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
13 jobs — display status of jobs in the current session
14
16 jobs [−l|−p] [job_id...]
17
19 The jobs utility shall display the status of jobs that were started in
20 the current shell environment; see Section 2.12, Shell Execution Envi‐
21 ronment.
22 When jobs reports the termination status of a job, the shell shall
24 remove its process ID from the list of those ``known in the current
25 shell execution environment''; see Section 2.9.3.1, Examples.
26
28 The jobs utility shall conform to the Base Definitions volume of
29 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
30 The following options shall be supported:
32 −l (The letter ell.) Provide more information about each job
34 listed. This information shall include the job number, cur‐
35 rent job, process group ID, state, and the command that
36 formed the job.
37 −p Display only the process IDs for the process group leaders of
39 the selected jobs.
40 By default, the jobs utility shall display the status of all stopped
42 jobs, running background jobs and all jobs whose status has changed and
43 have not been reported by the shell.
44
46 The following operand shall be supported:
47 job_id Specifies the jobs for which the status is to be displayed.
49 If no job_id is given, the status information for all jobs
50 shall be displayed. The format of job_id is described in the
51 Base Definitions volume of POSIX.1‐2008, Section 3.204, Job
52 Control Job ID.
53
55 Not used.
56
58 None.
59
61 The following environment variables shall affect the execution of jobs:
62 LANG Provide a default value for the internationalization vari‐
64 ables that are unset or null. (See the Base Definitions vol‐
65 ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
66 ables for the precedence of internationalization variables
67 used to determine the values of locale categories.)
68 LC_ALL If set to a non-empty string value, override the values of
70 all the other internationalization variables.
71 LC_CTYPE Determine the locale for the interpretation of sequences of
73 bytes of text data as characters (for example, single-byte as
74 opposed to multi-byte characters in arguments).
75 LC_MESSAGES
77 Determine the locale that should be used to affect the format
78 and contents of diagnostic messages written to standard error
79 and informative messages written to standard output.
80 NLSPATH Determine the location of message catalogs for the processing
82 of LC_MESSAGES.
83
85 Default.
86
88 If the −p option is specified, the output shall consist of one line for
89 each process ID:
90 "%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>
97 where the fields shall be as follows:
99 <current> The character '+' identifies the job that would be used as a
101 default for the fg or bg utilities; this job can also be
102 specified using the job_id %+ or "%%". The character '−'
103 identifies the job that would become the default if the cur‐
104 rent default job were to exit; this job can also be specified
105 using the job_id %−. For other jobs, this field is a <space>.
106 At most one job can be identified with '+' and at most one
107 job can be identified with '−'. If there is any suspended
108 job, then the current job shall be a suspended job. If there
109 are at least two suspended jobs, then the previous job also
110 shall be a suspended job.
111 <job-number>
113 A number that can be used to identify the process group to
114 the wait, fg, bg, and kill utilities. Using these utilities,
115 the job can be identified by prefixing the job number with
116 '%'.
117 <state> One of the following strings (in the POSIX locale):
119 Running Indicates that the job has not been suspended by a
121 signal and has not exited.
122 Done Indicates that the job completed and returned exit
124 status zero.
125 Done(code)
127 Indicates that the job completed normally and that
128 it exited with the specified non-zero exit status,
129 code, expressed as a decimal number.
130 Stopped Indicates that the job was suspended by the SIGTSTP
132 signal.
133 Stopped (SIGTSTP)
135 Indicates that the job was suspended by the SIGTSTP
136 signal.
137 Stopped (SIGSTOP)
139 Indicates that the job was suspended by the SIGSTOP
140 signal.
141 Stopped (SIGTTIN)
143 Indicates that the job was suspended by the SIGTTIN
144 signal.
145 Stopped (SIGTTOU)
147 Indicates that the job was suspended by the SIGTTOU
148 signal.
149 The implementation may substitute the string Suspended in
151 place of Stopped. If the job was terminated by a signal, the
152 format of <state> is unspecified, but it shall be visibly
153 distinct from all of the other <state> formats shown here and
154 shall indicate the name or description of the signal causing
155 the termination.
156 <command> The associated command that was given to the shell.
158 If the −l option is specified, a field containing the process group ID
160 shall be inserted before the <state> field. Also, more processes in a
161 process group may be output on separate lines, using only the process
162 ID and <command> fields.
163
165 The standard error shall be used only for diagnostic messages.
166
168 None.
169
171 None.
172
174 The following exit values shall be returned:
175 0 Successful completion.
177 >0 An error occurred.
179
181 Default.
182 The following sections are informative.
184
186 The −p option is the only portable way to find out the process group of
187 a job because different implementations have different strategies for
188 defining the process group of the job. Usage such as $(jobs −p) pro‐
189 vides a way of referring to the process group of the job in an imple‐
190 mentation-independent way.
191 The jobs utility does not work as expected when it is operating in its
193 own utility execution environment because that environment has no
194 applicable jobs to manipulate. See the APPLICATION USAGE section for
195 bg. For this reason, jobs is generally implemented as a shell regular
196 built-in.
197
199 None.
200
202 Both "%%" and "%+" are used to refer to the current job. Both forms are
203 of equal validity—the "%%" mirroring "$$" and "%+" mirroring the output
204 of jobs. Both forms reflect historical practice of the KornShell and
205 the C shell with job control.
206 The job control features provided by bg, fg, and jobs are based on the
208 KornShell. The standard developers examined the characteristics of the
209 C shell versions of these utilities and found that differences exist.
210 Despite widespread use of the C shell, the KornShell versions were
211 selected for this volume of POSIX.1‐2008 to maintain a degree of uni‐
212 formity with the rest of the KornShell features selected (such as the
213 very popular command line editing features).
214 The jobs utility is not dependent on the job control option, as are the
216 seemingly related bg and fg utilities because jobs is useful for exam‐
217 ining background jobs, regardless of the condition of job control. When
218 the user has invoked a set +m command and job control has been turned
219 off, jobs can still be used to examine the background jobs associated
220 with that current session. Similarly, kill can then be used to kill
221 background jobs with kill %<background job number>.
222 The output for terminated jobs is left unspecified to accommodate vari‐
224 ous historical systems. The following formats have been witnessed:
225 1. Killed(signal name)
227 2. signal name
229 3. signal name(coredump)
231 4. signal description− core dumped
233 Most users should be able to understand these formats, although it
235 means that applications have trouble parsing them.
236 The calculation of job IDs was not described since this would suggest
238 an implementation, which may impose unnecessary restrictions.
239 In an early proposal, a −n option was included to ``Display the status
241 of jobs that have changed, exited, or stopped since the last status
242 report''. It was removed because the shell always writes any changed
243 status of jobs before each prompt.
244
246 None.
247
249 Section 2.12, Shell Execution Environment, bg, fg, kill, wait
250 The Base Definitions volume of POSIX.1‐2008, Section 3.204, Job Control
252 Job ID, Chapter 8, Environment Variables, Section 12.2, Utility Syntax
253 Guidelines
254
256 Portions of this text are reprinted and reproduced in electronic form
257 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
258 -- Portable Operating System Interface (POSIX), The Open Group Base
259 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
260 cal and Electronics Engineers, Inc and The Open Group. (This is
261 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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 2013 JOBS(1P)