You may have noticed that an instance of NSError
includes a property called domain
. This is a string, three of which are defined: NSPOSIXErrorDomain
, NSOSStatusErrorDomain
, and NSMachErrorDomain
. Each domain has error codes unique to it, or at least have special meaning in their contexts.
For NSPOSIXErrorDomain
, look in sys/errno.h
.
Likewise, for NSOSStatusErrorDomain
, look in CarbonCore/MacErrors.h
.
For NSMachErrorDomain
, look in mach/error.h
.
Frameworks can define their own domains, and an example of this is NSCocoaErrorDomain
, for which you should look in Foundation/FoundationErrors.h
.
Keep in mind that you can define your own error domains and codes you in your own projects.
Good luck to you in your endeavors.