Composer bootstrap bash script

composer.sh

#!/usr/bin/env bash
# Composer bootstrap script
# https://getcomposer.org/
# https://gist.github.com/chervand/bb707efaa1d244b1ed38

function trace () {
    echo "... ${@}" && "$@"
}

_source="$(readlink -f ${BASH_SOURCE[0]})"
_scriptPath="$(dirname ${_source})"

trace cd ${_scriptPath}

if [ -x "$(command -v composer)" ]; then
   trace composer $@
else
    if [ ! -f composer.phar ]; then
        curl -sS https://getcomposer.org/installer | php
    fi
    trace php composer.phar $@
fi