1JOBS(1P) POSIX Programmer's Manual JOBS(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 jobs — display status of jobs in the current session
13
15 jobs [-l|-p] [job_id...]
16
18 The jobs utility shall display the status of jobs that were started in
19 the current shell environment; see Section 2.12, Shell Execution Envi‐
20 ronment.
21 When jobs reports the termination status of a job, the shell shall
23 remove its process ID from the list of those ``known in the current
24 shell execution environment''; see Section 2.9.3.1, Examples.
25
27 The jobs utility shall conform to the Base Definitions volume of
28 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
29 The following options shall be supported:
31 -l (The letter ell.) Provide more information about each job
33 listed. This information shall include the job number, cur‐
34 rent job, process group ID, state, and the command that
35 formed the job.
36 -p Display only the process IDs for the process group leaders of
38 the selected jobs.
39 By default, the jobs utility shall display the status of all stopped
41 jobs, running background jobs and all jobs whose status has changed and
42 have not been reported by the shell.
43
45 The following operand shall be supported:
46 job_id Specifies the jobs for which the status is to be displayed.
48 If no job_id is given, the status information for all jobs
49 shall be displayed. The format of job_id is described in the
50 Base Definitions volume of POSIX.1‐2017, Section 3.204, Job
51 Control Job ID.
52
54 Not used.
55
57 None.
58
60 The following environment variables shall affect the execution of jobs:
61 LANG Provide a default value for the internationalization vari‐
63 ables that are unset or null. (See the Base Definitions vol‐
64 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
65 ables for the precedence of internationalization variables
66 used to determine the values of locale categories.)
67 LC_ALL If set to a non-empty string value, override the values of
69 all the other internationalization variables.
70 LC_CTYPE Determine the locale for the interpretation of sequences of
72 bytes of text data as characters (for example, single-byte as
73 opposed to multi-byte characters in arguments).
74 LC_MESSAGES
76 Determine the locale that should be used to affect the format
77 and contents of diagnostic messages written to standard error
78 and informative messages written to standard output.
79 NLSPATH Determine the location of message catalogs for the processing
81 of LC_MESSAGES.
82
84 Default.
85
87 If the -p option is specified, the output shall consist of one line for
88 each process ID:
89 "%d\n", <process ID>
92 Otherwise, if the -l option is not specified, the output shall be a
94 series of lines of the form:
95 "[%d] %c %s %s\n", <job-number>, <current>, <state>, <command>
98 where the fields shall be as follows:
100 <current> The character '+' identifies the job that would be used as a
102 default for the fg or bg utilities; this job can also be
103 specified using the job_id %+ or "%%". The character '-'
104 identifies the job that would become the default if the cur‐
105 rent default job were to exit; this job can also be specified
106 using the job_id %-. For other jobs, this field is a <space>.
107 At most one job can be identified with '+' and at most one
108 job can be identified with '-'. If there is any suspended
109 job, then the current job shall be a suspended job. If there
110 are at least two suspended jobs, then the previous job also
111 shall be a suspended job.
112 <job-number>
114 A number that can be used to identify the process group to
115 the wait, fg, bg, and kill utilities. Using these utilities,
116 the job can be identified by prefixing the job number with
117 '%'.
118 <state> One of the following strings (in the POSIX locale):
120 Running Indicates that the job has not been suspended by a
122 signal and has not exited.
123 Done Indicates that the job completed and returned exit
125 status zero.
126 Done(code)
128 Indicates that the job completed normally and that
129 it exited with the specified non-zero exit status,
130 code, expressed as a decimal number.
131 Stopped Indicates that the job was suspended by the SIGTSTP
133 signal.
134 Stopped (SIGTSTP)
136 Indicates that the job was suspended by the SIGTSTP
137 signal.
138 Stopped (SIGSTOP)
140 Indicates that the job was suspended by the SIGSTOP
141 signal.
142 Stopped (SIGTTIN)
144 Indicates that the job was suspended by the SIGTTIN
145 signal.
146 Stopped (SIGTTOU)
148 Indicates that the job was suspended by the SIGTTOU
149 signal.
