function _source_file_if_exists() {
	if [ -r "$1" ]; then
		test -n "${DEBUG_BASHRC}" && echo "-- Sourcing file $1"
		source "$1"
	fi
}

function _source_dir_files() {
	if [ -d "$1" ]; then
		test -n "${DEBUG_BASHRC}" && echo "-- Sourcing files in directory $1"

		# Safe loops for empty dirs
		shopt -s nullglob

		for file in "$1"/*; do
			if [ -e "${file}" ]; then
				test -n "${DEBUG_BASHRC}" && echo "    * sourcing file ${file}"
				source "${file}"
			fi
		done

		# Restore option nullglob to normal
		shopt -u nullglob
	fi
}

# Source : https://superuser.com/questions/39751/add-directory-to-path-if-its-not-already-there
_path_append() {
	if [ -d "$1" ] && [[ ":${PATH}:" != *":$1:"* ]]; then
		PATH="${PATH:+"${PATH}:"}$1"
	fi
}

_path_prepend() {
	if [ -d "$1" ] && [[ ":${PATH}:" != *":$1:"* ]]; then
		PATH="$1${PATH:+":${PATH}"}"
	fi
}

_prompt_command_add() {
	if [ -n "$1" ] && [[ ":${PROMPT_COMMAND}:" != *":$1:"* ]]; then
		PROMPT_COMMAND="${PROMPT_COMMAND:+"${PROMPT_COMMAND};"}$1"
	fi
}