I noticed a strange problem on iOS. Consider this code:
#import <Foundation/Foundation.h>
#include <fstream>
#include <string>
#include <iostream>
#include <vector>
int main(int argc, char * argv[]) {
		NSArray* args = NSProcessInfo.processInfo.arguments;
		for(int i = 0; i < args.count; ++i)
		{
				std::cout<<"Arg "<<i<<" "<<[args[i] UTF8String] <<std::endl;		
		}
		NSArray<NSURL *> *urls =
				[[NSFileManager defaultManager]
						URLsForDirectory:NSDocumentDirectory
									 inDomains:NSUserDomainMask];	
		NSString *filename = [[urls[0] path]
															 stringByAppendingString: @"/file.txt"];	
	
		std::ofstream f1([filename UTF8String], std::ios::trunc);		
		if(args.count > 3)
		{
				std::cout<<"More than 3 args"<<std::endl;
				f1<<"More than 3 args"<<std::endl;
		}
		else
		{
				std::cout<<"Less or equal to 3 args"<<std::endl;
				f1<<"Less or equal to 3 args"<<std::endl;
		}
}
It checks the number of command line arguments. If it is larger than 3 prints a message to console and to a file. Else outputs a different message. I set the input arguments by editing Xcode scheme. Here is the console output when I pass more than 3 input args:
Arg 0 /var/containers/Bundle/Application/6354AF7F-6817-423D-88FD-976813627552/CLIArgTest.app/CLIArgTest
Arg 1 hrhtrnd
Arg 2 ebyrebyes
Arg 3 fvtrvter
Arg 4 jvojeojgreo
More than 3 args
However, when I extract the output file from the on device Document folder of the iOS app, I get:
Less or equal to 3 args
I don’t get this problem if I run the exact same code on MacOS.
I tried building both debug and release and it makes no difference.
I tried writing to file using ObjC and C++ API, no difference.
I tried using argc/argv directly instead of NSProcessInfo.processInfo.arguments, no difference.
I couldn’t find any references to this problem online. Although admittedly very few people do this type of command line based dev on iOS. The reason I need to do this is because I am trying to build a unit testing app around a library I wrote and I would like to control some test parameters using command line arguments.
dwayneduane
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