Gnu/coreutils/nohup-invocation
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23.4 nohup
: Run a command immune to hangups
nohup
runs the given command
with hangup signals ignored,
so that the command can continue running in the background after you log
out. Synopsis:
nohup command [arg]…
If standard input is a terminal, redirect it so that terminal sessions
do not mistakenly consider the terminal to be used by the command.
Make the substitute file descriptor unreadable, so that commands that
mistakenly attempt to read from standard input can report an error.
This redirection is a GNU extension; programs intended to be portable
to non-GNU hosts can use ‘nohup command [arg]… 0>/dev/null
’ instead.
If standard output is a terminal, the command’s standard output is appended
to the file nohup.out
; if that cannot be written to, it is appended
to the file $HOME/nohup.out
; and if that cannot be written to, the
command is not run.
Any nohup.out
or $HOME/nohup.out
file created by
nohup
is made readable and writable only to the user,
regardless of the current umask settings.
If standard error is a terminal, it is normally redirected to the same file
descriptor as the (possibly-redirected) standard output.
However, if standard output is closed, standard error terminal output
is instead appended to the file nohup.out
or
$HOME/nohup.out
as above.
To capture the command’s output to a file other than nohup.out
you can redirect it. For example, to capture the output of
make
:
nohup make > make.log
nohup
does not automatically put the command it runs in the
background; you must do that explicitly, by ending the command line
with an ‘&
’. Also, nohup
does not alter the
niceness of command
; use nice
for that,
e.g., ‘nohup nice command
’.
command
must not be a special built-in utility (see Special built-in utilities).
The only options are --help
and --version
. See Common options. Options must precede operands.
Exit status:
125 if nohup itself fails, and POSIXLY_CORRECT is not set 126 if command is found but cannot be invoked 127 if command cannot be found the exit status of command otherwise
If POSIXLY_CORRECT
is set, internal failures give status 127
instead of 125.
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