Slugify strings in bash with awk

slugify

#!/usr/bin/env bash
#
# Accepts an input string and slugifies it by replacing anything non-alphanumeric with a dash.
#
# Example;
#
#   $ slugify "foo bar hello/world"
#   > foo-bar-hello-world
#
#   $ echo "foo bar hello/world" | slugify
#   > foo-bar-hello-world
#
args=$*

[[ -p /dev/stdin ]] && {
	mapfile -t
	set -- "${MAPFILE[@]}"
	set -- "$@" "$args"
}

echo -n "$*" | awk -f <(cat - <<-'AWK'
	{
		gsub("^[ \t-]+", "");
		gsub("[ \t-]+$", "");
		gsub("[^a-zA-Z0-9]+", "-");
		print tolower($0)
	}
AWK
)