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nohup(1)							     nohup(1)



NAME

  nohup	- Runs a utility ignoring hangups and quits

SYNOPSIS

  nohup	utility	[argument...]

				     Note

       The C shell has a built-in version of the nohup command.	 If you	are
       using the C shell, and want to guarantee	that you are using the com-
       mand described here, you	must specify the full path /usr/bin/nohup.
       See the csh(1) reference	page for a description of the built-in com-
       mand.

STANDARDS

  Interfaces documented	on this	reference page conform to industry standards
  as follows:

  nohup:  XCU5.0

  Refer	to the standards(5) reference page for more information	about indus-
  try standards	and associated tags.

OPTIONS

  None

OPERANDS

  utility
      The name of a command to be invoked.

  argument
      Optional arguments required by the utility specified for invokation.

DESCRIPTION

  The nohup command runs utility, ignoring all hangups and QUIT	signals.  You
  can use this command to run programs in the background after logging off
  the system.  To run a	nohup command in the background, add an	& (ampersand)
  to the end of	the command.

  If nohup output is redirected	to a terminal or is not	redirected at all,
  the output is	appended to the	file nohup.out.	 If the	file is	created, the
  permission bits are set to Owner Read	and Owner Write	(600). If nohup.out
  is not writable in the current directory, the	output is redirected to
  $HOME/nohup.out.  If neither file can	be created nor opened for appending,
  utility is not invoked.


  If standard error is a terminal, all output written to standard error	is
  appended to the file receiving standard output.

  The nohup command accepts just one utility as	an argument.  To apply nohup
  to a pipeline	or list	of commands, enter the pipeline	or list	in a shell
  script file.	Then run sh as utility using the following format:

  nohup	sh -c file

  [Tru64 UNIX]	You can	also assign the	shell file execute permission and run
  it as	the utility in the form:

  nohup	file

NOTES

  The term utility, rather than	the term command, describes the	argument to
  nohup	because	shell compound commands, pipelines, special built-in pro-
  grams, and the like, cannot be handled directly. In addition,	the term
  utility includes user	application programs and shell scripts,	not just the
  standard utilities.

EXIT STATUS

  The nohup command returns the	following exit values:

  126 The specified utility was	found, but could not be	invoked.

  127 The error	occurred in the	nohup utility or the specified utility could
      not be found.

  The exit status is otherwise that of the utility.

EXAMPLES

   1.  To leave	a command running after	logging	out (sh	only), enter:
	    nohup  find	 /  -print  &&

       Shortly after you enter this, the following is displayed:
	    670
	    $ Sending output to	nohup.out

       The process ID number changes to	the background process started by the
       & (ampersand), in this case, 670.  The $	(dollar	sign) is the shell
       prompt.	The message following informs you that the output from the
       find command is in the file nohup.out.
	    Sending output...

       You can log out after you see these messages, even if the find command
       has not finished	yet.

       If you are using	csh, the built-in command nohup	is executed instead
       of the system command.  To execute the nohup system command, you	must
       enter an	absolute path.

   2.  To do the same, but redirect the	standard output	to a different file,
       enter:
	    nohup  find	 /  -print  >>filenames	&&

       This runs the find command and stores its output	in a file named
       filenames. Now only the process ID and prompt are displayed.

       Wait for	a second or two	before logging out, because the	nohup command
       takes a moment to start the command you specified. If you log out too
       quickly,	utility	may not	run at all.  Once utility has started, log-
       ging out	does not affect	it.

   3.  To run more than	one command, use a shell script.  For example, if you
       include the following shell script:
	    comm -23 fi4 fi5 | comm -23	- fi6 |	join -a1 - fi7 >> comm.out

       and name	it ncomm, you can run nohup for	all of the commands in ncomm
       by entering:
	    nohup sh ncomm

       If you assign ncomm Execute permission, you can obtain the same
       results by issuing the command:
	    nohup ncomm

       To run this command in the background, enter:
	    nohup ncomm	&&



ENVIRONMENT VARIABLES

  The following	environment variables affect the execution of nohup:

  LANG
      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.

  LC_ALL
      If set to	a non-empty string value, overrides the	values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for	the interpretation of sequences	of bytes of
      text data	as characters (for example, single-byte	as opposed to multi-
      byte characters in arguments).

  LC_MESSAGES
      Determines the locale for	the format and contents	of diagnostic mes-
      sages written to standard	error.

  NLSPATH
      Determines the location of message catalogues for	the processing of
      LC_MESSAGES.

  PATH
      Determines the search path that will be used to locate the command to
      be invoked.

FILES

  nohup.out
      Standard output and standard error file for nohup.

SEE ALSO

  Commands:  csh(1), ksh(1), nice(1), Bourne shell sh(1b), POSIX shell sh(1p)

  Functions:  sigaction(2)

  Standards:  standards(5)