envmgr.sh

#!/usr/bin/env zsh
# -*- coding: utf-8 -*-
# vim: set ai et ts=4 sts=4 sw=4 syntax=zsh:

set -o pipefail

function __ensure_envdir() {
    [[ ! -d "${HOME}/.envmgr.d/" ]] && mkdir -p "${HOME}/.envmgr.d/"
    return 0
}

# Function exit codes:
#  0 - Ok
#  1 - ENVNAME missing
#  2 - Environment file missing
#  3 - Environment file already exists
#  127 - Programmer error

function __load_env() {
    [[ -z "${1}" ]] && return 1 || ENVNAME=${1}
    [[ ! -z "${1}" ]] && ENVNAME=${1}
    [[ -f "${HOME}/.envmgr.d/${ENVNAME}.env" ]] && \
        source "${HOME}/.envmgr.d/${ENVNAME}.env" && \
        $SHELL ; \
        return 0

    return 2
}

function __new_env() {
    [[ -z "${1}" ]] && return 1 || ENVNAME=${1}
    [[ ! -z "${1}" ]] && ENVNAME=${1}
    [[ ! -f "${HOME}/.envmgr.d/${ENVNAME}.env" ]] && \
        touch "${HOME}/.envmgr.d/${ENVNAME}.env" && \
        return 0

    return 3
}

function __list_envs() {
    [[ -d "${HOME}/.envmgr.d" ]] && \
        ls ${HOME}/.envmgr.d/*.env | \
        xargs -n1 basename | \
        cut -d'.' -f1 && \
        return 0

    return 127
}

function __delete_env() {
    [[ -z "${1}" ]] && return 1 || ENVNAME=${1}
    [[ -f "${HOME}/.envmgr.d/${ENVNAME}.env" ]] && \
        rm -v "${HOME}/.envmgr.d/${ENVNAME}.env" && \
        return 0

    return 127
}

function __edit_env() {
    [[ -z "${EDITOR}" ]] && EDITOR="vim"
    [[ ! -z "${1}" ]] && ENVNAME=${1}
    [[ -f "${HOME}/.envmgr.d/${ENVNAME}.env" ]] && \
        $EDITOR "${HOME}/.envmgr.d/${ENVNAME}.env" && \
        return 0

    return 2
}

function __handle_command() {
    COMMAND="${1}"
    shift

    case "${COMMAND}" in
        new)
            ENVNAME="${1}"
            __new_env "${ENVNAME}"
            __handle_retcode $?
            ;;
        delete)
            ENVNAME="${1}"
            __delete_env "${ENVNAME}"
            __handle_retcode $?
            ;;
        edit)
            ENVNAME="${1}"
            __edit_env "${ENVNAME}"
            __handle_retcode $?
            ;;
        load)
            ENVNAME="${1}"
            __load_env "${ENVNAME}"
            __handle_retcode $?
            ;;
        list)
            __list_envs
            __handle_retcode $?
            ;;
        help|*)
            echo "envmgr - a simple shell environment manager"
            echo "  commands:"
            echo "    new [envname]: create a new environment"
            echo "    delete [envname]: delete an environment"
            echo "    edit [envname]: open an environment file in your editor"
            echo "    load [envname]: load an environment"
            echo "    list: show available environments"
            echo
            ;;
    esac
}

function __handle_retcode() {
    [[ -z "${1}" ]] && \
        echo "No return code provided" && \
        return 127

    RETURN_CODE=${1}
    case "${RETURN_CODE}" in
        1)
            echo "Environment name required but not provided"
            ;;
        2)
            echo "Could not find environment file: ${ENVNAME}"
            ;;
        3)
            echo "Environment file already exists: ${ENVNAME}"
            ;;
        127)
            echo "This is probably a bug"
            ;;
    esac

    exit ${RETURN_CODE}
}

__ensure_envdir

COMMAND=$(echo ${1} | tr '[A-Z]' '[a-z]')
[[ $# > 1 ]] && shift

__handle_command "${COMMAND}" "$@"