User Commands jobs(1)
NAME
jobs, fg, bg, stop, notify - control process execution
SYNOPSIS
shjobs [-p | -l] [% job_id...]
jobs -x command [arguments]
fg [% job_id...]
bg [% job_id...]
stop % job_id...
stop pid... cshjobs [-l]
fg [% job_id]
bg [% job_id]...
notify [% job_id]...
stop % job_id...
stop pid... kshjobs [-lnp] [% job_id...]
fg [% job_id...]
bg [% job_id...]
SunOS 5.11 Last change: 2 Nov 2007 1
User Commands jobs(1)stop % job_id...
stop pid... ksh93jobs [-lnp] [job_id...]
fg [job_id...]
bg [job_id...]
DESCRIPTION
shWhen Job Control is enabled, the Bourne shell built-in jobs
reports all jobs that are stopped or executing in the back-
ground. If %job_id is omitted, all jobs that are stopped or
running in the background is reported. The following options modify or enhance the output of jobs:-l Reports the process group ID and working directory of
the jobs.-p Reports only the process group ID of the jobs.
-x Replaces any job_id found in command or arguments with
the corresponding process group ID, and then executes command passing it arguments. When the shell is invoked as jsh, Job Control is enabled in addition to all of the functionality described previously for sh. Typically Job Control is enabled for the interactiveshell only. Non-interactive shells typically do not benefit
from the added functionality of Job Control. With Job Control enabled every command or pipeline the userenters at the terminal is called a job_id. All jobs exist in
one of the following states: foreground, background or stopped. These terms are defined as follows: 1. A job in the foreground has read and write access to the controlling terminal.SunOS 5.11 Last change: 2 Nov 2007 2
User Commands jobs(1) 2. A job in the background is denied read access and has conditional write access to the controlling terminal (see stty(1)) 3. A stopped job is a job that has been placed in a suspended state, usually as a result of a SIGTSTP signal (see signal.h(3HEAD)). Every job that the shell starts is assigned a positiveinteger, called a job_id number which is tracked by the
shell and are used as an identifier to indicate a specific job. Additionally, the shell keeps track of the current and previous jobs. The current job is the most recent job to bestarted or restarted. The previous job is the first non-
current job. The acceptable syntax for a Job Identifier is of the form:%job_id
where job_id can be specified in any of the following for-
mats:% or + for the current job
- for the previous job
?specify the job for which the command line uniquely contains string. n for job number n, where n is a job number pref where pref is a unique prefix of the command name (for example, if the command ls -l name
were running in the background, it could bereferred to as %ls); pref cannot contain blanks
unless it is quoted. When Job Control is enabled, fg resumes the execution of astopped job in the foreground, also moves an executing back-
ground job into the foreground. If %job_id is omitted the
current job is assumed.SunOS 5.11 Last change: 2 Nov 2007 3
User Commands jobs(1)When Job Control is enabled, bg resumes the execution of a
stopped job in the background. If %job_id is omitted the
current job is assumed. stop stops the execution of a background job(s) by using itsjob_id, or of any process by using its pid; see ps(1).
cshThe C shell built-in, jobs, without an argument, lists the
active jobs under job control.-l List process IDs, in addition to the normal informa-
tion.The shell associates a numbered job_id with each command
sequence to keep track of those commands that are running inthe background or have been stopped with TSTP signals (typi-
cally Control-Z). When a command or command sequence
(semicolon-separated list) is started in the background
using the & metacharacter, the shell displays a line with the job number in brackets and a list of associated process numbers: [1] 1234To see the current list of jobs, use the jobs built-in com-
mand. The job most recently stopped (or put into the back-
ground if none are stopped) is referred to as the currentjob and is indicated with a `+'. The previous job is indi-
cated with a `-'; when the current job is terminated or
moved to the foreground, this job takes its place (becomes the new current job).To manipulate jobs, refer to the bg, fg, kill, stop, and %
built-in commands.
A reference to a job begins with a `%'. By itself, the per-
cent sign refers to the current job.% %+ %% The current job.
%- The previous job.
