invirtualenv

#! /bin/sh
#
PROG="$(basename $0)"

usage () {
cat <<EOF
Usage: $PROG DIR CMD [ARG ...]

Run CMD (with its optional ARGs) within the Python virtual env located
at DIR.

Options:

  --help, -h  Print this help text.

EOF
}


## helper functions
die () {
  rc="$1"
  shift
  (echo -n "$PROG: ERROR: ";
      if [ $# -gt 0 ]; then echo "$@"; else cat; fi) 1>&2
  exit $rc
}

warn () {
  (echo -n "$PROG: WARNING: ";
      if [ $# -gt 0 ]; then echo "$@"; else cat; fi) 1>&2
}

have_command () {
  type "$1" >/dev/null 2>/dev/null
}

require_command () {
  if ! have_command "$1"; then
    die 1 "Could not find required command '$1' in system PATH. Aborting."
  fi
}


## parse command-line

short_opts='hx'
long_opts='help,debug'

if [ "x$(getopt -T)" != 'x--' ]; then
    # GNU getopt
    args=$(getopt --name "$PROG" --shell sh -l "$long_opts" -o "$short_opts" -- "$@")
    if [ $? -ne 0 ]; then
        die 1 "Type '$PROG --help' to get usage information."
    fi
    # use 'eval' to remove getopt quoting
    eval set -- $args
else
    # old-style getopt, use compatibility syntax
    args=$(getopt "$short_opts" "$@")
    if [ $? -ne 0 ]; then
        die 1 "Type '$PROG --help' to get usage information."
    fi
    set -- $args
fi

while [ $# -gt 0 ]; do
    case "$1" in
        --debug|-x) set -x ;;
        --help|-h) usage; exit 0 ;;
        --) shift; break ;;
    esac
    shift
done

if [ "$#" -lt 1 ]; then
    die 1 "Usage: ${PROG} DIR CMD [ARG ...]"
fi


## main

ve="$1"; shift
if ! [ -d "$ve" ]; then
    die 2 "Path '$ve' is not a directory!"
fi
if ! [ -r "$ve"/bin/activate ]; then
    die 2 "No 'bin/activate' script found in directory '$ve'"
fi

(. "$ve"/bin/activate; "$@")