150 The implementation may substitute the string Suspended in
152 place of Stopped. If the job was terminated by a signal, the
153 format of <state> is unspecified, but it shall be visibly
154 distinct from all of the other <state> formats shown here and
155 shall indicate the name or description of the signal causing
156 the termination.
157 <command> The associated command that was given to the shell.
159 If the -l option is specified, a field containing the process group ID
161 shall be inserted before the <state> field. Also, more processes in a
162 process group may be output on separate lines, using only the process
163 ID and <command> fields.
164
166 The standard error shall be used only for diagnostic messages.
167
169 None.
170
172 None.
173
175 The following exit values shall be returned:
176 0 Successful completion.
178 >0 An error occurred.
180
182 Default.
183 The following sections are informative.
185
187 The -p option is the only portable way to find out the process group of
188 a job because different implementations have different strategies for
189 defining the process group of the job. Usage such as $(jobs -p) pro‐
190 vides a way of referring to the process group of the job in an imple‐
191 mentation-independent way.
192 The jobs utility does not work as expected when it is operating in its
194 own utility execution environment because that environment has no
195 applicable jobs to manipulate. See the APPLICATION USAGE section for
196 bg. For this reason, jobs is generally implemented as a shell regular
197 built-in.
198
200 None.
201
203 Both "%%" and "%+" are used to refer to the current job. Both forms are
204 of equal validity—the "%%" mirroring "$$" and "%+" mirroring the output
205 of jobs. Both forms reflect historical practice of the KornShell and
206 the C shell with job control.
207 The job control features provided by bg, fg, and jobs are based on the
209 KornShell. The standard developers examined the characteristics of the
210 C shell versions of these utilities and found that differences exist.
211 Despite widespread use of the C shell, the KornShell versions were
212 selected for this volume of POSIX.1‐2017 to maintain a degree of uni‐
213 formity with the rest of the KornShell features selected (such as the
214 very popular command line editing features).
215 The jobs utility is not dependent on the job control option, as are the
217 seemingly related bg and fg utilities because jobs is useful for exam‐
218 ining background jobs, regardless of the condition of job control. When
219 the user has invoked a set +m command and job control has been turned
220 off, jobs can still be used to examine the background jobs associated
221 with that current session. Similarly, kill can then be used to kill
222 background jobs with kill %<background job number>.
223 The output for terminated jobs is left unspecified to accommodate vari‐
225 ous historical systems. The following formats have been witnessed:
226 1. Killed(signal name)
228 2. signal name
230 3. signal name(coredump)
232 4. signal description- core dumped
234 Most users should be able to understand these formats, although it
236 means that applications have trouble parsing them.
237 The calculation of job IDs was not described since this would suggest
239 an implementation, which may impose unnecessary restrictions.
240 In an early proposal, a -n option was included to ``Display the status
242 of jobs that have changed, exited, or stopped since the last status
243 report''. It was removed because the shell always writes any changed
244 status of jobs before each prompt.
245
247 None.
248
250 Section 2.12, Shell Execution Environment, bg, fg, kill, wait
251 The Base Definitions volume of POSIX.1‐2017, Section 3.204, Job Control
253 Job ID, Chapter 8, Environment Variables, Section 12.2, Utility Syntax
254 Guidelines
255
257 Portions of this text are reprinted and reproduced in electronic form
258 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
259 table Operating System Interface (POSIX), The Open Group Base Specifi‐
260 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
261 Electrical and Electronics Engineers, Inc and The Open Group. In the
262 event of any discrepancy between this version and the original IEEE and
263 The Open Group Standard, the original IEEE and The Open Group Standard
264 is the referee document. The original Standard can be obtained online
265 at http://www.opengroup.org/unix/online.html .
266 Any typographical or formatting errors that appear in this page are
268 most likely to have been introduced during the conversion of the source
269 files to man page format. To report such errors, see https://www.ker‐
270 nel.org/doc/man-pages/reporting_bugs.html .
271IEEE/The Open Group 2017 JOBS(1P)