freebsd-dev/usr.bin/nohup/nohup.1

.\" Copyright (c) 1989, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)nohup.1	8.1 (Berkeley) 6/6/93
.\" $FreeBSD$
.\"
.Dd July 19, 2001
.Dt NOHUP 1
.Os
.Sh NAME
.Nm nohup
.Nd invoke a utility immune to hangups
.Sh SYNOPSIS
.Nm
.Op Fl Fl
.Ar utility
.Op Ar arguments
.Sh DESCRIPTION
The
.Nm
utility invokes
.Ar utility
with its
.Ar arguments
and at this time sets the signal
.Dv SIGHUP
to be ignored.
If the standard output is a terminal, the standard output is
appended to the file
.Pa nohup.out
in the current directory.
If standard error is a terminal, it is directed to the same place
as the standard output.
.Pp
Some shells may provide a builtin
.Nm
command which is similar or identical to this utility.
Consult the
.Xr builtin 1
manual page.
.Sh ENVIRONMENT
The following variables are utilized by
.Nm :
.Bl -tag -width flag
.It Ev HOME
If the output file
.Pa nohup.out
cannot be created in the current directory, the
.Nm
utility uses the directory named by
.Ev HOME
to create the file.
.It Ev PATH
Used to locate the requested
.Ar utility
if the name contains no
.Ql /
characters.
.El
.Sh EXIT STATUS
The
.Nm
utility exits with one of the following values:
.Bl -tag -width Ds
.It 126
The
.Ar utility
was found, but could not be invoked.
.It 127
The
.Ar utility
could not be found or an error occurred in
.Nm .
.El
.Pp
Otherwise, the exit status of
.Nm
will be that of
.Ar utility .
.Sh SEE ALSO
.Xr builtin 1 ,
.Xr csh 1 ,
.Xr signal 3
.Sh STANDARDS
The
.Nm
utility is expected to be
.St -p1003.2
compatible.
.Sh BUGS
Two or more instances of
.Nm
can append to the same file, which makes for a confusing output.
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.\" Copyright (c) 1989, 1990, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" This code is derived from software contributed to Berkeley by`
			`.\" the Institute of Electrical and Electronics Engineers, Inc.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
			`.\" @(#)nohup.1 8.1 (Berkeley) 6/6/93`
$Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.\"`
mdoc(7) police: bump document date for the previous delta, fix markup. 2001-08-07 13:40:07 +00:00			`.Dd July 19, 2001`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Dt NOHUP 1`
			`.Os`
			`.Sh NAME`
			`.Nm nohup`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Nd invoke a utility immune to hangups`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Sh SYNOPSIS`
Use err(3). 1997-07-31 06:54:45 +00:00			`.Nm`
mdoc(7) police: bump document date for the previous delta, fix markup. 2001-08-07 13:40:07 +00:00			`.Op Fl Fl`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility`
Sync SYNOPSIS and usage() string. 2000-03-26 14:46:41 +00:00			`.Op Ar arguments`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Sh DESCRIPTION`
			`The`
Use err(3). 1997-07-31 06:54:45 +00:00			`.Nm`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`utility invokes`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility`
o Integrate security enhancements from OpenBSD. - Don't assume environment variable HOME is not NULL. o Integrate standards compliance from NetBSD. - Allow -- before the command. - Blocking SIGQUIT isn't standards compliant. - Proper exit(3) levels. - Actually append to nohup.out (as documented and required by standard) instead of clobbering it. o Remove some FreeBSD specific access(2) cruft (relating to incorrect appending). o Document the fact that two or more instances of nohup can append to the same file. o Constify; Staticize functions; Set WARNS?=2 Reviewed by: bde Approved by: des Obtained from: NetBSD, OpenBSD MFC after: 9 days 2001-07-19 21:25:10 +00:00			`with its`
Sync SYNOPSIS and usage() string. 2000-03-26 14:46:41 +00:00			`.Ar arguments`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`and at this time sets the signal`
			`.Dv SIGHUP`
Correct some hard sentence breaks. Only those surrounding the previous commit and those which cause ugly nroff output have been fixed, since the purpose of the style guideline which they contravene is to reduce the sizes of deltas. Reported by: bde 1999-09-14 11:46:04 +00:00			`to be ignored.`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`If the standard output is a terminal, the standard output is`
