I see you just want to see what command line arguments it was launched with. I know a js-ctypes solution. That will require you to code for the different platforms. Here's a start, it gets you the arguments on windows and mac. I didnt do the linux part yet:
Cu.import('resource://gre/modules/osfile.jsm');
Cu.import('resource://gre/modules/ctypes.jsm');
var lib 
var osname = OS.Constants.Sys.Name.toLowerCase();
if (osname.indexOf('win') === 0) {
    // windows
    lib = ctypes.open('kernel32');
    var GetCommandLineW = lib.declare('GetCommandLineW', ctypes.winapi_abi,  ctypes.jschar.ptr);
    var rez = GetCommandLineW();
    console.log('rez:', rez.readString());
} else if (osname == 'darwin') {
    // mac
    lib = ctypes.open(ctypes.libraryName('objc'));
    // BASIC TYPES
    var BOOL = ctypes.signed_char;
    var NSUINTEGER = ctypes.unsigned_long;
    // COMMON FUNCTIONS
    var objc_getClass = lib.declare('objc_getClass', ctypes.default_abi, ctypes.voidptr_t, ctypes.char.ptr);
    var objc_msgSend = lib.declare('objc_msgSend', ctypes.default_abi, ctypes.voidptr_t, ctypes.voidptr_t, ctypes.voidptr_t, '...');
    var sel_registerName = lib.declare('sel_registerName', ctypes.default_abi, ctypes.voidptr_t, ctypes.char.ptr);
    // current_application = [NSRunningApplication currentApplciation];
    var NSProcessInfo = objc_getClass('NSProcessInfo');
    var processInfo = sel_registerName('processInfo');
    var process_info = objc_msgSend(NSProcessInfo, processInfo);
    // bundle_identifier = [current_application bundleIdentifier]
    var arguments = sel_registerName('arguments');
    var args = objc_msgSend(process_info, arguments);
    var count = sel_registerName('count');
    var _count = objc_msgSend(args, count);
    console.info('_count:', _count, _count.toString(), uneval(_count), parseInt(_count));
    // make it into a js number
    _count = parseInt(ctypes.cast(_count, NSUINTEGER).value); 
    console.log('_count:', _count);
    var objectAtIndex = sel_registerName('objectAtIndex:'); // used in for loop
    var UTF8String = sel_registerName('UTF8String'); // used in for loop
    for (var i=0; i<_count; i++) {
        var arg = objc_msgSend(args, objectAtIndex, NSUINTEGER(i)); // must wrap `i` in NSUINTEGER as its variadic, you have to specify the type. this is specific to js-ctypes         
        var argString = ctypes.cast(objc_msgSend(arg, UTF8String), ctypes.char.ptr);
        console.log('arg "' + i + '":', argString.readStringReplaceMalformed(), 'arg:', arg, arg.toString(), uneval(arg));
    }
} else {
    // *nix
    // todo
    // per - http://stackoverflow.com/a/821889/1828637
    var libcPaths = ['libc.so', 'libc.so.7', 'libc.so.61.0', 'libc.so.6', 'libc.so.0.1', 'libc.dylib'];
    for (var i=0; i<libcPaths.length; i++) {
        try {
            lib = ctypes.open(libcPaths[i]);
            break;
        } catch(ignore) {}
    }
    if (!lib) {
        throw new Error('failed to find libc on this system');
    }
    var popen = lib.declare('popen', ctypes.default_abi, ctypes.voidptr_t, ctypes.char.ptr, ctypes.char.ptr);
    var fread = lib.declare('fread', ctypes.default_abi, ctypes.size_t, ctypes.voidptr_t, ctypes.size_t, ctypes.size_t, ctypes.voidptr_t);
    var feof = lib.declare('feof', ctypes.default_abi, ctypes.int, ctypes.voidptr_t);
    var pclose = lib.declare('pclose', ctypes.default_abi, ctypes.int, ctypes.voidptr_t);
    var getpid = lib.declare('getpid', ctypes.default_abi, ctypes.int32_t);
    // ps -fp 2540
    var pid = getpid();
    var file = popen('ps -ww -fp' + pid, 'r');
    var buf = ctypes.char.array(100)();
    var jsbuf = [];
    var reachedEof = false;
    while (!reachedEof) {
        var cnt = fread(buf, 1, buf.length * buf.constructor.elementType.size, file);
        cnt = parseInt(cnt);
        if (cnt > 0) {
            jsbuf.push(buf.readString().substring(0, cnt));
        }
        reachedEof = feof(file);
    }
    var closeit = pclose(file);
    console.log('closeit:', closeit);
    console.log('jsbuf:', jsbuf.join(''));
}
lib.close();