bg - Runs jobs in the background
The C shell has a built-in version of the bg command. If
you are using the C shell, and want to guarantee that you
are using the command described here, you must specify the
full path /usr/bin/bg. See the csh(1) reference page for
a description of the built-in command.
Interfaces documented on this reference page conform to
industry standards as follows:
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Specifies the job to be resumed as a background job. If no
job_id operand is given, the most recently suspended job
is used. The format of job_id is described in the Jobs
section of the ksh(1) reference page.
If job control is enabled (see the description of set -m
in the ksh(1) reference page), the bg utility resumes suspended
jobs from the current environment by running them
as background jobs. If the job specified by job_id is a
job already running in the background, the bg utility has
no effect and will exit 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 been started as an asynchronous
list. See the Jobs section of the ksh(1) reference page.
If job control is disabled, the bg utility exits with an
error and no job is placed in the background. The bg
utility does not work as expected when it is operating in
its own utility execution environment because that environment
has no suspended jobs.
The following exit values are returned: Successful completion.
An error occurred.
ENVIRONMENT VARIABLES [Toc] [Back]
The following environment variables affect the execution
of bg: Provides a default value for the internationalization
variables that are unset or null. If LANG is unset or
null, the corresponding value from the default locale is
used. If any of the internationalization variables contain
an invalid setting, the utility behaves as if none of
the variables had been defined. If set to a non-empty
string value, overrides the values of all the other internationalization
variables. Determines the locale for the
interpretation of sequences of bytes of text data as characters
(for example, single-byte as opposed to multibyte
characters in arguments). Determines the locale used to
affect the format and contents of diagnostic messages
written to standard error. Determines the location of
message catalogues for the processing of LC_MESSAGES.
Commands: csh(1), fg(1), jobs(1), kill(1), ksh(1), Bourne
shell sh(1b), POSIX shell sh(1p), wait(1)
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