#!/bin/dash
TO_UPPER=""
TO_LOWER=""
PREFIX=
SUFFIX=
FILTER_VOWELS=""
ARGC=0

usage() {
	cat << EOF
usage: $0 [-luvh] [-p prefix] [-s suffix] [inputs...]

options:
  -l         convert inputs to lowercase
  -u         convert inputs to uppercase
  -v         remove vowels from inputs
  -h         show help
  -p prefix  add \`prefix\` to each line before inputs
  -s suffix  add \`suffix\` to each line after inputs

notes:
  if -l and -u are specified at the same time, the lowercase option will have
  precedence
EOF
  exit $1
}

while getopts dulhp:s:v OPT; do
	[ $OPTIND -gt $ARGC ] && ARGC=$OPTIND
	case $OPT in
		u) TO_UPPER="y" ;;
		l) TO_LOWER="y" ;;
		h) usage 0 ;;
		p) PREFIX=$OPTARG ;;
		s) SUFFIX=$OPTARG ;;
		v) FILTER_VOWELS="y" ;;
		\?|*) usage 1 ;;
	esac
done

[ $(( $# - $ARGC )) -lt 0 ] && echo "please provide some input" && usage 1

shift $(( ARGC - 1 ))

while [ -n "$1" ]; do
	OUT="$1"
	[ -n "$TO_UPPER" ] && OUT="`echo "$OUT" | sed 's/./\U\0/g'`"
	[ -n "$TO_LOWER" ] && OUT="`echo "$OUT" | sed 's/./\L\0/g'`"
	[ -n "$FILTER_VOWELS" ] && OUT="`echo "$OUT" | sed 's/[aeuio]//g'`"
	echo "$PREFIX$OUT$SUFFIX"
	shift
done