NAME

nohup − run a command immune to hangups, logouts, and quits

SYNOPSIS

nohup command [ arguments ]

DESCRIPTION

Nohup executes command with hangups and quits ignored.  If output is not re-directed by the user, both standard output and standard error are sent to nohup.out.  If nohup.out is not writable in the current directory, output is redirected to $HOME/nohup.out; otherwise, nohup will fail. 

If output from nohup is redirected to a terminal, or is not redirected at all, the output is sent to nohup.out. 

EXAMPLE

It is frequently desirable to apply nohup to pipelines or lists of commands.  This can be done only by placing pipelines and command lists in a single file, called a shell procedure.  One can then issue:

nohup sh file

and the nohup applies to everything in file.  If the shell procedure file is to be executed often, then the need to type sh can be eliminated by giving file execute permission.  Add an ampersand and the contents of file are run in the background with interrupts also ignored (see sh(1)):

nohup file &

An example of what the contents of file could be is:

tbl ofile | eqn | nroff > nfile

SEE ALSO

chmod(1), nice(1), sh(1), signal(2). 

WARNINGS

Be careful to place punctuation properly, for example in the following command:

nohup command1; command2

nohup applies only to command1, and the following command is syntactically incorrect:

nohup (command1; command2)

Be careful of where standard error is redirected.  The following command may put error messages on tape, making it unreadable:

nohup cpio −o <list >/dev/rmt/1m&

while

nohup cpio −o <list >/dev/rmt/1m 2>errors&

puts the error messages into file errors.

INTERNATIONAL SUPPORT

8- and 16-bit data, 8-bit filenames. 

Hewlett-Packard Company  —  May 11, 2021