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PROLOG

       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

       jobs — display status of jobs in the current session

SYNOPSIS

       jobs [−l|−p] [job_id...]

DESCRIPTION

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

       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 2.9.3.1, Examples.

OPTIONS

       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

       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

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of jobs:

       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
                 categories.)

       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).

       LC_MESSAGES
                 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 output.

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

ASYNCHRONOUS EVENTS

       Default.

STDOUT

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.

<job-number>
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.

Done(code)
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

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       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.
       For this reason, jobs is generally implemented as a shell regular built-in.

EXAMPLES

       None.

RATIONALE

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 witnessed:

1. Killed(signal name)

2. signal name

3. signal name(coredump)

4. signal description− core 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.

FUTURE DIRECTIONS

       None.

COPYRIGHT

       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
       http://www.unix.org/online.html .

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