Update hook for git which prevents files from having their line endings set to CRLF.

update

#!/bin/sh
# AUTHOR: Paul Schoenfelder
#
# This post-receive hook validates that committed files use proper (LF) line endings.

verify_lf()
{
    echo "Validating line endings..."
    oldrev=$(git rev-parse $1)
    newrev=$(git rev-parse $2)
    refname="$3"

    invalid_lines=$(git diff --numstat --name-only --diff-filter=AMR $newrev..$oldrev | 
        sed -E 's/([0-9a-zA-Z\\\/_-~]+)/'$newrev':\1/' |
        xargs git cat-file blob |
        grep -Iu "
" | 
        wc -l)

    if [ "$invalid_lines" != "0" ]; then
        cat <<EOF
Error: Attempt to push files with invalid CRLF line-endings.

Please ensure you have the following in your .git/config:

[core]
    autocrlf = input

You will need to update these files to use Unix-style line-endings (LF).
EOF
        exit 1
    fi
    echo "Line endings good!"
}

# Allow dual mode: run from the command line or if no arguments
# are given, then run as a hook script
if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
    echo "ARGS:" $1 $2 $3
    verify_lf $2 $3 $1
else
    while read refname oldrev newrev
    do
        verify_lf $oldrev $newrev $refname
    done
fi