Is there a way to pass command line options to my iOS app from Xcode?

Question

I'm hoping to find a method to pass certain information in to my app when I launch it during testing, so that I can perform special debug tasks. Xcode has a section "Arguments Passed on Launch", and I assumed they would show up in my UIApplicationDelegate's application:didFinishLaunchingWithOptions: but the dictionary that's passed in is always nil.

Am I going about this the wrong way?

Answer 1

You can access them using NSProcessInfo object like this,

NSArray * arguments = [[NSProcessInfo processInfo] arguments];

Answer 2

Another easier way is to use the NSUserDefaults.

http://perspx.com/archives/parsing-command-line-arguments-nsuserdefaults/

From the article:

Command line arguments that can be parsed and used by the NSArgumentDomain must take the format:

 -name value

The argument is stored as a default with key of name and value of value . At this point accessing values passed in on the command line is the same process for accessing any other defaults.

For example running an application as such:

 MyApplication -aString "Hello, World" -anInteger 10

allows the command line arguments to be retrieved as such:

 NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults]; NSString *aString = [standardDefaults stringForKey:@"aString"]; NSInteger anInteger = [standardDefaults integerForKey:@"anInteger"];

Answer 3

For those who stumbled to this question like me:) I wanted to have a logLevel for my static lib. The way I did is,

static NSUInteger logLevel = 1;
/** This argument should be passed from XCode's build scheme configuration option, Arguments passed on launch */
static const NSString *kIdcLogLevelArgument = @"-com.mycompany.IDCLogLevel";

@implementation IDCLogger

+ (instancetype)sharedInstance {
    static id sharedInstance = nil;

    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedInstance = [[self alloc] init];
    });

    return sharedInstance;
}

+(void)initialize
{
    logLevel = 1;
    NSArray *arguments = [[NSProcessInfo processInfo] arguments];
    NSUInteger value = 0;

    if ([arguments containsObject:kIdcLogLevelArgument]) {
        NSUInteger index = [arguments indexOfObject:kIdcLogLevelArgument];
        if (arguments.count > index) {
            NSString *valueStr = [arguments objectAtIndex:index + 1];
            NSCharacterSet* notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
            if ([valueStr rangeOfCharacterFromSet:notDigits].location == NSNotFound)
            {
                value = [valueStr integerValue];
                logLevel = value;
            }
        }
    }
    NSLog(@"%@:logLevel = %lu", [self class], (unsigned long)logLevel);
}

+ (void)setLogLevel:(NSUInteger)l
{
    logLevel = l;
    NSLog(@"[%@]: Log level set to: %lu", [self class], (unsigned long)l);
}

Answer 4

In addition to scalars, command line arguments can be an NSData, NSArray, or NSDictionary references. Apple's documentation on "Old-Style ASCII Property Lists" tells how to do it. https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/PropertyLists/OldStylePlists/OldStylePLists.html#//apple_ref/doc/uid/20001012-BBCBDBJE

For example, this syntax should decode into an NSDictionary:

MyApplication -aLocation "{ latitude = 37.40089; longitude = -122.109428; }"