1JOBS(P) POSIX Programmer's Manual JOBS(P)
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6 jobs - display status of jobs in the current session
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9 jobs [-l| -p][job_id...]
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12 The jobs utility shall display the status of jobs that were started in
13 the current shell environment; see Shell Execution Environment .
14 When jobs reports the termination status of a job, the shell shall
16 remove its process ID from the list of those "known in the current
17 shell execution environment''; see Asynchronous Lists .
18
20 The jobs utility shall conform to the Base Definitions volume of
21 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
22 The following options shall be supported:
24 -l (The letter ell.) Provide more information about each job
26 listed. This information shall include the job number, current
27 job, process group ID, state, and the command that formed the
28 job.
29 -p Display only the process IDs for the process group leaders of
31 the selected jobs.
32 By default, the jobs utility shall display the status of all stopped
35 jobs, running background jobs and all jobs whose status has changed and
36 have not been reported by the shell.
37
39 The following operand shall be supported:
40 job_id Specifies the jobs for which the status is to be displayed. If
42 no job_id is given, the status information for all jobs shall be
43 displayed. The format of job_id is described in the Base Defini‐
44 tions volume of IEEE Std 1003.1-2001, Section 3.203, Job Control
45 Job ID.
46
49 Not used.
50
52 None.
53
55 The following environment variables shall affect the execution of jobs:
56 LANG Provide a default value for the internationalization variables
58 that are unset or null. (See the Base Definitions volume of
59 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
60 ables for the precedence of internationalization variables used
61 to determine the values of locale categories.)
62 LC_ALL If set to a non-empty string value, override the values of all
64 the other internationalization variables.
65 LC_CTYPE
67 Determine the locale for the interpretation of sequences of
68 bytes of text data as characters (for example, single-byte as
69 opposed to multi-byte characters in arguments).
70 LC_MESSAGES
72 Determine the locale that should be used to affect the format
73 and contents of diagnostic messages written to standard error
74 and informative messages written to standard output.
75 NLSPATH
77 Determine the location of message catalogs for the processing of
78 LC_MESSAGES .
79
82 Default.
83
85 If the -p option is specified, the output shall consist of one line for
86 each process ID:
87 "%d\n", <process ID>
90 Otherwise, if the -l option is not specified, the output shall be a
92 series of lines of the form:
93 "[%d] %c %s %s\n", <job-number>, <current>, <state>, <command>
96 where the fields shall be as follows:
98 <current>
100 The character '+' identifies the job that would be used as a
101 default for the fg or bg utilities; this job can also be speci‐
102 fied using the job_id %+ or "%%" . The character '-' identifies
103 the job that would become the default if the current default job
104 were to exit; this job can also be specified using the job_id
105 %-. For other jobs, this field is a <space>. At most one job can
106 be identified with '+' and at most one job can be identified
107 with '-' . If there is any suspended job, then the current job
108 shall be a suspended job. If there are at least two suspended
109 jobs, then the previous job also shall be a suspended job.
110 <job-number>
112 A number that can be used to identify the process group to the
113 wait, fg, bg, and kill utilities. Using these utilities, the job
114 can be identified by prefixing the job number with '%' .
115 <state>
117 One of the following strings (in the POSIX locale):
118 Running
120 Indicates that the job has not been suspended by a signal and
121 has not exited.
122 Done
124 Indicates that the job completed and returned exit status zero.
125 Done(code)
127 Indicates that the job completed normally and that it exited
128 with the specified non-zero exit status, code, expressed as a
129 decimal number.
130 Stopped
132 Indicates that the job was suspended by the SIGTSTP signal.
133 Stopped (SIGTSTP)
135 Indicates that the job was suspended by the SIGTSTP signal.
137 Stopped (SIGSTOP)
139 Indicates that the job was suspended by the SIGSTOP signal.
141 Stopped (SIGTTIN)
143 Indicates that the job was suspended by the SIGTTIN signal.
145 Stopped (SIGTTOU)
147 Indicates that the job was suspended by the SIGTTOU signal.
149 The implementation may substitute the string Suspended in place of
152 Stopped. If the job was terminated by a signal, the format of <state>
153 is unspecified, but it shall be visibly distinct from all of the other
154 <state> formats shown here and shall indicate the name or description
155 of the signal causing the termination.
156 <command>
158 The associated command that was given to the shell.
159 If the -l option is specified, a field containing the process group ID
162 shall be inserted before the <state> field. Also, more processes in a
163 process group may be output on separate lines, using only the process
164 ID and <command> fields.
165
167 The standard error shall be used only for diagnostic messages.
168
170 None.
171
173 None.
174
176 The following exit values shall be returned:
177 0 Successful completion.
179 >0 An error occurred.
181
184 Default.
185 The following sections are informative.
187
189 The -p option is the only portable way to find out the process group of
190 a job because different implementations have different strategies for
191 defining the process group of the job. Usage such as $( jobs -p) pro‐
192 vides a way of referring to the process group of the job in an imple‐
193 mentation-independent way.
194 The jobs utility does not work as expected when it is operating in its
196 own utility execution environment because that environment has no
197 applicable jobs to manipulate. See the APPLICATION USAGE section for bg
198 . For this reason, jobs is generally implemented as a shell regular
199 built-in.
200
202 None.
203
205 Both "%%" and "%+" are used to refer to the current job. Both forms
206 are of equal validity-the "%%" mirroring "$$" and "%+" mirroring the
207 output of jobs. Both forms reflect historical practice of the Korn‐
208 Shell and the C shell with job control.
209 The job control features provided by bg, fg, and jobs are based on the
211 KornShell. The standard developers examined the characteristics of the
212 C shell versions of these utilities and found that differences exist.
213 Despite widespread use of the C shell, the KornShell versions were
214 selected for this volume of IEEE Std 1003.1-2001 to maintain a degree
215 of uniformity with the rest of the KornShell features selected (such as
216 the very popular command line editing features).
217 The jobs utility is not dependent on the job control option, as are the
219 seemingly related bg and fg utilities because jobs is useful for exam‐
220 ining background jobs, regardless of the condition of job control.
221 When the user has invoked a set +m command and job control has been
222 turned off, jobs can still be used to examine the background jobs asso‐
223 ciated with that current session. Similarly, kill can then be used to
224 kill background jobs with kill% <background job number>.
225 The output for terminated jobs is left unspecified to accommodate vari‐
227 ous historical systems. The following formats have been witnessed:
228 1. Killed( signal name)
230 2. signal name
232 3. signal name( coredump)
234 4. signal description- core dumped
236 Most users should be able to understand these formats, although it
238 means that applications have trouble parsing them.
239 The calculation of job IDs was not described since this would suggest
241 an implementation, which may impose unnecessary restrictions.
242 In an early proposal, a -n option was included to "Display the status
244 of jobs that have changed, exited, or stopped since the last status
245 report". It was removed because the shell always writes any changed
246 status of jobs before each prompt.
247
249 None.
250
252 Shell Execution Environment , bg , fg , kill() , wait()
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255 Portions of this text are reprinted and reproduced in electronic form
256 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
257 -- Portable Operating System Interface (POSIX), The Open Group Base
258 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
259 Electrical and Electronics Engineers, Inc and The Open Group. In the
260 event of any discrepancy between this version and the original IEEE and
261 The Open Group Standard, the original IEEE and The Open Group Standard
262 is the referee document. The original Standard can be obtained online
263 at http://www.opengroup.org/unix/online.html .
264IEEE/The Open Group 2003 JOBS(P)