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Commit | Line | Data |
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bb70624e | 1 | /* eval.c -- reading and evaluating commands. */ |
ccc6cda3 | 2 | |
bb70624e | 3 | /* Copyright (C) 1996 Free Software Foundation, Inc. |
ccc6cda3 | 4 | |
bb70624e | 5 | This file is part of GNU Bash, the Bourne Again SHell. |
ccc6cda3 | 6 | |
bb70624e JA |
7 | Bash is free software; you can redistribute it and/or modify it |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
ccc6cda3 | 11 | |
bb70624e JA |
12 | Bash is distributed in the hope that it will be useful, but WITHOUT |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
ccc6cda3 | 16 | |
bb70624e JA |
17 | You should have received a copy of the GNU General Public License |
18 | along with Bash; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ | |
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 | ||
33 | #include "shell.h" | |
34 | #include "flags.h" | |
35 | #include "trap.h" | |
36 | ||
37 | #include "builtins/common.h" | |
38 | ||
39 | #include "input.h" | |
40 | #include "execute_cmd.h" | |
41 | ||
b72432fd JA |
42 | #if defined (HISTORY) |
43 | # include "bashhist.h" | |
44 | #endif | |
45 | ||
ccc6cda3 JA |
46 | extern int yyparse (); |
47 | ||
48 | extern int EOF_reached; | |
49 | extern int indirection_level, interactive, interactive_shell; | |
bb70624e | 50 | extern int posixly_correct; |
ccc6cda3 | 51 | extern int subshell_environment, running_under_emacs; |
d166f048 | 52 | extern int last_command_exit_value, stdin_redir; |
ccc6cda3 JA |
53 | extern int need_here_doc; |
54 | extern int current_command_number, current_command_line_count, line_number; | |
ccc6cda3 JA |
55 | extern int expand_aliases; |
56 | ||
57 | /* Read and execute commands until EOF is reached. This assumes that | |
58 | the input source has already been initialized. */ | |
59 | int | |
60 | reader_loop () | |
61 | { | |
62 | int our_indirection_level; | |
63 | COMMAND *current_command = (COMMAND *)NULL; | |
64 | ||
65 | our_indirection_level = ++indirection_level; | |
66 | ||
67 | while (EOF_Reached == 0) | |
68 | { | |
69 | int code; | |
70 | ||
71 | code = setjmp (top_level); | |
72 | ||
73 | #if defined (PROCESS_SUBSTITUTION) | |
74 | unlink_fifo_list (); | |
75 | #endif /* PROCESS_SUBSTITUTION */ | |
76 | ||
77 | if (interactive_shell && signal_is_ignored (SIGINT) == 0) | |
78 | set_signal_handler (SIGINT, sigint_sighandler); | |
79 | ||
80 | if (code != NOT_JUMPED) | |
81 | { | |
82 | indirection_level = our_indirection_level; | |
83 | ||
84 | switch (code) | |
85 | { | |
86 | /* Some kind of throw to top_level has occured. */ | |
87 | case FORCE_EOF: | |
88 | case EXITPROG: | |
89 | current_command = (COMMAND *)NULL; | |
bb70624e JA |
90 | if (exit_immediately_on_error) |
91 | variable_context = 0; /* not in a function */ | |
ccc6cda3 JA |
92 | EOF_Reached = EOF; |
93 | goto exec_done; | |
94 | ||
95 | case DISCARD: | |
96 | last_command_exit_value = 1; | |
97 | if (subshell_environment) | |
98 | { | |
99 | current_command = (COMMAND *)NULL; | |
100 | EOF_Reached = EOF; | |
101 | goto exec_done; | |
102 | } | |
103 | /* Obstack free command elements, etc. */ | |
104 | if (current_command) | |
105 | { | |
106 | dispose_command (current_command); | |
107 | current_command = (COMMAND *)NULL; | |
108 | } | |
109 | break; | |
110 | ||
111 | default: | |
b72432fd | 112 | command_error ("reader_loop", CMDERR_BADJUMP, code, 0); |
ccc6cda3 JA |
113 | } |
114 | } | |
115 | ||
116 | executing = 0; | |
117 | dispose_used_env_vars (); | |
118 | ||
119 | #if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA) | |
120 | /* Attempt to reclaim memory allocated with alloca (). */ | |
121 | (void) alloca (0); | |
122 | #endif | |
123 | ||
124 | if (read_command () == 0) | |
125 | { | |
126 | if (interactive_shell == 0 && read_but_dont_execute) | |
127 | { | |
128 | last_command_exit_value = EXECUTION_SUCCESS; | |
129 | dispose_command (global_command); | |
130 | global_command = (COMMAND *)NULL; | |
131 | } | |
