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7.2 Job Control Builtins
bg
-
bg [jobspec]
Resume the suspended job jobspec in the background, as if it
had been started with '&'.
If jobspec is not supplied, the current job is used.
The return status is zero unless it is run when job control is not
enabled, or, when run with job control enabled, if jobspec was
not found or jobspec specifies a job that was started without
job control.
fg
-
fg [jobspec]
Resume the job jobspec in the foreground and make it the current job.
If jobspec is not supplied, the current job is used.
The return status is that of the command placed into the foreground,
or non-zero if run when job control is disabled or, when run with
job control enabled, jobspec does not specify a valid job or
jobspec specifies a job that was started without job control.
jobs
-
jobs [-lnprs] [jobspec]
jobs -x command [arguments]
The first form lists the active jobs. The options have the
following meanings:
-l
-
List process IDs in addition to the normal information.
-n
-
Display information only about jobs that have changed status since
the user was last notified of their status.
-p
-
List only the process ID of the job's process group leader.
-r
-
Restrict output to running jobs.
-s
-
Restrict output to stopped jobs.
If jobspec is given,
output is restricted to information about that job.
If jobspec is not supplied, the status of all jobs is
listed.
If the -x option is supplied, jobs replaces any
jobspec found in command or arguments with the
corresponding process group ID, and executes command,
passing it arguments, returning its exit status.
kill
-
kill [-s sigspec] [-n signum]
[-sigspec] jobspec or pid
kill -l [exit_status]
Send a signal specified by sigspec or signum to the process
named by job specification jobspec or process ID pid.
sigspec is either a signal name such as SIGINT (with or without
the SIG prefix) or a signal number; signum is a signal number.
If sigspec and signum are not present, SIGTERM is used.
The -l option lists the signal names.
If any arguments are supplied when -l is given, the names of the
signals corresponding to the arguments are listed, and the return status
is zero.
exit_status is a number specifying a signal number or the exit
status of a process terminated by a signal.
The return status is zero if at least one signal was successfully sent,
or non-zero if an error occurs or an invalid option is encountered.
wait
-
wait [jobspec or pid]
Wait until the child process specified by process ID pid or job
specification jobspec exits and return the exit status of the last
command waited for.
If a job spec is given, all processes in the job are waited for.
If no arguments are given, all currently active child processes are
waited for, and the return status is zero.
If neither jobspec nor pid specifies an active child process
of the shell, the return status is 127.
disown
-
disown [-ar] [-h] [jobspec ...]
Without options, each jobspec is removed from the table of
active jobs.
If the -h option is given, the job is not removed from the table,
but is marked so that SIGHUP is not sent to the job if the shell
receives a SIGHUP .
If jobspec is not present, and neither the -a nor -r
option is supplied, the current job is used.
If no jobspec is supplied, the -a option means to remove or
mark all jobs; the -r option without a jobspec
argument restricts operation to running jobs.
suspend
-
suspend [-f]
Suspend the execution of this shell until it receives a
SIGCONT signal. The -f option means to suspend
even if the shell is a login shell.
When job control is not active, the kill and wait
builtins do not accept jobspec arguments. They must be
supplied process IDs.
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