp
[string_index
] = '\0';
322 mark_modified_vars
= exit_immediately_on_error
= disallow_filename_globbing
= 0;
323 place_keywords_in_env
= read_but_dont_execute
= just_one_command
= 0;
324 noclobber
= unbound_vars_is_error
= echo_input_at_read
= 0;
325 echo_command_at_execute
= jobs_m_flag
= forced_interactive
= 0;
326 no_symbolic_links
= no_invisible_vars
= privileged_mode
= pipefail_opt
= 0;
328 hashing_enabled
= interactive_comments
= 1;
330 #if defined (JOB_CONTROL)
331 asynchronous_notification
= 0;
334 #if defined (BANG_HISTORY)
335 history_expansion
= 1;
338 #if defined (BRACE_EXPANSION)
342 #if defined (RESTRICTED_SHELL)
352 for (i
= 0; shell_flags
[i
].name
; i
++)
353 optflags
[i
+1] = shell_flags
[i
].name
;
356 optflags
[i
+1] = '\0';