cliv: Command-LIne wrapper to execute different Versions of binaries in different directories using different environment variables

cliv

#!/usr/bin/env sh
# cliv - Execute commands using a specific .env and directory
set -eu

_err () { printf "%s\n" "$0: Error: $*" ; exit 1 ; }

HOME="${HOME:-$(getent passwd $(id -u) | cut -d : -f 6)}"
[ -d "$HOME/.cliv" ] || mkdir -p "$HOME/.cliv"

if [ $# -lt 1 ] || [ "$1" = "-h" ] ; then
  printf "%s\n" "
Usage: $0 [OPTS]
       $0 [-i] VERSION [CMD [ARGS ..]]\n
Opts:
        -l              List versions
        -h              This screen
        -n              Create a new $HOME/.cliv/VERSION
        -i              Clear current environment
"
  exit 1
fi


if [ "$1" = "-i" ] ; then
  shift
  exec env -i "$0" "$@"

elif [ "$1" = "-l" ] ; then
  for d in "$HOME/.cliv/"* ; do [ -d "$d" ] && basename "$d" ; done

elif  [ "$1" = "-n" ] ; then
  vers="$2"; shift 2
  [ -d "$HOME/.cliv/$vers" ] && _err "Version '$HOME/.cliv/$vers' already exists"
  mkdir -p "$HOME/.cliv/$vers/bin"
  echo "PATH=$HOME/.cliv/$vers/bin:$PATH" > "$HOME/.cliv/$vers/.env"

elif [ $# -ge 1 ] ; then
  vers="$1" ; shift
  [ -d "$HOME/.cliv/$vers" ] || _err "No version '$HOME/.cliv/$vers' found"
  set -a ; . "$HOME/.cliv/$vers/.env"
  exec env "$@"
fi