jobs(1p) — Linux manual page


JOBS(1P)                  POSIX Programmer's Manual                 JOBS(1P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       jobs — display status of jobs in the current session

SYNOPSIS         top

       jobs [−l|−p] [job_id...]

DESCRIPTION         top

       The jobs utility shall display the status of jobs that were started
       in the current shell environment; see Section 2.12, Shell Execution

       When jobs reports the termination status of a job, the shell shall
       remove its process ID from the list of those ``known in the current
       shell execution environment''; see Section, Examples.

OPTIONS         top

       The jobs utility shall conform to the Base Definitions volume of
       POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       −l        (The letter ell.) Provide more information about each job
                 listed. This information shall include the job number,
                 current job, process group ID, state, and the command that
                 formed the job.

       −p        Display only the process IDs for the process group leaders
                 of the selected jobs.

       By default, the jobs utility shall display the status of all stopped
       jobs, running background jobs and all jobs whose status has changed
       and have not been reported by the shell.

OPERANDS         top

       The following operand shall be supported:

       job_id    Specifies the jobs for which the status is to be displayed.
                 If no job_id is given, the status information for all jobs
                 shall be displayed. The format of job_id is described in
                 the Base Definitions volume of POSIX.1‐2008, Section 3.204,
                 Job Control Job ID.

STDIN         top

       Not used.

INPUT FILES         top



       The following environment variables shall affect the execution of

       LANG      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base Definitions
                 volume of POSIX.1‐2008, Section 8.2, Internationalization
                 Variables for the precedence of internationalization
                 variables used to determine the values of locale

       LC_ALL    If set to a non-empty string value, override the values of
                 all the other internationalization variables.

       LC_CTYPE  Determine the locale for the interpretation of sequences of
                 bytes of text data as characters (for example, single-byte
                 as opposed to multi-byte characters in arguments).

                 Determine the locale that should be used to affect the
                 format and contents of diagnostic messages written to
                 standard error and informative messages written to standard

       NLSPATH   Determine the location of message catalogs for the
                 processing of LC_MESSAGES.



STDOUT         top

       If the −p option is specified, the output shall consist of one line
       for each process ID:

           "%d\n", <process ID>

       Otherwise, if the −l option is not specified, the output shall be a
       series of lines of the form:

           "[%d] %c %s %s\n", <job-number>, <current>, <state>, <command>

       where the fields shall be as follows:

       <current> The character '+' identifies the job that would be used as
                 a default for the fg or bg utilities; this job can also be
                 specified using the job_id %+ or "%%".  The character '−'
                 identifies the job that would become the default if the
                 current default job were to exit; this job can also be
                 specified using the job_id %−. For other jobs, this field
                 is a <space>.  At most one job can be identified with '+'
                 and at most one job can be identified with '−'.  If there
                 is any suspended job, then the current job shall be a
                 suspended job. If there are at least two suspended jobs,
                 then the previous job also shall be a suspended job.

                 A number that can be used to identify the process group to
                 the wait, fg, bg, and kill utilities. Using these
                 utilities, the job can be identified by prefixing the job
                 number with '%'.

       <state>   One of the following strings (in the POSIX locale):

                 Running   Indicates that the job has not been suspended by
                           a signal and has not exited.

                 Done      Indicates that the job completed and returned
                           exit status zero.

                           Indicates that the job completed normally and
                           that it exited with the specified non-zero exit
                           status, code, expressed as a decimal number.

                 Stopped   Indicates that the job was suspended by the
                           SIGTSTP signal.

                 Stopped (SIGTSTP)
                           Indicates that the job was suspended by the
                           SIGTSTP signal.

                 Stopped (SIGSTOP)
                           Indicates that the job was suspended by the
                           SIGSTOP signal.

                 Stopped (SIGTTIN)
                           Indicates that the job was suspended by the
                           SIGTTIN signal.

                 Stopped (SIGTTOU)
                           Indicates that the job was suspended by the
                           SIGTTOU signal.

                 The implementation may substitute the string Suspended in
                 place of Stopped.  If the job was terminated by a signal,
                 the format of <state> is unspecified, but it shall be
                 visibly distinct from all of the other <state> formats
                 shown here and shall indicate the name or description of
                 the signal causing the termination.

       <command> The associated command that was given to the shell.

       If the −l option is specified, a field containing the process group
       ID shall be inserted before the <state> field. Also, more processes
       in a process group may be output on separate lines, using only the
       process ID and <command> fields.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top




EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       The following sections are informative.


       The −p option is the only portable way to find out the process group
       of a job because different implementations have different strategies
       for defining the process group of the job. Usage such as $(jobs −p)
       provides a way of referring to the process group of the job in an
       implementation-independent way.

       The jobs utility does not work as expected when it is operating in
       its own utility execution environment because that environment has no
       applicable jobs to manipulate. See the APPLICATION USAGE section for
       bg(1p).  For this reason, jobs is generally implemented as a shell
       regular built-in.

EXAMPLES         top


RATIONALE         top

       Both "%%" and "%+" are used to refer to the current job. Both forms
       are of equal validity—the "%%" mirroring "$$" and "%+" mirroring the
       output of jobs.  Both forms reflect historical practice of the
       KornShell and the C shell with job control.

       The job control features provided by bg, fg, and jobs are based on
       the KornShell. The standard developers examined the characteristics
       of the C shell versions of these utilities and found that differences
       exist. Despite widespread use of the C shell, the KornShell versions
       were selected for this volume of POSIX.1‐2008 to maintain a degree of
       uniformity with the rest of the KornShell features selected (such as
       the very popular command line editing features).

       The jobs utility is not dependent on the job control option, as are
       the seemingly related bg and fg utilities because jobs is useful for
       examining background jobs, regardless of the condition of job
       control. When the user has invoked a set +m command and job control
       has been turned off, jobs can still be used to examine the background
       jobs associated with that current session. Similarly, kill can then
       be used to kill background jobs with kill %<background job number>.

       The output for terminated jobs is left unspecified to accommodate
       various historical systems. The following formats have been

        1. Killed(signal name)

        2. signal name

        3. signal name(coredump)

        4. signal descriptioncore dumped

       Most users should be able to understand these formats, although it
       means that applications have trouble parsing them.

       The calculation of job IDs was not described since this would suggest
       an implementation, which may impose unnecessary restrictions.

       In an early proposal, a −n option was included to ``Display the
       status of jobs that have changed, exited, or stopped since the last
       status report''. It was removed because the shell always writes any
       changed status of jobs before each prompt.



SEE ALSO         top

       Section 2.12, Shell Execution Environment, bg(1p), fg(1p), kill(1p),

       The Base Definitions volume of POSIX.1‐2008, Section 3.204, Job
       Control Job ID, Chapter 8, Environment Variables, Section 12.2,
       Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see .

IEEE/The Open Group                 2013                            JOBS(1P)

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