mburr / bash parse-fname

parse-fname

#!/bin/bash
#
# find latest version here: https://gist.github.com/mburr/eac741ea7425fbea837f
#
# adapted from http://stackoverflow.com/questions/965053/extract-filename-and-extension-in-bash

function parse-fname()
{
	# parse a filename into path, base file (without extension), and extension
	# Which of these compenents is returned is determined by the specified option:
	#
	#	-p - returns path (including trailing '/')
	#	-f - returns base filename without extension	(this is the default)
	#	-x - returns extension (including the period)
	#	-e - synonym for -x
	#
	# Examples:
	#
	#		parse-fname    /some/path/test.ext	--> "test"
	#		parse-fname -p /some/path/test.ext	--> "/some/path/"
	#		parse-fname -f /some/path/test.ext	--> "test"
	#		parse-fname -x /some/path/test.ext	--> ".ext"
	#
	#	a filename that starts with a '.' is considered to have no extension, so:
	#
	#		parse-fname    ~/.bash_profile			--> ".bash_profile"
	#		parse-fname -x ~/.bash_profile			--> ""
	#
	#	Note: no canonicalization of the path or checking for existance of the file
	#		is done - this is entirely parsing based on the string value.
	#		

	local opt="-f"		# default to outputing the base filename
	local fullfile=""
	local arg

	for arg; do
		case "$arg" in
			-f|-e|-x|-p)
				opt="$arg"
				;;
			*)
				fullfile="$arg"
				break
				;;
		esac
	done

	local filename=$(basename "$fullfile")
	local path="${fullfile%$filename}"
	local extension=$([[ "$filename" = *.* ]] && echo ".${filename##*.}" || echo '')
	
	# fix up the case where the filename is empty becuase the 
	# the filename looks like an extension
	filename="${filename%.*}"
	if [[ -z "$filename" ]]; then
		filename="$extension"
		extension=""
	fi

	case "$opt" in
		-f)
			echo "$filename"
			;;
		-e|-x)
			echo "$extension"
			;;
		-p)
			echo "$path"
			;;
	esac
}