SunOS 5.11 Last change: 2 Nov 2007 4
User Commands jobs(1)%j Refer to job j as in: `kill -9 %j'. j can be a
job number, or a string that uniquely specifies the command line by which it was started; `fg%vi' might bring a stopped vi job to the fore-
ground, for instance.%?string Specify the job for which the command line
uniquely contains string. A job running in the background stops when it attempts to read from the terminal. Background jobs can normally produce output, but this can be suppressed using the `stty tostop' command.fg brings the current or specified job_id into the fore-
ground.bg runs the current or specified jobs in the background.
stop stops the execution of a background job(s) by using itsjob_id, or of any process by using its pid; see ps(1).
notify notifies the user asynchronously when the status of the current job or specified jobs changes. ksh jobs displays the status of the jobs that were started inthe current shell environment. When jobs reports the termi-
nation status of a job, the shell removes its process ID from the list of those known in the current shell execution environment.job_id specifies the jobs for which the status is to be
displayed. If no job_id is specified, the status information
for all jobs are displayed. The following options modify or enhance the output of jobs:-l (The letter ell.) Provides more information about each
job listed. This information includes the job number, current job, process group ID, state and the command that formed the job.SunOS 5.11 Last change: 2 Nov 2007 5
User Commands jobs(1)-n Displays only jobs that have stopped or exited since
last notified.-p Displays only the process IDs for the process group
leaders of the selected jobs. By default, jobs displays the status of all the stopped jobs, running background jobs, and all jobs whose status has changed and have not been reported by the shell. If the monitor option of the set command is turned on, an interactive shell associates a job with each pipeline. It keeps a table of current jobs, printed by the jobs command, and assigns them small integer numbers. When a job is started asynchronously with &, the shell prints a line which looks like: [1] 1234 indicating that the job, which was started asynchronously,was job number 1 and had one (top-level) process, whose pro-
cess id was 1234. If you are running a job and wish to do something else youcan hit the key ^Z (Control-Z) which sends a STOP signal to
the current job. The shell then normally indicates that thejob has been "Stopped" (see OUTPUT below), and print another
prompt. You can then manipulate the state of this job, put-
ting it in the background with the bg command, or run some
other commands and then eventually bring the job back into the foreground with the foreground command fg. A ^Z takes effect immediately and is like an interrupt, in that pending output and unread input are discarded when it is typed. There are several ways to refer to jobs in the shell. A job can be referred to by the process id of any process of the job or by one of the following:%number The job with the specified number.
%string Any job whose command line begins with string;
works only in the interactive mode when the his-
tory file is active.SunOS 5.11 Last change: 2 Nov 2007 6
User Commands jobs(1)%?string Any job whose command line contains string;
works only in the interactive mode when the his-
tory file is active.%% Current job.
%+ Equivalent to %%.
%- Previous job.
The shell learns immediately whenever a process changes state. It normally informs you whenever a job becomes blocked so that no further progress is possible, but only just before it prints a prompt. This is done so that it does not otherwise disturb your work. When the monitor mode is on, each background job that completes triggers any trap set for CHLD. When you try to leave the shell while jobs are running or stopped, you are warned that `You have stopped (running) jobs.' You can use the jobs command to see what they are. If you do this or immediately try to exit again, the shell does not warn you a second time, and the stopped jobs are terminated. fg moves a background job from the current environment into the foreground. Using fg to place a job in the foreground removes its process ID from the list of those known in the current shell execution environment. The fg command is available only on systems that support job control. Ifjob_id is not specified, the current job is brought into the
foreground.bg resumes suspended jobs from the current environment by
running them as background jobs. If the job specified byjob_id is already a running background job, bg has no effect
and exits successfully. Using bg to place a job into the
background causes its process ID to become `known in the current shell execution environment, as if it had beenstarted as an asynchronous list. The bg command is available
only on systems that support job control. If job_id is not
specified, the current job is placed in the background. stop stops the execution of a background job(s) by using itsjob_id, or of any process by using its pid. See ps(1).
