pre-commit hook to run phpcs

.git_hooks_pre-commit

#!/bin/sh

PRE_COMMIT="$(cat <<'EOF'
#!/bin/sh

PROJECT=`php -r "echo dirname(dirname(dirname(realpath('$0'))));"`
STAGED_FILES_CMD=`git diff --cached --name-only --diff-filter=ACMR HEAD | grep \.php`

# Determine if a file list is passed
if [ "$#" -eq 1 ]
then
    oIFS=$IFS
    IFS='
    '
    SFILES="$1"
    IFS=$oIFS
fi
SFILES=${SFILES:-$STAGED_FILES_CMD}

echo "Checking PHP Lint..."
for FILE in $SFILES
do
    php -l -d display_errors=0 $PROJECT/$FILE
    if [ $? != 0 ]
    then
        echo "Fix the error before commit."
        exit 1
    fi
    FILES="$FILES $PROJECT/$FILE"
done

if [ "$FILES" != "" ]
then
    echo "Running Code Sniffer..."
    ./bin/phpcs --standard=PSR2 --encoding=utf-8 -n -p $FILES
    if [ $? != 0 ]
    then
        echo "Fix the error before commit."
        exit 1
    fi
fi

exit $?

EOF
)"



echo "$PRE_COMMIT" > .git/hooks/pre-commit
chmod +x .git/hooks/pre-commit

You can save this as a .sh file and set this as a composer post-install script; that will enforce PSR-2 and PHP Lint for everyone who tries to commit.

To temporarily disable it, you can chmod -x .git/hooks/pre-commit, and then put +x back to re-enable it.