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Commit | Line | Data |
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bb70624e | 1 | /* eval.c -- reading and evaluating commands. */ |
ccc6cda3 | 2 | |
712f80b0 | 3 | /* Copyright (C) 1996-2020 Free Software Foundation, Inc. |
ccc6cda3 | 4 | |
bb70624e | 5 | This file is part of GNU Bash, the Bourne Again SHell. |
ccc6cda3 | 6 | |
3185942a JA |
7 | Bash is free software: you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation, either version 3 of the License, or | |
10 | (at your option) any later version. | |
ccc6cda3 | 11 | |
3185942a JA |
12 | Bash is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
ccc6cda3 | 16 | |
bb70624e | 17 | You should have received a copy of the GNU General Public License |
3185942a JA |
18 | along with Bash. If not, see <http://www.gnu.org/licenses/>. |
19 | */ | |
ccc6cda3 JA |
20 | |
21 | #include "config.h" | |
22 | ||
23 | #if defined (HAVE_UNISTD_H) | |
cce855bc JA |
24 | # ifdef _MINIX |
25 | # include <sys/types.h> | |
26 | # endif | |
ccc6cda3 JA |
27 | # include <unistd.h> |
28 | #endif | |
29 | ||
30 | #include "bashansi.h" | |
31 | #include <stdio.h> | |
32 | ||
a0c0a00f CR |
33 | #include <signal.h> |
34 | ||
b80f6443 JA |
35 | #include "bashintl.h" |
36 | ||
ccc6cda3 | 37 | #include "shell.h" |
d233b485 | 38 | #include "parser.h" |
ccc6cda3 JA |
39 | #include "flags.h" |
40 | #include "trap.h" | |
41 | ||
42 | #include "builtins/common.h" | |
43 | ||
44 | #include "input.h" | |
45 | #include "execute_cmd.h" | |
46 | ||
b72432fd JA |
47 | #if defined (HISTORY) |
48 | # include "bashhist.h" | |
49 | #endif | |
50 | ||
712f80b0 CR |
51 | static void send_pwd_to_eterm PARAMS((void)); |
52 | static sighandler alrm_catcher PARAMS((int)); | |
7117c2d2 | 53 | |
ccc6cda3 JA |
54 | /* Read and execute commands until EOF is reached. This assumes that |
55 | the input source has already been initialized. */ | |
56 | int | |
57 | reader_loop () | |
58 | { | |
59 | int our_indirection_level; | |
95732b49 | 60 | COMMAND * volatile current_command; |
ccc6cda3 | 61 | |
f73dda09 JA |
62 | USE_VAR(current_command); |
63 | ||
3185942a JA |
64 | current_command = (COMMAND *)NULL; |
65 | ||
ccc6cda3 JA |
66 | our_indirection_level = ++indirection_level; |
67 | ||
d233b485 CR |
68 | if (just_one_command) |
69 | reset_readahead_token (); | |
70 | ||
ccc6cda3 JA |
71 | while (EOF_Reached == 0) |
72 | { | |
73 | int code; | |
74 | ||
ac50fbac | 75 | code = setjmp_nosigs (top_level); |
ccc6cda3 JA |
76 | |
77 | #if defined (PROCESS_SUBSTITUTION) | |
78 | unlink_fifo_list (); | |
79 | #endif /* PROCESS_SUBSTITUTION */ | |
80 | ||
a0c0a00f CR |
81 | /* XXX - why do we set this every time through the loop? And why do |
82 | it if SIGINT is trapped in an interactive shell? */ | |
d233b485 | 83 | if (interactive_shell && signal_is_ignored (SIGINT) == 0 && signal_is_trapped (SIGINT) == 0) |
ccc6cda3 JA |
84 | set_signal_handler (SIGINT, sigint_sighandler); |
85 | ||
86 | if (code != NOT_JUMPED) | |
87 | { | |
88 | indirection_level = our_indirection_level; | |
89 | ||
90 | switch (code) | |
91 | { | |
ac50fbac | 92 | /* Some kind of throw to top_level has occurred. */ |
ccc6cda3 | 93 | case FORCE_EOF: |
b80f6443 | 94 | case ERREXIT: |
ccc6cda3 JA |
95 | case EXITPROG: |
96 | current_command = (COMMAND *)NULL; | |
