How does one properly lay out a standalone system service in Xcode? - objective-c

Question

I've recently become interested in writing some system services for OS X but since I have no application to advertise the services under I must resort to writing standalone system services. Apple's documentation on System Services is spartan as it is, but its documentation on standalone services is non-existant.
What I have thus far is an Xcode project built from the bundle package, with the two sources HashifyService.h and HashifyService.m. Here is the test code I have:
- (void) doServiceWork:(NSPasteboard *)pboard
userData:(NSString *)userData
error:(NSString **)error {
NSLog(#"Actually in the service now");
NSString *pboardString;
NSArray *types;
NSLog(#"do test magic service! (pboard: %#, types: %#)", pboard, [pboard types]);
NSString* outputString = #"It Worked";
types = [NSArray arrayWithObject:NSStringPboardType];
[pboard declareTypes:types owner:nil];
[pboard setString:outputString forType:NSStringPboardType];
[outputString release];
return;
}
and this is the NSServices entry in my Info.plist:
<dict>
<key>NSMenuItem</key>
<dict>
<key>Menu item title</key>
<string>HashifyTest</string>
</dict>
<key>NSMessage</key>
<string>doServiceWork</string>
<key>NSPortName</key>
<string>HashifyService</string>
<key>NSReturnTypes</key>
<array>
<string>NSStringPboardType</string>
</array>
<key>NSSendTypes</key>
<array>
<string>NSStringPboardType</string>
</array>
</dict>
I then build the service bundle and place it in ~/Library/Services/ where it is appropriately detected and I am given the option to use the service. Upon activating the service, however, an error occurs and is logged to Console:
..../Hashify.service/Contents/MacOS/Hashify: cannot execute binary file
What am I doing wrong?

Answer 1

You need a main() function. That should register the service using NSRegisterServicesProvider() and enter the run loop. That is in the documentation.