git PEP8 pre-commit hook

pre-commit

# put this in your .git/hooks/pre-commit
# `pip install pep8` before use
# THIS SHOULD BE EXECUTABLE

exec 1>&2 # redirect all output to error output

FILES_HAVING_ERROR=0 # counting files having error
for FILE in $(git diff --cached --name-only) # only check modified & staged files
do
    if [ ${FILE: -3} == ".py" ]; then
        pep8 --show-source --show-pep8 --ignore=E501 $FILE # ignoring E501 which is max-line-length=80
        if [ $? -ne 0 ]; then # $FILE failed to pass PEP8 check
            FILES_HAVING_ERROR=$(($FILES_HAVING_ERROR + 1)); # counting files having error
        fi
    fi
done

# colors for output
WHITE='\033[1;37m'
RED='\033[1;31m'
GREEN='\033[1;32m'
NC='\033[0m'

# PEP8:fail
if [ $FILES_HAVING_ERROR -ne 0 ]; then
    echo "${WHITE}PEP8${NC}:${RED}FAIL${NC}"
    exit 1
fi

# PEP8:PASS
echo "${WHITE}PEP8${NC}:${GREEN}PASS${NC}"
exit 0