bb70624e JA |
97 | if (exit_immediately_on_error) |
98 | variable_context = 0; /* not in a function */ | |
ccc6cda3 JA |
99 | EOF_Reached = EOF; |
100 | goto exec_done; | |
101 | ||
102 | case DISCARD: | |
3185942a JA |
103 | /* Make sure the exit status is reset to a non-zero value, but |
104 | leave existing non-zero values (e.g., > 128 on signal) | |
105 | alone. */ | |
106 | if (last_command_exit_value == 0) | |
712f80b0 | 107 | set_exit_status (EXECUTION_FAILURE); |
ccc6cda3 JA |
108 | if (subshell_environment) |
109 | { | |
110 | current_command = (COMMAND *)NULL; | |
111 | EOF_Reached = EOF; | |
112 | goto exec_done; | |
113 | } | |
114 | /* Obstack free command elements, etc. */ | |
115 | if (current_command) | |
116 | { | |
117 | dispose_command (current_command); | |
118 | current_command = (COMMAND *)NULL; | |
119 | } | |
712f80b0 CR |
120 | |
121 | restore_sigmask (); | |
ccc6cda3 JA |
122 | break; |
123 | ||
124 | default: | |
b72432fd | 125 | command_error ("reader_loop", CMDERR_BADJUMP, code, 0); |
ccc6cda3 JA |
126 | } |
127 | } | |
128 | ||
129 | executing = 0; | |
7117c2d2 JA |
130 | if (temporary_env) |
131 | dispose_used_env_vars (); | |
ccc6cda3 JA |
132 | |
133 | #if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA) | |
134 | /* Attempt to reclaim memory allocated with alloca (). */ | |
135 | (void) alloca (0); | |
136 | #endif | |
137 | ||
138 | if (read_command () == 0) | |
139 | { | |
140 | if (interactive_shell == 0 && read_but_dont_execute) | |
141 | { | |
712f80b0 | 142 | set_exit_status (EXECUTION_SUCCESS); |
ccc6cda3 JA |
143 | dispose_command (global_command); |
144 | global_command = (COMMAND *)NULL; | |
145 | } | |
146 | else if (current_command = global_command) | |
147 | { | |
148 | global_command = (COMMAND *)NULL; | |
a0c0a00f CR |
149 | |
150 | /* If the shell is interactive, expand and display $PS0 after reading a | |
151 | command (possibly a list or pipeline) and before executing it. */ | |
152 | if (interactive && ps0_prompt) | |
153 | { | |
154 | char *ps0_string; | |
155 | ||
156 | ps0_string = decode_prompt_string (ps0_prompt); | |
157 | if (ps0_string && *ps0_string) | |
158 | { | |
159 | fprintf (stderr, "%s", ps0_string); | |
160 | fflush (stderr); | |
161 | } | |
162 | free (ps0_string); | |
163 | } | |
164 | ||
d233b485 CR |
165 | current_command_number++; |
166 | ||
167 | executing = 1; | |
168 | stdin_redir = 0; | |
169 | ||
ccc6cda3 JA |
170 | execute_command (current_command); |
171 | ||
172 | exec_done: | |
95732b49 JA |
173 | QUIT; |
174 | ||
ccc6cda3 | 175 | if (current_command) |
28ef6c31 | 176 | { |
ccc6cda3 JA |
177 | dispose_command (current_command); |
178 | current_command = (COMMAND *)NULL; | |
28ef6c31 | 179 | } |
ccc6cda3 JA |
180 | } |
181 | } | |
182 | else | |
183 | { | |
184 | /* Parse error, maybe discard rest of stream if not interactive. */ | |
185 | if (interactive == 0) | |
186 | EOF_Reached = EOF; | |
187 | } | |
188 | if (just_one_command) | |
189 | EOF_Reached = EOF; | |
190 | } | |
191 | indirection_level--; | |
192 | return (last_command_exit_value); | |
193 | } | |
194 | ||
d233b485 CR |
195 | /* Pretty print shell scripts */ |
196 | int | |
197 | pretty_print_loop () | |
198 | { | |
199 | COMMAND *current_command; | |
200 | char *command_to_print; | |
201 | int code; | |
202 | int global_posix_mode, last_was_newline; | |
