make-git-info

#!/bin/sh

desc=$(git describe --tags)

if [ "$desc" = "" ]
then
    echo "#undef GIT_VERSION" > new-git-info.h
else
    auth=$(git log -n 1 "--pretty=format:%an <%ae> %aD")

    echo "#define GIT_VERSION      "'"'"$desc"'"' >new-git-info.h
    echo "#define GIT_AUTHOR_DATE  "'"'"$auth"'"' >>new-git-info.h
fi

# move-if-different
if diff new-git-info.h git-info.h >/dev/null 2>&1
then
    rm new-git-info.h
else
    mv new-git-info.h git-info.h
fi