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



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult 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 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 Asynchronous Lists .

OPTIONS
       The  jobs  utility  shall  conform  to  the Base Definitions volume of IEEE Std 1003.1-2001, 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 IEEE Std 1003.1-2001,
              Section 3.203, 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  IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of international-
              ization 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 stan-
              dard 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 util-
              ities, 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 dif-
       ferent 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 con-
       trol.

       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 IEEE Std 1003.1-2001 to maintain a degree of unifor-
       mity 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.

SEE ALSO
       Shell Execution Environment, bg, fg, kill(), wait()

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                      JOBS(1P)