203 | ||
204 | global_posix_mode = posixly_correct; | |
205 | last_was_newline = 0; | |
206 | while (EOF_Reached == 0) | |
207 | { | |
208 | code = setjmp_nosigs (top_level); | |
209 | if (code) | |
210 | return (EXECUTION_FAILURE); | |
211 | if (read_command() == 0) | |
212 | { | |
213 | current_command = global_command; | |
214 | global_command = 0; | |
215 | posixly_correct = 1; /* print posix-conformant */ | |
216 | if (current_command && (command_to_print = make_command_string (current_command))) | |
217 | { | |
218 | printf ("%s\n", command_to_print); /* for now */ | |
219 | last_was_newline = 0; | |
220 | } | |
221 | else if (last_was_newline == 0) | |
222 | { | |
223 | printf ("\n"); | |
224 | last_was_newline = 1; | |
225 | } | |
226 | posixly_correct = global_posix_mode; | |
227 | dispose_command (current_command); | |
228 | } | |
229 | else | |
230 | return (EXECUTION_FAILURE); | |
231 | } | |
232 | ||
233 | return (EXECUTION_SUCCESS); | |
234 | } | |
235 | ||
ccc6cda3 JA |
236 | static sighandler |
237 | alrm_catcher(i) | |
238 | int i; | |
239 | { | |
3eb0018e CR |
240 | char *msg; |
241 | ||
242 | msg = _("\007timed out waiting for input: auto-logout\n"); | |
243 | write (1, msg, strlen (msg)); | |
244 | ||
b80f6443 | 245 | bash_logout (); /* run ~/.bash_logout if this is a login shell */ |
ccc6cda3 JA |
246 | jump_to_top_level (EXITPROG); |
247 | SIGRETURN (0); | |
248 | } | |
249 | ||
250 | /* Send an escape sequence to emacs term mode to tell it the | |
251 | current working directory. */ | |
252 | static void | |
253 | send_pwd_to_eterm () | |
254 | { | |
ac50fbac | 255 | char *pwd, *f; |
ccc6cda3 | 256 | |
ac50fbac | 257 | f = 0; |
ccc6cda3 JA |
258 | pwd = get_string_value ("PWD"); |
259 | if (pwd == 0) | |
ac50fbac | 260 | f = pwd = get_working_directory ("eterm"); |
ccc6cda3 | 261 | fprintf (stderr, "\032/%s\n", pwd); |
ac50fbac | 262 | free (f); |
ccc6cda3 JA |
263 | } |
264 | ||
712f80b0 | 265 | #if defined (ARRAY_VARS) |
3eb0018e | 266 | /* Caller ensures that A has a non-zero number of elements */ |
712f80b0 | 267 | int |
3eb0018e CR |
268 | execute_array_command (a, v) |
269 | ARRAY *a; | |
712f80b0 CR |
270 | void *v; |
271 | { | |
3eb0018e CR |
272 | char *tag; |
273 | char **argv; | |
274 | int argc, i; | |
712f80b0 CR |
275 | |
276 | tag = (char *)v; | |
3eb0018e CR |
277 | argc = 0; |
278 | argv = array_to_argv (a, &argc); | |
279 | for (i = 0; i < argc; i++) | |
280 | { | |
281 | if (argv[i] && argv[i][0]) | |
282 | execute_variable_command (argv[i], tag); | |
283 | } | |
284 | strvec_dispose (argv); | |
712f80b0 CR |
285 | return 0; |
286 | } | |
287 | #endif | |
288 | ||
d233b485 CR |
289 | static void |
290 | execute_prompt_command () | |
291 | { | |
292 | char *command_to_execute; | |
712f80b0 | 293 | SHELL_VAR *pcv; |
3eb0018e | 294 | #if defined (ARRAY_VARS) |
712f80b0 | 295 | ARRAY *pcmds; |
3eb0018e | 296 | #endif |
712f80b0 | 297 | |
3eb0018e CR |
298 | pcv = find_variable ("PROMPT_COMMAND"); |
299 | if (pcv == 0 || var_isset (pcv) == 0 || invisible_p (pcv)) | |
300 | return; | |
301 | #if defined (ARRAY_VARS) | |
302 | if (array_p (pcv)) | |
712f80b0 | 303 | { |
3eb0018e CR |
304 | if ((pcmds = array_cell (pcv)) && array_num_elements (pcmds) > 0) |
305 | execute_array_command (pcmds, "PROMPT_COMMAND"); | |
712f80b0 CR |
306 | return; |
307 | } | |
