find duplicate strings file entries (duplicate keys! the value can differ)

duplicateStringsKeys.sh

	#!/bin/bash

	FILENAME="Localizable.strings"
	DUPES=`cut -d' ' -f1 "$FILENAME" | sort | uniq -d`

	while read -r line; do
	    echo "error: $line used multiple times -"
	done <<< "$DUPES"

xcodeBuildphase

	#!/bin/bash

	c=`expr $SCRIPT_INPUT_FILE_COUNT - 1`
	for i in $(seq 0 $c)
		do

		var="SCRIPT_INPUT_FILE_$i"
		FILENAME=${!var}

		DUPES=`cut -d' ' -f1 "$FILENAME" | sort | uniq -d`

		while read -r line; do
			if [[ $line == "\""* ]] ;
			then
				echo "warning: $line used multiple times -"
			fi
		done <<< "$DUPES"
	done

See http://stackoverflow.com/questions/24124530/how-to-find-duplicates-in-localizable-strings-files-automatically/