Canonical shell argument parsing.

argparse.zsh

#!/usr/bin/env zsh

# Print usage information if there are no arguments on the command line.
[ "$#" = "0" ] && 
  echo 'Usage: via-ssh.sh [ -v ] [ -d ] [USER@]SERVER[:PORT]' && exit 1

# Process the command line parameters.
while [ "$#" != '0' ] ; do
  case "$1" in
    -v) VERBOSE=1 ; shift ;;
    -d) DNS=1 ; shift ;;
     *) SSH_PORT=${1##*:}
        SSH_USER_SERVER=${1%%:*}
        [ "$SSH_USER_SERVER" = "$SSH_PORT" ] && SSH_PORT=22 
        shift ;;
  esac
done