xref: /openbsd/usr.bin/nohup/nohup.1 (revision 09467b48)
1.\"	$OpenBSD: nohup.1,v 1.16 2010/09/29 07:44:56 jmc Exp $
2.\"	$NetBSD: nohup.1,v 1.5 1995/08/31 23:35:24 jtc Exp $
3.\"
4.\" Copyright (c) 1989, 1990, 1993
5.\"	The Regents of the University of California.  All rights reserved.
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7.\" This code is derived from software contributed to Berkeley by
8.\" the Institute of Electrical and Electronics Engineers, Inc.
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34.\"	@(#)nohup.1	8.1 (Berkeley) 6/6/93
35.\"
36.Dd $Mdocdate: September 29 2010 $
37.Dt NOHUP 1
38.Os
39.Sh NAME
40.Nm nohup
41.Nd invoke a command immune to hangups
42.Sh SYNOPSIS
43.Nm nohup
44.Ar utility
45.Op Ar arg ...
46.Sh DESCRIPTION
47The
48.Nm
49command allows the specified utility to be protected from termination
50if the user should become logged out
51(for example, due to a modem line or TCP/IP connection being dropped).
52To do this,
53.Nm
54sets the
55.Dv SIGHUP
56.Xr signal 3
57.Pq Dq terminal line hangup
58to be ignored,
59then executes
60.Ar utility
61along with any arguments.
62.Pp
63If the standard output is a terminal, the standard output is
64appended to the file
65.Pa nohup.out
66in the current directory.
67If standard error is a terminal, it is directed to the same place
68as the standard output.
69.Pp
70If the output file
71.Pa nohup.out
72cannot be created in the current directory,
73.Nm
74attempts to create the file in the user's home directory.
75If the file
76.Pa nohup.out
77cannot be created,
78either in the current directory or the user's home directory,
79.Nm
80will exit without invoking
81.Ar utility ,
82with an exit value as described below.
83.Sh ENVIRONMENT
84.Bl -tag -width Ds
85.It Ev HOME
86User's home directory.
87.El
88.Sh EXIT STATUS
89The
90.Nm
91utility exits with one of the following values:
92.Pp
93.Bl -tag -width Ds -offset indent -compact
94.It 126
95The
96.Ar utility
97was found but could not be invoked.
98.It 127
99The
100.Ar utility
101could not be found or an error occurred in
102.Nm .
103.El
104.Pp
105Otherwise, the exit status of
106.Nm
107shall be that of
108.Ar utility .
109.Sh SEE ALSO
110.Xr csh 1 ,
111.Xr signal 3
112.Sh STANDARDS
113The
114.Nm
115utility is compliant with the
116.St -p1003.1-2008
117specification.
118.Pp
119.Nm
120also exists as a built-in to
121.Xr csh 1 ,
122though with a different syntax.
123