Generate random filenames using an adjective and a noun from the WordNet dictionaries

gen_random_filename.bash

# Bash function gen_random_filename
# Description: Generates random file names
# Requires shuf (brew install coreutils)
# Requires a list of adjectives and nouns (1 per line)

gen_random_filename() {
	local adjs=~/words/adjectives.txt
	local nouns=~/words/nouns.txt
	local adj noun title starts_with_1 starts_with_2 counter

	# process arguments for "starts_with" variables
	counter=1
	while [[ -n $1 ]]; do
		# only accept single letter (a-z) arguments
		if [[ $1 =~ ^[a-zA-Z]$ ]]; then
			eval starts_with_$counter="$1"
			counter=$[counter + 1]
		fi
		shift
	done

	# if starts_with_1 has a value and starts_with_2 doesn't, duplicate
	[[ -z $starts_with_2 && -n $starts_with_1 ]] && starts_with_2=$starts_with_1

	# if shuf is installed...
	if [[ $(which shuf) ]]; then
		# grep for starts_with value and pick random result
		# if starts_with is empty, grep will return all entries
		adj=`grep --color=never -e "^$starts_with_1" $adjs | shuf -n 1`
		noun=`grep --color=never -e "^$starts_with_2" $nouns | shuf -n 1`
		# concatenate adjective and noun
		title=`echo ${adj}_${noun}`
	# otherwise, error
	else
		cat <<-EOS
		$FUNCNAME requires the utility shuf to generate random names.
		Use homebrew to install "coreutils," which includes shuf.
		EOS
		return
	fi
	echo $title
}