1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
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 */
|
