Question

I have managed to write to a text file but I want to be able to add more data to the text file without overwriting the current contents of the text file. So in other words, I want to write to the end of the file each time so it doesn’t erase current content. The following code is what I have done so far but it overwrites every time and writes to the beginning, I am not sure how to get it write to the end. Based on this code, the current content in the textfile looks like:

June
July
August
September

I want to be able to add the following for example

 June
 July
 August
 September
 October

Does anyone know how to this? Thanks!

-(void) writeToTextFile{
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *fileName = [NSString stringWithFormat:@"%@/textfile.txt", 
                      documentsDirectory];
//create content - four lines of text
NSString *content = @"June\nJuly\nAugust\nSeptember";
//save content to the documents directory
[content writeToFile:fileName 
          atomically:NO 
            encoding:NSStringEncodingConversionAllowLossy 
               error:nil];

 }

Answer 1

Use this method to write at End of file:

-(void) writeToTextFileWithString:(NSString *) content name:(NSString *) file {

  //TODO: Disable logs at release time

  content = [NSString stringWithFormat:@"%@ |||   %@\n",content,[[NSDate date] description]];

  //get the documents directory:
  NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
  NSString *fileName = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.txt",file]];

  NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:fileName];
  if (fileHandle){

    [fileHandle seekToEndOfFile];
    [fileHandle writeData:[content dataUsingEncoding:NSUTF8StringEncoding]];
    [fileHandle closeFile];
  }
  else{

    [content writeToFile:fileName
              atomically:NO
                encoding:NSStringEncodingConversionAllowLossy
                   error:nil];
  }
}