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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 dif-
       fer (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 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  informa-
              tion  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 prece-
              dence 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 exam-
              ple, 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  writ-
              ten 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 sig-
       nal, the format of <state> is unspecified, but it shall be visibly distinct from all of the other <state>  for-
       mats 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 exam-
       ined 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 uniformity with the rest of the KornShell features selected (such as the very popular com-
       mand 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, Stan-
       dard  for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifica-
       tions Issue 6, Copyright (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 Stan-
       dard, the original IEEE and The Open Group Standard is the referee  document.  The  original  Standard  can  be
       obtained online at http://www.opengroup.org/unix/online.html .



IEEE/The Open Group                  2003                             JOBS(1P)