/contrib/groff/contrib/eqn2graph/eqn2graph.sh

 1#! /bin/sh
 2#
 3# eqn2graph -- compile EQN equation descriptions to bitmap images
 4#
 5# by Eric S. Raymond <esr@thyrsus.com>, July 2002
 6#
 7# In Unixland, the magic is in knowing what to string together...
 8#
 9# Take an eqn equation on stdin, emit cropped bitmap on stdout.
10# The pic markup should *not* be wrapped in .EQ/.EN, this script will do that.
11# A -U option on the command line enables gpic/groff "unsafe" mode.
12# A -format FOO option changes the image output format to any format
13# supported by convert(1).  All other options are passed to convert(1).
14# The default format is PNG.
15#
16# This is separate from pic2graph because pic processing has some weird
17# clipping effect on the output, mangling equations that are very wide 
18# or deep.  Besides, this tool can supply its own delimiters.
19#
20
21# Requires the groff suite and the ImageMagick tools.  Both are open source.
22# This code is released to the public domain.
23#
24# Here are the assumptions behind the option processing:
25#
26# 1. None of the options of eqn(1) are relevant.
27#
28# 2. Only the -U option of groff(1) is relevant.
29#
30# 3. Many options of convert(1) are potentially relevant, (especially 
31# -density, -interlace, -transparency, -border, and -comment).
32#
33# Thus, we pass -U to groff(1), and everything else to convert(1).
34#
35# $Id: eqn2graph.sh,v 1.5 2005/05/18 07:03:06 wl Exp $
36#
37groff_opts=""
38convert_opts=""
39format="png"
40
41while [ "$1" ]
42do
43    case $1 in
44    -unsafe)
45	groff_opts="-U";;
46    -format)
47	format=$2
48	shift;;
49    -v | --version)
50	echo "GNU eqn2graph (groff) version @VERSION@"
51	exit 0;;
52    --help)
53	echo "usage: eqn2graph [ option ...] < in > out"
54	exit 0;;
55    *)
56	convert_opts="$convert_opts $1";;
57    esac
58    shift
59done
60
61# create temporary directory
62tmp=
63for d in "$GROFF_TMPDIR" "$TMPDIR" "$TMP" "$TEMP" /tmp; do
64    test -z "$d" && continue
65
66    tmp=`(umask 077 && mktemp -d -q "$d/eqn2graph-XXXXXX") 2> /dev/null` \
67    && test -n "$tmp" && test -d "$tmp" \
68    && break
69
70    tmp=$d/eqn2graph$$-$RANDOM
71    (umask 077 && mkdir $tmp) 2> /dev/null && break
72done;
73if test -z "$tmp"; then
74    echo "$0: cannot create temporary directory" >&2
75    { (exit 1); exit 1; }
76fi
77
78trap 'exit_status=$?; rm -rf $tmp && exit $exit_status' 0 2 15 
79
80# Here goes:
81# 1. Add .EQ/.EN.
82# 2. Process through eqn(1) to emit troff markup.
83# 3. Process through groff(1) to emit Postscript.
84# 4. Use convert(1) to crop the Postscript and turn it into a bitmap.
85read equation
86(echo ".EQ"; echo 'delim $$'; echo ".EN"; echo '$'"$equation"'$') | \
87	groff -e $groff_opts -Tps -P-pletter > $tmp/eqn2graph.ps \
88	&& convert -trim -crop 0x0 $convert_opts $tmp/eqn2graph.ps $tmp/eqn2graph.$format \
89	&& cat $tmp/eqn2graph.$format
90
91# End