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Diffstat (limited to 'builtins/fg_bg.def')
| -rw-r--r-- | builtins/fg_bg.def | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/builtins/fg_bg.def b/builtins/fg_bg.def new file mode 100644 index 0000000..c14381b --- /dev/null +++ b/builtins/fg_bg.def @@ -0,0 +1,177 @@ +This file is fg_bg.def, from which is created fg_bg.c. +It implements the builtins "bg" and "fg" in Bash. + +Copyright (C) 1987-2005 Free Software Foundation, Inc. + +This file is part of GNU Bash, the Bourne Again SHell. + +Bash is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +Bash is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License along +with Bash; see the file COPYING. If not, write to the Free Software +Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. + +$PRODUCES fg_bg.c + +$BUILTIN fg +$FUNCTION fg_builtin +$DEPENDS_ON JOB_CONTROL +$SHORT_DOC fg [job_spec] +Place JOB_SPEC in the foreground, and make it the current job. If +JOB_SPEC is not present, the shell's notion of the current job is +used. +$END + +#include <config.h> + +#include "../bashtypes.h" +#include <signal.h> + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "../bashintl.h" + +#include "../shell.h" +#include "../jobs.h" +#include "common.h" +#include "bashgetopt.h" + +#if defined (JOB_CONTROL) +extern char *this_command_name; + +static int fg_bg __P((WORD_LIST *, int)); + +/* How to bring a job into the foreground. */ +int +fg_builtin (list) + WORD_LIST *list; +{ + int fg_bit; + register WORD_LIST *t; + + if (job_control == 0) + { + sh_nojobs ((char *)NULL); + return (EXECUTION_FAILURE); + } + + if (no_options (list)) + return (EX_USAGE); + list = loptend; + + /* If the last arg on the line is '&', then start this job in the + background. Else, fg the job. */ + for (t = list; t && t->next; t = t->next) + ; + fg_bit = (t && t->word->word[0] == '&' && t->word->word[1] == '\0') == 0; + + return (fg_bg (list, fg_bit)); +} +#endif /* JOB_CONTROL */ + +$BUILTIN bg +$FUNCTION bg_builtin +$DEPENDS_ON JOB_CONTROL +$SHORT_DOC bg [job_spec ...] +Place each JOB_SPEC in the background, as if it had been started with +`&'. If JOB_SPEC is not present, the shell's notion of the current +job is used. +$END + +#if defined (JOB_CONTROL) +/* How to put a job into the background. */ +int +bg_builtin (list) + WORD_LIST *list; +{ + int r; + + if (job_control == 0) + { + sh_nojobs ((char *)NULL); + return (EXECUTION_FAILURE); + } + + if (no_options (list)) + return (EX_USAGE); + list = loptend; + + /* This relies on the fact that fg_bg() takes a WORD_LIST *, but only acts + on the first member (if any) of that list. */ + r = EXECUTION_SUCCESS; + do + { + if (fg_bg (list, 0) == EXECUTION_FAILURE) + r = EXECUTION_FAILURE; + if (list) + list = list->next; + } + while (list); + + return r; +} + +/* How to put a job into the foreground/background. */ +static int +fg_bg (list, foreground) + WORD_LIST *list; + int foreground; +{ + sigset_t set, oset; + int job, status, old_async_pid; + JOB *j; + + BLOCK_CHILD (set, oset); + job = get_job_spec (list); + + if (INVALID_JOB (job)) + { + if (job != DUP_JOB) + sh_badjob (list ? list->word->word : "current"); + + goto failure; + } + + j = get_job_by_jid (job); + /* Or if j->pgrp == shell_pgrp. */ + if (IS_JOBCONTROL (job) == 0) + { + builtin_error (_("job %d started without job control"), job + 1); + goto failure; + } + + if (foreground == 0) + { + old_async_pid = last_asynchronous_pid; + last_asynchronous_pid = j->pgrp; /* As per Posix.2 5.4.2 */ + } + + status = start_job (job, foreground); + + if (status >= 0) + { + /* win: */ + UNBLOCK_CHILD (oset); + return (foreground ? status : EXECUTION_SUCCESS); + } + else + { + if (foreground == 0) + last_asynchronous_pid = old_async_pid; + + failure: + UNBLOCK_CHILD (oset); + return (EXECUTION_FAILURE); + } +} +#endif /* JOB_CONTROL */ |