nix/home/program/bash/module/Util.nix

{ ... }: {
	text = ''
		# Get the number of avaialble cores (threads).
		function _core_count() {
			cat /proc/cpuinfo | grep ^processor | wc -l
		}

		# Get the number of available memory (in mebibytes).
		function _mem_free() {
			free -m | sed -n -e '2p' | awk '{print $7}'
		}

		# Function-wrapper to iterate with specified function with provided files.
		# By default Iterates on all non-hidden files and directories.
		# List of variables available to FUNCTION: target - current file, count - current item index, total - sum of targets, failed - count of previously failed items, skipped - count of skipped files, status - status line (not recommended to use).
		# Usage: _iterate_targets <FUNCTION> [FILES]
		function _iterate_targets() {
			local IFS=$'\n'
			local foo="''${1}"
			local targets=("''${@:2}")
			local total=''${#targets[@]}
			local count=0
			local failed=0
			local skipped=0
			local code=0

			# set dafult value to target all supported archives.
			if [[ "''${targets}" = "" ]]; then
				_error "No targets provided."
				return 1
			fi

			# iterate each target.
			for target in "''${targets[@]}"; do
				# increment counter.
				((count++))

				# status info.
				local status="[''${count}/''${total}] ''${target}"
				_info "''${status}"

				# Call function.
		''${foo} "''${target}"

				# Show error.
				if [[ ''${?} != 0 ]]; then
					((failed++))
					_error "''${status}: Failed."
				fi

				# Add newline if not the last one.
				[[ "''${count}" = "''${total}" ]] || _info
			done

			# Show skipped.
			if [[ ''${skipped} != 0 ]]; then
				_warn
				_warn "''${color_byellow}Skipped: ''${skipped}.''${color_default}"
			fi

			# Show error.
			if [[ ''${failed} != 0 ]]; then
				[[ "''${skipped}" = 0 ]] && _error
				_error "''${color_bred}Failed: ''${failed}.''${color_default}"
				false
			fi
		}

		# Skip current iteration.
		# Usage: _iterate_skip [MESSAGE]
		function _iterate_skip() {
			((skipped++))

			[[ "''${*}" != "" ]] && _warn "''${color_byellow}''${*}''${color_default}"
		}

		# Report an error.
		# Always returns code 1.
		# Usage: _error <MESSAGE>
		function _error() {
			>&2 echo -e "''${color_bred}''${*}''${color_default}"
			return 1
		}

		# Report a warning.
		# Usage: _warn <MESSAGE>
		function _warn() {
			>&2 echo -e "''${color_byellow}''${*}''${color_default}"
		}

		# Report a debug.
		# Usage: _debug <MESSAGE>
		function _debug() {
			>&2 echo -e "''${color_bwhite}''${*}''${color_default}"
		}

		# Report an info.
		# Usage: _info <MESSAGE>
		function _info() {
			>&2 echo -e "''${color_bwhite}''${*}''${color_default}"
		}

		# Check if array contains an element (strict).
		# Usage: _contains <ELEMENT> <ARRAY>
		function _contains() {
			local IFS=$'\n'
			local target="''${1}"
			local array="''${@:2}"

			if [[ "''${target}" = "" ]] || [[ "''${array}" = "" ]]; then
				help _contains
				return 2
			fi

			for item in ''${array[@]}; do
				[[ "''${item}" = "''${target}" ]] && return 0
			done

			return 1
		}

		# Find an index of an element in array.
		# Usage: _index_of <ELEMENT> <ARRAY>
		function _index_of() {
			local element="''${1}"
			local array="''${@:2}"
			local index=0

			for item in ''${array[@]}; do
				[[ "''${item}" = "''${element}" ]] && break
				((index++))
			done

			echo "''${index}"
		}

		# Check if inside Tmux.
		function _is_tmux() {
			[[ "''${TERM_PROGRAM}" = "tmux" ]]
		}

		# Check if root.
		function _is_root() {
			[[ "''${UID}" = 0 ]]
		}

		# Ring a bell.
		function _bell() {
			echo -e '\a'
		}

		# Get users.
		function _get_users() {
			local users=("voronind" "dasha")
			echo ''${users[@]}
		}
	'';
}