How to know what Mac OS the app is running on?

Question

I\'ve seen in some projects something like:

#if .....
    code...
#endif

but i can\'t find it now...
Let\'s say, for example, if the ap

Answer 1

Here is code for how I do it. I love it this way, mainly because I don't have to A) Rely on an NSTask or B) Rely on any File I/O that many processes have access to.

static NSString* const kVarSysInfoVersionFormat  = @"%@.%@.%@ (%@)";
static NSString* const kVarSysInfoKeyOSVersion = @"kern.osrelease";
static NSString* const kVarSysInfoKeyOSBuild   = @"kern.osversion";

- (NSString *) _strControlEntry:(NSString *)ctlKey {

    size_t size = 0;
    if ( sysctlbyname([ctlKey UTF8String], NULL, &size, NULL, 0) == -1 ) return nil;

    char *machine = calloc( 1, size );

    sysctlbyname([ctlKey UTF8String], machine, &size, NULL, 0);
    NSString *ctlValue = [NSString stringWithCString:machine encoding:[NSString defaultCStringEncoding]];

    free(machine); return ctlValue;
}

- (NSString *) getOSVersionInfo {

    NSString *darwinVer = [self _strControlEntry:kVarSysInfoKeyOSVersion];
    NSString *buildNo = [self _strControlEntry:kVarSysInfoKeyOSBuild];
    if ( !darwinVer || !buildNo ) return nil;

    NSString *majorVer = @"10", *minorVer = @"x", *bugFix = @"x";
    NSArray *darwinChunks = [darwinVer componentsSeparatedByCharactersInSet:[NSCharacterSet punctuationCharacterSet]];

    if ( [darwinChunks count] > 0 ) {

        NSInteger firstChunk = [(NSString *)[darwinChunks objectAtIndex:0] integerValue];
        minorVer = [NSString stringWithFormat:@"%ld", (firstChunk - 4)];
        bugFix = [darwinChunks objectAtIndex:1];

    } return [NSString stringWithFormat:kVarSysInfoVersionFormat, majorVer, minorVer, bugFix, buildNo];
}

Enjoy!