<h2>Edit File: pamstretch-gen</h2><form method="post"><textarea name="content" rows="20" cols="80">#!/bin/sh
#
# pamstretch-gen - a shell script which acts a little like a general
# form of pamstretch, by scaling up with pamstretch then scaling
# down with pamscale.
#
# it also copes with N&lt;1, but then it just uses pamscale. :-)
#
# Formerly named &#039;pnminterp-gen&#039; and &#039;pnmstretch-gen&#039;.
#
# Copyright (C) 1998,2000 Russell Marks.
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
# 
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# 

if [ &quot;$1&quot; = &quot;--version&quot; -o &quot;$1&quot; = &quot;-version&quot; ]; then
        pamstretch --version; exit $?;
fi

if [ &quot;$1&quot; = &quot;&quot; ]; then
  echo &#039;usage: pamstretch-gen N [pnmfile]&#039;
  exit 1
fi

tempfile=$(mktemp /tmp/pnmig.XXXXXXXX) ||
    ( echo &quot;Could not create temporary file. Exiting.&quot; 1&gt;&amp;2; exit 1; ) 
trap &#039;rm -rf $tempdir&#039; 0 1 3 15

if ! cat $2 &gt;$tempfile 2&gt;/dev/null; then
  echo &#039;pamstretch-gen: error reading file&#039; 1&gt;&amp;2
  exit 1
fi

if ! pnmfile $tempfile 1&gt;/dev/null 2&gt;/dev/null; then
  echo &#039;Not valid pnm input&#039;
  exit 1
fi

# we use the width as indication of how much to scale; width and
# height are being scaled equally, so this should be ok.
width=`pnmfile $tempfile 2&gt;/dev/null|cut -d &quot; &quot; -f 3`

if [ &quot;$width&quot; = &quot;&quot; ]; then
  echo &#039;pamstretch-gen: not a PNM file&#039; 1&gt;&amp;2
  exit 1
fi

# should really use dc for maths, but awk is less painful :-)
target_width=`awk &#039;BEGIN{printf(&quot;%d&quot;,&#039;0.5+&quot;$width&quot;*&quot;$1&quot;&#039;)}&#039;`

# work out how far we have to scale it up with pamstretch so that the
# new width is &gt;= the target width.
int_scale=`awk &#039;
BEGIN {
int_scale=1;int_width=&#039;&quot;$width&quot;&#039;
while(int_width&lt;&#039;&quot;$target_width&quot;&#039;)
  {
  int_scale++
  int_width+=&#039;&quot;$width&quot;&#039;
  }
print int_scale
}&#039;`

if [ &quot;$int_scale&quot; -eq 1 ]; then
  pamscale &quot;$1&quot; $tempfile
else
  pamstretch &quot;$int_scale&quot; $tempfile | pnmscale -xsi &quot;$target_width&quot;
fi
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