piando

#!/bin/bash
set -u
set -e

search() {
    for obj in "$1"/*; do
        [[ "$obj" == *$2 ]] && [[ "$3" == "NO" ]] && [[ ! -d "$obj" ]] && printf '%s\n' "$obj"
        [[ "$obj" == *$2 ]] && [[ "$3" == "YES" ]] && [[ -d "$obj" ]] && printf '%s\n' "$obj"
    done
}

recursive_search() {
    shopt -s globstar
    for obj in "$1"/**/*; do
        [[ "$obj" == *$2 ]] && [[ "$3" == "NO" ]] && [[ ! -d "$obj" ]] && printf '%s\n' "$obj"
        [[ "$obj" == *$2 ]] && [[ "$3" == "YES" ]] && [[ -d "$obj" ]] && printf '%s\n' "$obj"
    done
    shopt -u globstar
}


RECURSIVE_SEARCH=NO
FOLDERS=NO
EXTENSION=""
DIR="."
main() {
	for i in "$@"; do
	case $i in
        -e|--extension)
        EXTENSION="$2"
        shift
        shift
        ;;
		-f|--folders)
		FOLDERS=YES
		shift
        ;;
		-r|--recursive)
		RECURSIVE_SEARCH=YES
		shift
		;;
		-d|--directory)
		DIR="$2"
		shift
        shift
		;;
        *)    
		;;
	esac
	done
    [ ! -d "$DIR" ] && die "directory doesn't exist"
    if [[ "$RECURSIVE_SEARCH" == "YES" ]]; then
        recursive_search "$DIR" "$EXTENSION" "$FOLDERS" | shuf
    else
        search "$DIR" "$EXTENSION" "$FOLDERS" | shuf
    fi
}

die() {
    printf 'error: %s.\n' "$1" >&2
    exit 1
}

main "$@"