NSString's initWithContentsOfFile is failing to load any zip File.

Question

Server requirement is to post zip file along with some string data. Here I am facing 2 problem.

1. in below code my "NSString *filecontent" value is nil. where (const char *)file is path of zip file
2. how can I post data on server.

- (void)postDataOnServerFilePath:(const char *)file withEmail:(const char *)email withDescription :(const char *)description withLanguage:(const char *)language {
    NSError*error = nil;
    NSString *content = [NSString stringWithUTF8String:file];
    NSString *filecontent = [[NSString alloc] initWithContentsOfFile:content encoding:NSUTF8StringEncoding error:&error];
     NSString *post = [NSString stringWithFormat:@"EMail=%s&Description=%s&Language=%s&Filename=%s&File=%@",email,description,language,file,filecontent];
    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
    NSString *postLength = [NSString stringWithFormat:@"%lu",(unsigned long)[postData length]];
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:@"https://swlic.info/SharedDictionaries/userdictionary.ashx"]];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];
    NSHTTPURLResponse* response =[[NSHTTPURLResponse alloc] init];
    error = nil;
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    if (error){}
    NSString *responseString = [[NSString alloc] initWithBytes:[responseData bytes]
                                                        length:[responseData length]
                                                      encoding:NSUTF8StringEncoding];
    NSLog(@"%@", responseString);
}

Answer 1

You can send binary data as text, but you must encode the raw data first (e.g. as a base64-encoded string).

Either way, your main problem is that none of your data is URL-encoded. A URL cannot contain arbitrary binary data, and neither can a URL-encoded POST body. Each of those values that you're inserting into the POST body string (email, etc.) needs to be URL-encoded before you add it to that string. Otherwise someone cam put ampersands into an email address and break things badly. (And a ZIP file will contain those disallowed characters.)

For details, see:

https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/URLLoadingSystem/WorkingwithURLEncoding/WorkingwithURLEncoding.html