Improve command description, from jmc, jaredy, and tom, all @openbsd.

usr.bin/nohup/nohup.1

@@ -1,4 +1,4 @@
-.\"	$NetBSD: nohup.1,v 1.12 2003/08/07 11:15:24 agc Exp $
+.\"	$NetBSD: nohup.1,v 1.13 2005/07/14 22:16:39 wiz Exp $
 .\"
 .\" Copyright (c) 1989, 1990, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -32,7 +32,7 @@
 .\"
 .\"	@(#)nohup.1	8.1 (Berkeley) 6/6/93
 .\"
-.Dd June 6, 1993
+.Dd July 15, 2005
 .Dt NOHUP 1
 .Os
 .Sh NAME
@@ -45,19 +45,39 @@
 .Sh DESCRIPTION
 The
 .Nm
-utility invokes
-.Ar command
-with
-its arguments
-and at this time sets the signal
+command allows the specified utility to be protected from termination
+if the user should become logged out
+(for example, due to a modem line or TCP/IP connection being dropped).
+To do this,
+.Nm
+sets the
 .Dv SIGHUP
-to be ignored.
+.Xr signal 3
+.Pq Dq terminal line hangup
+to be ignored,
+then executes
+.Ar utility
+along with any arguments.
+.Pp
 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.
+If the output file
+.Pa nohup.out
+cannot be created in the current directory,
+.Nm
+attempts to create the file in the user's home directory.
+If the file
+.Pa nohup.out
+cannot be created,
+either in the current directory or the user's home directory,
+.Nm
+will exit without invoking
+.Ar utility ,
+with an exit value as described below.
 .Sh EXIT STATUS
 The
 .Nm
@@ -83,13 +103,7 @@ The following variable is used 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.
+User's home directory.
 .El
 .Sh SEE ALSO
 .Xr signal 3