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Diffstat (limited to '')
| -rw-r--r-- | builtins/fg_bg.def | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/builtins/fg_bg.def b/builtins/fg_bg.def new file mode 100644 index 0000000..0fb5322 --- /dev/null +++ b/builtins/fg_bg.def @@ -0,0 +1,189 @@ +This file is fg_bg.def, from which is created fg_bg.c. +It implements the builtins "bg" and "fg" in Bash. + +Copyright (C) 1987-2020 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>. + +$PRODUCES fg_bg.c + +$BUILTIN fg +$FUNCTION fg_builtin +$DEPENDS_ON JOB_CONTROL +$SHORT_DOC fg [job_spec] +Move job to the foreground. + +Place the job identified by JOB_SPEC in the foreground, making it the +current job. If JOB_SPEC is not present, the shell's notion of the +current job is used. + +Exit Status: +Status of command placed in foreground, or failure if an error occurs. +$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 "../execute_cmd.h" +#include "../jobs.h" +#include "common.h" +#include "bashgetopt.h" + +#if defined (JOB_CONTROL) +static int fg_bg PARAMS((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; + + CHECK_HELPOPT (list); + + 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 ...] +Move jobs to the background. + +Place the jobs identified by each JOB_SPEC in the background, as if they +had been started with `&'. If JOB_SPEC is not present, the shell's notion +of the current job is used. + +Exit Status: +Returns success unless job control is not enabled or an error occurs. +$END + +#if defined (JOB_CONTROL) +/* How to put a job into the background. */ +int +bg_builtin (list) + WORD_LIST *list; +{ + int r; + + CHECK_HELPOPT (list); + + 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 */ |