#!/bin/sh
# slugify — convert text to url-safe slugs

if [ -z "$1" ]; then
    read -r input
else
    input="$*"
fi

printf '%s' "$input" \
    | tr '[:upper:]' '[:lower:]' \
    | sed 's/[^a-z0-9 _-]//g' \
    | tr ' _' '--' \
    | sed 's/--*/-/g; s/^-//; s/-$//'