nohup man page on SuSE

Man page or keyword search:  
man Server   14857 pages
apropos Keyword Search (all sections)
Output format
SuSE logo
[printable version]

NOHUP(1P)		   POSIX Programmer's Manual		     NOHUP(1P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the	 corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.

NAME
       nohup - invoke a utility immune to hangups

SYNOPSIS
       nohup utility [argument...]

DESCRIPTION
       The nohup utility shall invoke the utility named by the utility operand
       with arguments supplied as the argument operands. At the time the named
       utility is invoked, the SIGHUP signal shall be set to be ignored.

       If the standard output is a terminal, all output written by  the	 named
       utility to its standard output shall be appended to the end of the file
       nohup.out in the current directory. If nohup.out cannot be  created  or
       opened  for  appending,	the output shall be appended to the end of the
       file nohup.out in the directory specified by the HOME environment vari‐
       able.  If  neither file can be created or opened for appending, utility
       shall not be invoked. If a file is created, the file's permission  bits
       shall be set to S_IRUSR | S_IWUSR.

       If  the	standard  error is a terminal, all output written by the named
       utility to its standard error shall be  redirected  to  the  same  file
       descriptor as the standard output.

OPTIONS
       None.

OPERANDS
       The following operands shall be supported:

       utility
	      The  name of a utility that is to be invoked. If the utility op‐
	      erand names any of the special  built-in	utilities  in  Special
	      Built-In Utilities, the results are undefined.

       argument
	      Any string to be supplied as an argument when invoking the util‐
	      ity named by the utility operand.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       The following environment  variables  shall  affect  the	 execution  of
       nohup:

       HOME   Determine the pathname of the user's home directory: if the out‐
	      put file nohup.out cannot be created in the  current  directory,
	      the  nohup utility shall use the directory named by HOME to cre‐
	      ate the file.

       LANG   Provide a default value for the  internationalization  variables
	      that  are	 unset	or  null.  (See the Base Definitions volume of
	      IEEE Std 1003.1-2001, Section  8.2,  Internationalization	 Vari‐
	      ables  for the precedence of internationalization variables used
	      to determine the values of locale categories.)

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

       LC_CTYPE
	      Determine	 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
	      Determine	 the  locale  that should be used to affect the format
	      and contents of diagnostic messages written to standard error.

       NLSPATH
	      Determine the location of message catalogs for the processing of
	      LC_MESSAGES .

       PATH   Determine	 the search path that is used to locate the utility to
	      be   invoked.   See   the	   Base	   Definitions	  volume    of
	      IEEE Std 1003.1-2001, Chapter 8, Environment Variables.

ASYNCHRONOUS EVENTS
       The nohup utility shall take the standard action for all signals except
       that SIGHUP shall be ignored.

STDOUT
       If the standard output is not a terminal, the standard output of	 nohup
       shall  be the standard output generated by the execution of the utility
       specified by the operands. Otherwise, nothing shall be written  to  the
       standard output.

STDERR
       If the standard output is a terminal, a message shall be written to the
       standard error, indicating the name of the file to which the output  is
       being  appended.	 The  name  of	the  file shall be either nohup.out or
       $HOME/nohup.out.

OUTPUT FILES
       If the standard output is a terminal, all output written by  the	 named
       utility	to  the	 standard output and standard error is appended to the
       file nohup.out, which is created if it does not already exist.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

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

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

       Otherwise, the exit status of nohup shall be that of the utility speci‐
       fied by the utility operand.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       The  command,  env,  nice,  nohup,  time, and xargs utilities have been
       specified to use exit code 127 if an error occurs so that  applications
       can  distinguish	 "failure  to  find  a	utility" from "invoked utility
       exited with an error indication". The value 127 was chosen  because  it
       is  not commonly used for other meanings; most utilities use small val‐
       ues for "normal error conditions" and the values above 128 can be  con‐
       fused  with  termination	 due to receipt of a signal. The value 126 was
       chosen in a similar manner to indicate that the utility could be found,
       but not invoked. Some scripts produce meaningful error messages differ‐
       entiating the 126 and 127 cases. The distinction between exit codes 126
       and  127 is based on KornShell practice that uses 127 when all attempts
       to exec the utility fail with [ENOENT], and uses 126 when  any  attempt
       to exec the utility fails for any other reason.

EXAMPLES
       It is frequently desirable to apply nohup to pipelines or lists of com‐
       mands. This can be done by placing pipelines and	 command  lists	 in  a
       single  file; this file can then be invoked as a utility, and the nohup
       applies to everything in the file.

       Alternatively, the following command can be used to apply  nohup	 to  a
       complex command:

	      nohup sh -c 'complex-command-line'

RATIONALE
       The 4.3 BSD version ignores SIGTERM and SIGHUP, and if ./nohup.out can‐
       not be used, it fails instead of trying to use $HOME/nohup.out.

       The csh utility has a built-in version of nohup that  acts  differently
       from the nohup defined in this volume of IEEE Std 1003.1-2001.

       The  term  utility  is used, rather than command, to highlight the fact
       that shell compound commands, pipelines, special built-ins, and so  on,
       cannot  be  used	 directly.  However, utility includes user application
       programs and shell scripts, not just the standard utilities.

       Historical versions of the nohup	 utility  use  default	file  creation
       semantics. Some more recent versions use the permissions specified here
       as an added security precaution.

       Some historical implementations ignore SIGQUIT in addition  to  SIGHUP;
       others  ignore SIGTERM. An early proposal allowed, but did not require,
       SIGQUIT to be ignored. Several reviewers	 objected  that	 nohup	should
       only  modify  the  handling  of	SIGHUP	as  required by this volume of
       IEEE Std 1003.1-2001.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Shell  Command  Language,  sh,  the   System   Interfaces   volume   of
       IEEE Std 1003.1-2001, signal()

COPYRIGHT
       Portions	 of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating	System	Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003	by  the	 Institute  of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained	online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group		     2003			     NOHUP(1P)
[top]

List of man pages available for SuSE

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net