gistfile1.m

-(NSMutableData*) createHTTPPostBodyWithParameters:(NSDictionary*)params boundary:(NSString*)boundary
{
  NSMutableData *paramsData = [NSMutableData new];
  NSString      *enter      = @"\r\n";

  for(id key in params) {
    [paramsData appendData:[[NSString stringWithFormat:@"--%@%@", boundary, enter] dataUsingEncoding:NSUTF8StringEncoding]];
    [paramsData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"", key] dataUsingEncoding:NSUTF8StringEncoding]];

    // File
    if(key == @"file") {
      id filePath = [params valueForKey:key];
      id fileName = [filePath lastPathComponent];
      id fileData = [NSData dataWithContentsOfFile:filePath];

      [paramsData appendData:
        [[NSString stringWithFormat:@"; filename=\"%@\"%@", fileName, enter] dataUsingEncoding:NSUTF8StringEncoding]];
      [paramsData appendData:
        [[NSString stringWithFormat:@"Content-Type: application/octet-stream%@%@", enter, enter] dataUsingEncoding:NSUTF8StringEncoding]];
      [paramsData appendData:fileData];
      NSLog(@"%d", [fileData length]);
    // not File
    } else {
      [paramsData appendData:[[NSString stringWithFormat:@"%@%@", enter, enter] dataUsingEncoding:NSUTF8StringEncoding]];
      [paramsData appendData:[[params valueForKey:key] dataUsingEncoding:NSUTF8StringEncoding]];
    }
    [paramsData appendData:[[NSString stringWithFormat:@"%@", enter] dataUsingEncoding:NSUTF8StringEncoding]];
  }

  // source
  [paramsData appendData:[[NSString stringWithFormat:@"--%@%@", boundary, enter] dataUsingEncoding:NSUTF8StringEncoding]];
  [paramsData appendData:[@"Content-Disposition: form-data; name=\"source\"" dataUsingEncoding:NSUTF8StringEncoding]];
  [paramsData appendData:[[NSString stringWithFormat:@"%@%@", enter, enter] dataUsingEncoding:NSUTF8StringEncoding]];
  [paramsData appendData:[[NSString stringWithFormat:@"%@%@", [USER_AGENT valueForKey:@"name"], enter] dataUsingEncoding:NSUTF8StringEncoding]];

  // term
  [paramsData appendData:[[NSString stringWithFormat:@"--%@--", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

  return paramsData;
}