			`appended to the file`
			`.Pa nohup.out`
			`in the current directory.`
			`If standard error is a terminal, it is directed to the same place`
			`as the standard output.`
			`.Pp`
Improve shell documentation: * Consistently misspell built-in as builtin. * Add a builtin(1) manpage and create builtin(1) MLINKS for all shell builtin commands for which no standalone utility exists. These MLINKS replace those that were created for csh(1). * Add appropriate xrefs for builtin(1) to the csh(1) and sh(1) manpages, as well as to the manpages of standalone utilities which are supported as shell builtin commands in at least one of the shells. In such manpages, explain that similar functionality may be provided as a shell builtin command. * Improve sh(1)'s description of the cd builtin command. Csh(1) already describes it adequately. Replace the cd(1) manpage with a builtin(1) MLINKS link. * Clean up some mdoc problems: use Xr instead of literal "foo(n)"; use Ic instead of Xr for shell builtin commands. * Undo English contractions. Reviewed by: mpp, rgrimes 1999-09-08 15:40:46 +00:00			`Some shells may provide a builtin`
			`.Nm`
Correct some hard sentence breaks. Only those surrounding the previous commit and those which cause ugly nroff output have been fixed, since the purpose of the style guideline which they contravene is to reduce the sizes of deltas. Reported by: bde 1999-09-14 11:46:04 +00:00			`command which is similar or identical to this utility.`
			`Consult the`
Improve shell documentation: * Consistently misspell built-in as builtin. * Add a builtin(1) manpage and create builtin(1) MLINKS for all shell builtin commands for which no standalone utility exists. These MLINKS replace those that were created for csh(1). * Add appropriate xrefs for builtin(1) to the csh(1) and sh(1) manpages, as well as to the manpages of standalone utilities which are supported as shell builtin commands in at least one of the shells. In such manpages, explain that similar functionality may be provided as a shell builtin command. * Improve sh(1)'s description of the cd builtin command. Csh(1) already describes it adequately. Replace the cd(1) manpage with a builtin(1) MLINKS link. * Clean up some mdoc problems: use Xr instead of literal "foo(n)"; use Ic instead of Xr for shell builtin commands. * Undo English contractions. Reviewed by: mpp, rgrimes 1999-09-08 15:40:46 +00:00			`.Xr builtin 1`
			`manual page.`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Sh ENVIRONMENT`
Document the fairly obvious effects of the PATH environment variable. 2002-06-28 09:31:03 +00:00			`The following variables are utilized by`
mdoc(7) police: use the new features of the Nm macro. 2000-11-20 19:21:22 +00:00			`.Nm :`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Bl -tag -width flag`
			`.It Ev HOME`
			`If the output file`
			`.Pa nohup.out`
			`cannot be created in the current directory, the`
Use err(3). 1997-07-31 06:54:45 +00:00			`.Nm`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`utility uses the directory named by`
			`.Ev HOME`
			`to create the file.`
Document the fairly obvious effects of the PATH environment variable. 2002-06-28 09:31:03 +00:00			`.It Ev PATH`
			`Used to locate the requested`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility`
Document the fairly obvious effects of the PATH environment variable. 2002-06-28 09:31:03 +00:00			`if the name contains no`
			`.Ql /`
			`characters.`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.El`
Added the EXIT STATUS section where appropriate. 2005-01-17 07:44:44 +00:00			`.Sh EXIT STATUS`
o Integrate security enhancements from OpenBSD. - Don't assume environment variable HOME is not NULL. o Integrate standards compliance from NetBSD. - Allow -- before the command. - Blocking SIGQUIT isn't standards compliant. - Proper exit(3) levels. - Actually append to nohup.out (as documented and required by standard) instead of clobbering it. o Remove some FreeBSD specific access(2) cruft (relating to incorrect appending). o Document the fact that two or more instances of nohup can append to the same file. o Constify; Staticize functions; Set WARNS?=2 Reviewed by: bde Approved by: des Obtained from: NetBSD, OpenBSD MFC after: 9 days 2001-07-19 21:25:10 +00:00			`The`
