git-changebar

#!/bin/sh
#
# git-changebar
#
# Will add changebars to a LaTeX file stored in git based on the diff to a past
# treeish or branch in the repository
#
# Copyright (c) Matthew Johnson <src@matthew.ath.cx> 2007
#
# 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 version 2.  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, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
# USA.



if [ -z "$1" ] || [ -z "$2" ] || [ "--help" = "$1" ]; then
   echo "Syntax: $0 <treeish> <file...>"
   exit 1
fi

REV="$1"
shift

while [ -n "$1" ]
do
   if grep 'tex[[:space:]]*$' >/dev/null <<@
$1
@
   then
      FILE="$1"
      OUT="${FILE%.tex}.diff.tex"
      cp "$FILE" "$OUT"

      docstart=$(grep -n 'begin{document}' "$FILE" | cut -d: -f1)

      for i in $(GIT_DIFF_OPTS=-u0 git diff "$REV" "$FILE" |
                sed -n '/^@@/s/@@ -[0-9,]* +\([0-9,]*\).*/\1/p')
      do
         start=$(cut -d, -f1 <<@
$i
@
)
         if [ "$start" -gt "$docstart" ]
         then
            if grep ',' >/dev/null <<@
$i
@
            then
               diff=$(cut -d, -f2 <<@
$i
@
)
            else
               diff=0
            fi
            end=$(( $start + $diff ))
            sed -i "${start}s/^/\\\\cbstart{} /" "$OUT"
            sed -i "${end}s/$/ \\\\cbend{}/" "$OUT"
         fi
      done

      sed -i '2i\\\\usepackage[dvips]{changebar}\n' "$OUT"
      echo "Changebars added to $OUT"
   else
      echo "$1 is not a TeX file"
   fi

   shift
done