Detecting file permission changes' in a git repo

When you change some file permissions, git detects it and marks it as changed. Now, imagine you want to revert some file permissions in a git system.

git diff --summary

gives you

mode change 100644 => 100755 Zend/Crypt/DiffieHellman.php

but does not inform you if the content has also changed (AFAIK)

You can output the names of the files that have changes (+++ / ---) and also permission changes:

git diff --summary |grep 'mode change ' | awk '{print $6}' | \
while read file_; do \
    diffed=`git diff $file_|egrep '\+\+\+|---'|wc -l`;
    if test 0 -ne $diffed; then
        echo $file_;
    fi;
 done

You can decide to commit those files first and then the commit/revert the rest, as there are no changes left.