SunOS 5.11 Last change: 2 Nov 2007 7
User Commands jobs(1) ksh93 jobs displays information about specified jobs that were started by the current shell environment on standard output. The information contains the job number enclosed in [...], the status, and the command line that started the job.If job_id is omitted, jobs displays the status of all
stopped jobs, background jobs, and all jobs whose status has changed since last reported by the shell. When jobs reports the termination status of a job, the shell removes the job from the list of known jobs in the current shell environment. The following options modify or enhances the output of jobs:-l Displays process IDs after the job number in addition
to the usual information.-n Displays only the jobs whose status has changed since
the last prompt was displayed.-p Displays the process group leader IDs for the speci-
fied jobs.job_id can be specified to jobs, fg, and bg as one of the
following: number The process id of job.-number The process group id of job.
%number The job number.
%string The job whose name begins with string.
%?string The job whose name contains string.
%+
%%
SunOS 5.11 Last change: 2 Nov 2007 8
User Commands jobs(1) The current job.%- The previous job.
fg places the specified jobs into the foreground in sequenceand sends a CONT signal to start each running. If job_id is
omitted, the most recently started or stopped background job is moved to the foreground.bg places the specified jobs into the background and sends a
CONT signal to start them running. If job_id is omitted, the
most recently started or stopped background job is resumed or continued in the background.OUTPUT
If the -p option is specified, the output consists of one
line for each process ID:"%d\n", "process ID"
Otherwise, if the -l option is not specified, the output is
a series of lines of the form:"[%d] %c %s %s\n", job-number, current, state, command
where the fields are as follows: current The character + identifies the job that wouldbe used as a default for the fg or bg com-
mands. This job can also be specified usingthe job_id %+ or %% . The character - identi-
fies the job that would become the default if the current default job were to exit; this jobcan also be specified using the job_id %- .
For other jobs, this field is a space charac-
ter. 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 is a suspended job. If there are at least two suspended jobs, then the previous job is also a suspended job.SunOS 5.11 Last change: 2 Nov 2007 9
User Commands jobs(1)job-number A number that can be used to identify the pro-
cess group to the wait, fg, bg, and kill util-
ities. Using these utilities, the job can beidentified 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 thespecified non-zero exit
status, code, expressed as a decimal number. Stopped Indicates that the job was stopped. 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 can substitute the string Suspended in place of Stopped. If the job wasSunOS 5.11 Last change: 2 Nov 2007 10
User Commands jobs(1) terminated by a signal, the format of state is unspecified, but it is visibly distinct from all of the other state formats shown here andindicates the name or description of the sig-
nal causing the termination. command The associated command that was specified to the shell.If the -l option is specified, a field containing the pro-
cess group ID is inserted before the state field. Also, more processes in a process group can be output on separate lines, using only the process ID and command fields. ENVIRONMENT VARIABLES See environ(5) for descriptions of the following environmentvariables that affect the execution of jobs, fg, and bg:
LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
EXIT STATUS sh, csh, kshThe following exit values are returned for jobs, fg, and bg:
0 Successful completion. >0 An error occurred. ksh93 The following exit values are returned for jobs: 0 The information for each job is written to standard output. >0 One or more jobs does not exist. The following exit values are returned for fg: exit status of last job One or more jobs has been brought into the foreground.non-zero One or more jobs does not exist
or has completed.SunOS 5.11 Last change: 2 Nov 2007 11
User Commands jobs(1)The following exit values are returned for bg:
0 All background jobs are started.>0 One more jobs does not exist or there are no back-
ground jobs.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes: csh, sh, ksh____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcs ||_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| Standard | See standards(5). ||_____________________________|_____________________________|
ksh93____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcsu ||_____________________________|_____________________________|
| Interface Stability | Uncommitted ||_____________________________|_____________________________|
SEE ALSO
csh(1), kill(1), ksh(1), ksh93(1), ps(1), sh(1), stop(1),shell_builtins(1), stty(1), wait(1), signal.h(3HEAD), attri-
butes(5), environ(5), standards(5)SunOS 5.11 Last change: 2 Nov 2007 12