3eb0018e CR |
308 | else if (assoc_p (pcv)) |
309 | return; /* currently don't allow associative arrays here */ | |
712f80b0 | 310 | #endif |
d233b485 | 311 | |
3eb0018e | 312 | command_to_execute = value_cell (pcv); |
712f80b0 | 313 | if (command_to_execute && *command_to_execute) |
d233b485 CR |
314 | execute_variable_command (command_to_execute, "PROMPT_COMMAND"); |
315 | } | |
712f80b0 | 316 | |
ccc6cda3 JA |
317 | /* Call the YACC-generated parser and return the status of the parse. |
318 | Input is read from the current input stream (bash_input). yyparse | |
319 | leaves the parsed command in the global variable GLOBAL_COMMAND. | |
320 | This is where PROMPT_COMMAND is executed. */ | |
321 | int | |
322 | parse_command () | |
323 | { | |
324 | int r; | |
ccc6cda3 JA |
325 | |
326 | need_here_doc = 0; | |
327 | run_pending_traps (); | |
328 | ||
329 | /* Allow the execution of a random command just before the printing | |
330 | of each primary prompt. If the shell variable PROMPT_COMMAND | |
3eb0018e | 331 | is set then its value (array or string) is the command(s) to execute. */ |
a0c0a00f CR |
332 | /* The tests are a combination of SHOULD_PROMPT() and prompt_again() |
333 | from parse.y, which are the conditions under which the prompt is | |
334 | actually printed. */ | |
335 | if (interactive && bash_input.type != st_string && parser_expanding_alias() == 0) | |
ccc6cda3 | 336 | { |
712f80b0 CR |
337 | #if defined (READLINE) |
338 | if (no_line_editing || (bash_input.type == st_stdin && parser_will_prompt ())) | |
339 | #endif | |
340 | execute_prompt_command (); | |
ccc6cda3 JA |
341 | |
342 | if (running_under_emacs == 2) | |
343 | send_pwd_to_eterm (); /* Yuck */ | |
344 | } | |
345 | ||
346 | current_command_line_count = 0; | |
347 | r = yyparse (); | |
348 | ||
349 | if (need_here_doc) | |
350 | gather_here_documents (); | |
351 | ||
352 | return (r); | |
353 | } | |
354 | ||
355 | /* Read and parse a command, returning the status of the parse. The command | |
356 | is left in the globval variable GLOBAL_COMMAND for use by reader_loop. | |
357 | This is where the shell timeout code is executed. */ | |
358 | int | |
359 | read_command () | |
360 | { | |
361 | SHELL_VAR *tmout_var; | |
362 | int tmout_len, result; | |
363 | SigHandler *old_alrm; | |
364 | ||
bb70624e | 365 | set_current_prompt_level (1); |
ccc6cda3 JA |
366 | global_command = (COMMAND *)NULL; |
367 | ||
368 | /* Only do timeouts if interactive. */ | |
369 | tmout_var = (SHELL_VAR *)NULL; | |
370 | tmout_len = 0; | |
f73dda09 | 371 | old_alrm = (SigHandler *)NULL; |
ccc6cda3 JA |
372 | |
373 | if (interactive) | |
374 | { | |
375 | tmout_var = find_variable ("TMOUT"); | |
ccc6cda3 | 376 | |
7117c2d2 | 377 | if (tmout_var && var_isset (tmout_var)) |
ccc6cda3 | 378 | { |
7117c2d2 | 379 | tmout_len = atoi (value_cell (tmout_var)); |
ccc6cda3 JA |
380 | if (tmout_len > 0) |
381 | { | |
382 | old_alrm = set_signal_handler (SIGALRM, alrm_catcher); | |
383 | alarm (tmout_len); | |
384 | } | |
385 | } | |
386 | } | |
387 | ||
388 | QUIT; | |
389 | ||
390 | current_command_line_count = 0; | |
391 | result = parse_command (); | |
392 | ||
393 | if (interactive && tmout_var && (tmout_len > 0)) | |
394 | { | |
395 | alarm(0); | |
396 | set_signal_handler (SIGALRM, old_alrm); | |
397 | } | |
398 | ||
399 | return (result); | |
400 | } |