Add text to existing txt file [duplicate] - iphone

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write data line by line on iphone
(4 answers)
Closed 9 years ago.
How can I add text from UITextField, separated by comma to existing txt file?
I use this code:
NSString *imageName = [NSString stringWithFormat:#"Documents/text.txt"];
NSString *textPath = [NSHomeDirectory() stringByAppendingPathComponent:imageName];
NSString *word = [NSString stringWithFormat:#"%# ,", _wordInput.text];
[word writeToFile:textPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
As you can see, I use this code to add a text from _wordInput which is my UITextField, and add comma. After that I use writeToFile option to write text to my text.txt file.
I tested, and works great, but, every time it will overwrite existing text..
Help please to NOT OVERWRITE TEXT, BUT separate by comma.
Let's say my UITextField has text "earth" at this moment, I will press a button, and the above code will run.. Now my text.txt file will contain "earth ," if I will enter another text on UITextField and run above code, the existing text will be overwrite, but I need it to be added after "earth ,"
Thanks.

Answer 1

It is better to use something like below function:
-(void)saveText:(NSString*)data
{
NSString *imageName = [NSString stringWithFormat:#"Documents/text.txt"];
NSString *textPath = [NSHomeDirectory() stringByAppendingPathComponent:imageName];
NSString *word = [NSString stringWithFormat:#"%# ,", _wordInput.text];
NSFileHandle *fileHandler= [NSFileHandle fileHandleForWritingAtPath:textPath];
[fileHandler seekToEndOfFile];
[fileHandler writeData:[word dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandler closeFile];
}

Answer 2

You need to include the original text when you write it back. Something like this:
NSString *imageName = [NSString stringWithFormat:#"Documents/text.txt"];
NSString *textPath = [NSHomeDirectory() stringByAppendingPathComponent:imageName];
NSString *existingFileContents = [NSString stringWithContentsOfFile:textPath encoding:NSUTF8StringEncoding error:nil];
NSString *newFileContents = [NSString stringWithFormat:#"%#, %#", existingFileContents, _wordInput.text];
[newFileContents writeToFile:textPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
I would assume that using system api calls like write() or fwrite() would be more efficient, but I've never measured it. If your text file is large, you might want to look into it.