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
);