Objective-C++ program to decode an IOReturn/kern_return_t value

ioreturndecode.mm

//  Decodes an IOReturn/kern_return_t value.
//  See https://developer.apple.com/library/content/qa/qa1075/_index.html for details

#include <iostream>
#include <iomanip>

#include <mach/error.h>

using std::cout;
using std::cerr;
using std::endl;
using std::hex;
using std::dec;
using std::stol;
using std::showbase;

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        if (argc > 1) {
            for (int i = 1; i < argc; ++i) {
                auto err = stol(argv[1], 0, 0);
                
                cout << showbase
                     << hex << err
                     << dec << "(" << err <<")"
                     << hex
                     << ": system="    << err_get_system(err)
                     << "; subsystem=" << err_get_sub(err)
                     << "; code="      << err_get_code(err)
                     << endl;
            }
        }
        else {
            cerr << "usage: " << argv[0] << "CODE...";
        }
    }
    return 0;
}