1 /* eval.c -- reading and evaluating commands. */
3 /* Copyright (C) 1996 Free Software Foundation, Inc.
5 This file is part of GNU Bash, the Bourne Again SHell.
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)
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.
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. */
23 #if defined (HAVE_UNISTD_H)
25 # include <sys/types.h>
37 #include "builtins/common.h"
40 #include "execute_cmd.h"
43 # include "bashhist.h"
46 extern int yyparse ();
48 extern int EOF_reached;
49 extern int indirection_level, interactive, interactive_shell;
50 extern int posixly_correct;
51 extern int subshell_environment, running_under_emacs;
52 extern int last_command_exit_value, stdin_redir;
53 extern int need_here_doc;
54 extern int current_command_number, current_command_line_count, line_number;
55 extern int expand_aliases;
57 /* Read and execute commands until EOF is reached. This assumes that
58 the input source has already been initialized. */
62 int our_indirection_level;
63 COMMAND *current_command = (COMMAND *)NULL;
65 our_indirection_level = ++indirection_level;
67 while (EOF_Reached == 0)
71 code = setjmp (top_level);
73 #if defined (PROCESS_SUBSTITUTION)
75 #endif /* PROCESS_SUBSTITUTION */
77 if (interactive_shell && signal_is_ignored (SIGINT) == 0)
78 set_signal_handler (SIGINT, sigint_sighandler);
80 if (code != NOT_JUMPED)
82 indirection_level = our_indirection_level;
86 /* Some kind of throw to top_level has occured. */
89 current_command = (COMMAND *)NULL;
90 if (exit_immediately_on_error)
91 variable_context = 0; /* not in a function */
96 last_command_exit_value = 1;
97 if (subshell_environment)
99 current_command = (COMMAND *)NULL;
103 /* Obstack free command elements, etc. */
106 dispose_command (current_command);
107 current_command = (COMMAND *)NULL;
112 command_error ("reader_loop", CMDERR_BADJUMP, code, 0);
117 dispose_used_env_vars ();
119 #if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA)
120 /* Attempt to reclaim memory allocated with alloca (). */
124 if (read_command () == 0)
126 if (interactive_shell == 0 && read_but_dont_execute)
128 last_command_exit_value = EXECUTION_SUCCESS;
129 dispose_command (global_command);
130 global_command = (COMMAND *)NULL;
132 else if (current_command = global_command)
134 global_command = (COMMAND *)NULL;
135 current_command_number++;
139 execute_command (current_command);
144 dispose_command (current_command);
145 current_command = (COMMAND *)NULL;
153 /* Parse error, maybe discard rest of stream if not interactive. */
154 if (interactive == 0)
157 if (just_one_command)
161 return (last_command_exit_value);
168 printf ("\007timed out waiting for input: auto-logout\n");
169 jump_to_top_level (EXITPROG);
173 /* Send an escape sequence to emacs term mode to tell it the
174 current working directory. */
180 pwd = get_string_value ("PWD");
182 pwd = get_working_directory ("eterm");
183 fprintf (stderr, "\032/%s\n", pwd);
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. */
194 char *command_to_execute;
197 run_pending_traps ();
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)
204 command_to_execute = get_string_value ("PROMPT_COMMAND");
205 if (command_to_execute)
206 execute_prompt_command (command_to_execute);
208 if (running_under_emacs == 2)
209 send_pwd_to_eterm (); /* Yuck */
212 current_command_line_count = 0;
216 gather_here_documents ();
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. */
227 SHELL_VAR *tmout_var;
228 int tmout_len, result;
229 SigHandler *old_alrm;
231 set_current_prompt_level (1);
232 global_command = (COMMAND *)NULL;
234 /* Only do timeouts if interactive. */
235 tmout_var = (SHELL_VAR *)NULL;
240 tmout_var = find_variable ("TMOUT");
241 old_alrm = (SigHandler *)NULL;
243 if (tmout_var && tmout_var->value)
245 tmout_len = atoi (tmout_var->value);
248 old_alrm = set_signal_handler (SIGALRM, alrm_catcher);
256 current_command_line_count = 0;
257 result = parse_command ();
259 if (interactive && tmout_var && (tmout_len > 0))
262 set_signal_handler (SIGALRM, old_alrm);