Query failed: connection to localhost:9312 failed (errno=111, msg=Connection refused). File type/kind - Genius Bar Discussions on AppleInsider Forums Toggle navigation All Forums Recent Posts Sign In File type/kind longhorn Posted: August 7, 2003 12:51PM in Genius Bar edited January 2014 anyone know the four letter extension assigned to classic and OSX apps? i'm trying to find a way to exclude them from a backup set. Comments Reply 1 of 1 vortex Posts: 18member August 9, 2003 12:19AM Well, I'm pretty sure that Mac OS X applications are actually folders (packages, to be specific) with the extension ".app". As for Classic apps, I'm not sure ? I don't have OS X installed on my system yet.An easy way to see what the file extensions are is with the terminal. To see OS X app extensions, type:ls -a /ApplicationsTo see Classic app extensions (if they even exist), type:ls -a "/Applications (Mac OS 9)"Hope this helps! Sign In or Register to comment.