#!/bin/sh

set -eu

case "$#" in
    0) src="$(cat)";;
    1) src="$1";;
    *)
        echo "Usage: shquote [SOMETHING]" 1>&2
        exit 2
        ;;
esac

printf %s\\n "$src" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/'/"