132 | else if (current_command = global_command) | |
133 | { | |
134 | global_command = (COMMAND *)NULL; | |
135 | current_command_number++; | |
136 | ||
137 | executing = 1; | |
d166f048 | 138 | stdin_redir = 0; |
ccc6cda3 JA |
139 | execute_command (current_command); |
140 | ||
141 | exec_done: | |
142 | if (current_command) | |
28ef6c31 | 143 | { |
ccc6cda3 JA |
144 | dispose_command (current_command); |
145 | current_command = (COMMAND *)NULL; | |
28ef6c31 | 146 | } |
ccc6cda3 JA |
147 | |
148 | QUIT; | |
149 | } | |
150 | } | |
151 | else | |
152 | { | |
153 | /* Parse error, maybe discard rest of stream if not interactive. */ | |
154 | if (interactive == 0) | |
155 | EOF_Reached = EOF; | |
156 | } | |
157 | if (just_one_command) | |
158 | EOF_Reached = EOF; | |
159 | } | |
160 | indirection_level--; | |
161 | return (last_command_exit_value); | |
162 | } | |
163 | ||
164 | static sighandler | |
165 | alrm_catcher(i) | |
166 | int i; | |
167 | { | |
b72432fd | 168 | printf ("\007timed out waiting for input: auto-logout\n"); |
ccc6cda3 JA |
169 | jump_to_top_level (EXITPROG); |
170 | SIGRETURN (0); | |
171 | } | |
172 | ||
173 | /* Send an escape sequence to emacs term mode to tell it the | |
174 | current working directory. */ | |
175 | static void | |
176 | send_pwd_to_eterm () | |
177 | { | |
178 | char *pwd; | |
179 | ||
180 | pwd = get_string_value ("PWD"); | |
181 | if (pwd == 0) | |
182 | pwd = get_working_directory ("eterm"); | |
183 | fprintf (stderr, "\032/%s\n", pwd); | |
184 | } | |
185 | ||
186 | /* Call the YACC-generated parser and return the status of the parse. | |
187 | Input is read from the current input stream (bash_input). yyparse | |
188 | leaves the parsed command in the global variable GLOBAL_COMMAND. | |
189 | This is where PROMPT_COMMAND is executed. */ | |
190 | int | |
191 | parse_command () | |
192 | { | |
193 | int r; | |
194 | char *command_to_execute; | |
195 | ||
196 | need_here_doc = 0; | |
197 | run_pending_traps (); | |
198 | ||
199 | /* Allow the execution of a random command just before the printing | |
200 | of each primary prompt. If the shell variable PROMPT_COMMAND | |
201 | is set then the value of it is the command to execute. */ | |
202 | if (interactive && bash_input.type != st_string) | |
203 | { | |
204 | command_to_execute = get_string_value ("PROMPT_COMMAND"); | |
205 | if (command_to_execute) | |
206 | execute_prompt_command (command_to_execute); | |
207 | ||
208 | if (running_under_emacs == 2) | |
209 | send_pwd_to_eterm (); /* Yuck */ | |
210 | } | |
211 | ||
212 | current_command_line_count = 0; | |
213 | r = yyparse (); | |
214 | ||
215 | if (need_here_doc) | |
216 | gather_here_documents (); | |
217 | ||
218 | return (r); | |
219 | } | |
220 | ||
221 | /* Read and parse a command, returning the status of the parse. The command | |
222 | is left in the globval variable GLOBAL_COMMAND for use by reader_loop. | |
223 | This is where the shell timeout code is executed. */ | |
224 | int | |
225 | read_command () | |
226 | { | |
227 | SHELL_VAR *tmout_var; | |
228 | int tmout_len, result; | |
229 | SigHandler *old_alrm; | |
230 | ||
bb70624e | 231 | set_current_prompt_level (1); |
ccc6cda3 JA |
232 | global_command = (COMMAND *)NULL; |
233 | ||
234 | /* Only do timeouts if interactive. */ | |
235 | tmout_var = (SHELL_VAR *)NULL; | |
236 | tmout_len = 0; | |
237 | ||
238 | if (interactive) | |
239 | { | |
240 | tmout_var = find_variable ("TMOUT"); | |
241 | old_alrm = (SigHandler *)NULL; | |
242 | ||
243 | if (tmout_var && tmout_var->value) | |
244 | { | |
245 | tmout_len = atoi (tmout_var->value); | |
246 | if (tmout_len > 0) | |
247 | { | |
248 | old_alrm = set_signal_handler (SIGALRM, alrm_catcher); | |
249 | alarm (tmout_len); | |
250 | } | |
251 | } | |
252 | } | |
253 | ||
254 | QUIT; | |
255 | ||
256 | current_command_line_count = 0; | |
257 | result = parse_command (); | |
258 | ||
259 | if (interactive && tmout_var && (tmout_len > 0)) | |
260 | { | |
261 | alarm(0); | |
262 | set_signal_handler (SIGALRM, old_alrm); | |
263 | } | |
264 | ||
265 | return (result); | |
266 | } |