			`.Nm`
			`utility exits with one of the following values:`
			`.Bl -tag -width Ds`
			`.It 126`
			`The`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility`
o Integrate security enhancements from OpenBSD. - Don't assume environment variable HOME is not NULL. o Integrate standards compliance from NetBSD. - Allow -- before the command. - Blocking SIGQUIT isn't standards compliant. - Proper exit(3) levels. - Actually append to nohup.out (as documented and required by standard) instead of clobbering it. o Remove some FreeBSD specific access(2) cruft (relating to incorrect appending). o Document the fact that two or more instances of nohup can append to the same file. o Constify; Staticize functions; Set WARNS?=2 Reviewed by: bde Approved by: des Obtained from: NetBSD, OpenBSD MFC after: 9 days 2001-07-19 21:25:10 +00:00			`was found, but could not be invoked.`
			`.It 127`
			`The`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility`
o Integrate security enhancements from OpenBSD. - Don't assume environment variable HOME is not NULL. o Integrate standards compliance from NetBSD. - Allow -- before the command. - Blocking SIGQUIT isn't standards compliant. - Proper exit(3) levels. - Actually append to nohup.out (as documented and required by standard) instead of clobbering it. o Remove some FreeBSD specific access(2) cruft (relating to incorrect appending). o Document the fact that two or more instances of nohup can append to the same file. o Constify; Staticize functions; Set WARNS?=2 Reviewed by: bde Approved by: des Obtained from: NetBSD, OpenBSD MFC after: 9 days 2001-07-19 21:25:10 +00:00			`could not be found or an error occurred in`
			`.Nm .`
			`.El`
			`.Pp`
			`Otherwise, the exit status of`
			`.Nm`
			`will be that of`
Refer to utilities, not commands, for consistency with env(1), nice(1), etc. 2002-06-28 09:34:46 +00:00			`.Ar utility .`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Sh SEE ALSO`
Improve shell documentation: * Consistently misspell built-in as builtin. * Add a builtin(1) manpage and create builtin(1) MLINKS for all shell builtin commands for which no standalone utility exists. These MLINKS replace those that were created for csh(1). * Add appropriate xrefs for builtin(1) to the csh(1) and sh(1) manpages, as well as to the manpages of standalone utilities which are supported as shell builtin commands in at least one of the shells. In such manpages, explain that similar functionality may be provided as a shell builtin command. * Improve sh(1)'s description of the cd builtin command. Csh(1) already describes it adequately. Replace the cd(1) manpage with a builtin(1) MLINKS link. * Clean up some mdoc problems: use Xr instead of literal "foo(n)"; use Ic instead of Xr for shell builtin commands. * Undo English contractions. Reviewed by: mpp, rgrimes 1999-09-08 15:40:46 +00:00			`.Xr builtin 1 ,`
			`.Xr csh 1 ,`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.Xr signal 3`
			`.Sh STANDARDS`
			`The`
Use err(3). 1997-07-31 06:54:45 +00:00			`.Nm`
			`utility is expected to be`
BSD 4.4 Lite Usr.bin Sources 1994-05-27 12:33:43 +00:00			`.St -p1003.2`
			`compatible.`
o Integrate security enhancements from OpenBSD. - Don't assume environment variable HOME is not NULL. o Integrate standards compliance from NetBSD. - Allow -- before the command. - Blocking SIGQUIT isn't standards compliant. - Proper exit(3) levels. - Actually append to nohup.out (as documented and required by standard) instead of clobbering it. o Remove some FreeBSD specific access(2) cruft (relating to incorrect appending). o Document the fact that two or more instances of nohup can append to the same file. o Constify; Staticize functions; Set WARNS?=2 Reviewed by: bde Approved by: des Obtained from: NetBSD, OpenBSD MFC after: 9 days 2001-07-19 21:25:10 +00:00			`.Sh BUGS`
			`Two or more instances of`
			`.Nm`
			`can append to the same file, which makes for a confusing output.`