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 92