[VE.sh] virtualenv wrapper in bash #virtualenv #shell

ve.sh

# -*- mode: sh -*-
# vim: syn=sh

# check to make sure virtualenv installed
if ! command which -s virtualenv; then
    >&2 echo "You don't have virtualenv installed in your path. To install it:"
    >&2 echo "pip install virtualenv"
    return 1
fi

function ve {
    function _usage {
        echo '
usage:  ve [-h]
        ve [-d ROOT] command [ENV]'
    }

    function _help {
        echo "ve - a bash wrapper for managing Python virtual environments"
        _usage
        echo '
commands:
    mk, mkenv       make a virtual environment
    sw, swenv       switch to a virtual environment
    del, rm, rmenv  delete a virtual environment
    ls, lsenv       list your virtual environments

positional arguments:
    ENV             the name of a virtual env, defaults to the name of the
                        current working directory

optional arguments:
    -h, --help              print this help message
    -d DIR, --dir DIR       directory where virtual envs are stored;
                            overrides VE_ROOT if set [default: ~/.virtualenv]

environment variables:
    VE_ROOT              directory where virtual envs are stored

DO NOT DO:
    ve mkenv ./
    ve sw ./

TO USE: put something like the following in your .bashrc or .bash_profile:

    [ -f ~/some/path/ve.sh ] && . ~/some/path/ve.sh

NOTE: Each virtual environment within a given root virtual env directory must
have a unique name. Virtual environment names can be arbitrary but it is best
to name them after project directories so that way you can just issue the
command "ve sw" from the project root'
    }

    if [ $# -eq 0 ]; then
        _help
        return
    fi

    local root="$VE_ROOT"
    case "$1" in
        -d|--dir )
            root="$2"
            shift
            shift;;
    esac

    # target is what the name of the virtual environment will be
    local target
    target="$(basename "${2:-$(pwd)}")"

    # allow user to use environment variable to set VE_ROOT directory and default to
    # ~/.virtualenv
    [ -z "$root" ] && root="$HOME/.virtualenv"


    # make root directory if it does not exist, exit on failure
    function _mkroot {
        if [ ! -d "$root" ]; then
            echo "Creating root directory: $root"
            if ! mkdir -p -- "$root" 2>/dev/null; then
                echo "Could not create root directory."
                return 2
            fi
        fi
    }


    # the full path to the virtual environment
    local dir="$root/$target"

    # make a virtual environment if directory does not exist
    function mkenv {
        _mkroot
        if [ ! -d "$dir" ]; then
            virtualenv "$dir"
        else
            >&2 echo "That virtual environment already exists. To switch to it:"
            >&2 echo "ve sw $target"
        fi
    }

    # switch to virtual environment by sourcing activate file of said environment if
    # it exists
    function swenv {
        if [ -f "$dir/bin/activate" ]; then
            . "$dir/bin/activate"
        else
            >&2 echo "That virtual environment does not exist. To make it:"
            >&2 echo "ve mk $target"
        fi
    }

    # deactivate and delete a virtual environment if it exists
    function rmenv {
        if [ -d "$dir" ]; then
            if [ "$(command which pip)" == "$dir/bin/pip" ]; then
                deactivate
            fi
            command rm -rf "$dir"
        else
            >&2 echo "That virtual environment does not exist."
        fi
    }

    function lsenv {
        command ls -1 "$root"
    }

    # main program
    case "$1" in
        mk|mkenv )
            mkenv "$dir";;

        sw|swenv )
            swenv "$dir";;

        del|rm|rmenv )
            rmenv "$dir";;

        ls|lsenv )
            lsenv;;

        -h|--help )
            _help;;

        * )
            >&2 echo "invalid argument: $1"
            _usage;;
    esac
}

# TODO:
# assert args valid before making a root directory, BUG-M-MH
# handle paths as arguments properly e.g. ./, BUG-ML-M: POSIX
# improve lsenv to do a `pip list` for a venv or list bin, FTR-M-MH