.\"                                      Hey, EMACS: -*- nroff -*-
.TH YEXPAND 1 "Mar 12, 2008"
.\" Please adjust this date whenever revising the manpage.
.\"
.SH NAME
yexpand \- tool to expand environment variables in Nypatchy cradles
.SH SYNOPSIS
.B yexpand
.IR inputfile " [ " outputfile " ] "
.SH DESCRIPTION
.PP
\fByexpand\fP is a very simple script to expand environment variables in
a text file to their current values in the shell environment.
It was written to be used with \fBnypatchy\fP cradles.  It is recommended
you not try to use it for any other purposes (note BUGS below).
.SH USAGE
\fByexpand\fP takes \fIinputfile\fP as input, replaces all instances of shell
variables (in the form $VARIABLE or ${VARIABLE}) with their current values in
the environment, and saves the result to \fIoutputfile\fP.  Undefined variables
are replaced with the empty string.  If \fIoutputfile\fP
is not given, the result
is instead saved to the current directory as a file of the same name as
\fIinputfile\fP.  Thus an input file in the current directory will be
overwritten.
.SH BUGS
This script is very simple\-minded.  Since it basically just echos its input
file as a here\-doc, it will attempt to perform all types of shell
substitution (command substitution, etc.) as well as variable substitution.
Hence it is likely to fail on anything except the very simplest text files.
.PP
Additionally, this script creates a temporary file.  The file is created
in the current directory, so there should not be security implications.
However, any existing file named \fIfile\fP.yexp (where \fIfile\fP is the
basename of \fIinputfile\fP) in the current directory will be overwritten
and then deleted.
.SH SEE ALSO
.BR fcasplit "(1), " nycheck "(1), " nydiff "(1), " nyindex "(1), "
.BR nylist "(1), " nymerge "(1), " nypatchy "(1), "
.BR nyshell "(1), " nysynopt "(1), " nytidy (1)
.PP
The reference manual for the Nypatchy suite of programs is available
in compressed PostScript format at the following URL:
.br
.I http://wwwasdoc.web.cern.ch/wwwasdoc/psdir/p5refman.ps.gz
.SH AUTHOR
This manual page was written by Kevin McCarty <kmccarty@debian.org>
for the Debian GNU/Linux system (but may be used by others).  It is
licensed under the GNU General Public License, version 2 or later (at your
choice).
.SH COPYRIGHT
Copyright (C) Kevin B. McCarty, 2008.