Print all or an index of $GOPATH

bashrc_snippet.sh

# Without an argument, prints the current gopath
# With a integer argument, prints the directory at the index of a multi-directory GOPATH

gopath ()
{ 
    if [ -z "$GOPATH" ]; then
        echo "GOPATH not set...";
        exit 1;
    fi;
    local gopath="${GOPATH}";
    local max_index="$(awk -F: '{ print NF }' <<< \"${gopath}\")";
    local re="^[0-9]+$";
    if [[ "${1}" =~ ${re} ]]; then
        local index="${1}";
    else
        printf "${gopath}\n";
        return;
    fi;
    ((index++));
    if [ "${index}" -gt "${max_index}" ]; then
        printf "ERROR: index out of range\n";
    fi;
    awk -v ind=${index} '{split($0, gopaths, ":"); print gopaths[ind]}' <<< "${gopath}"
}