make ffmpeg not read from stdin and check output of ffmpeg

fix_unknown_album_and_artist_flac_file.sh

@@ -15,10 +15,14 @@ function fix_flac_file()
 
 	echo "running command ffmpeg -i $1 -c:a flac -map_metadata 0 fixed.flac"
 
-	ffmpeg -i "$1" -c:a flac -map_metadata 0 "fixed.flac"
-
-	echo "moving fixed.flac to $1"
-	mv "fixed.flac" "$1"
+	if ffmpeg -nostdin -i "$1" -c:a flac -map_metadata 0 fixed.flac
+	then
+		echo "Moving fixed.flac to $1"
+		mv fixed.flac "$1"
+	else
+		echo "Failed to process $1" >&2
+		rm -f fixed.flac
+	fi
 }
 
 function print_help()
@@ -51,7 +55,8 @@ else
 	if [ "$1" = "-l" ]
 	then
 		echo "Looping through $2"
-		while read flacfile; do
+		# Use IFS= and -r with read so backslashes and leading/trailing whitespace are preserved
+		while IFS= read -r flacfile; do
 			echo "Processing line $flacfile"
 			fix_flac_file "$flacfile"
 		done < "$2"