Deleting contents of text file

Question

I'm reading and writing to a text file. There is an instance where I want to delete the contents of the file (but not the file) as a kind of reset. How can I do this?

if ((dirs) != nil) {
    var dir = dirs![0]; //documents directory

    let path = dir.stringByAppendingPathComponent("UserInfo.txt");
    println(path)
    let text = "Rondom Text"

    //writing
    text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil)

    //reading
    let text2 = String(contentsOfFile: path, encoding: NSUTF8StringEncoding, error: nil)

    println(text2)

Nothing wrong with the above code. I would just like to know how to delete the contents of the file... i.e. here I'm writing to the file and then the user presses reset, so the file becomes empty. — TurtleFan, Aug 23 '15 at 05:40
`"".writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil)` The file will have cleared. — Bannings, Aug 23 '15 at 05:43

score 11 · Accepted Answer · answered Aug 23 '15 at 06:03

11

Simply write an empty string to the file like this:

let text = ""
text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil)

answered Aug 23 '15 at 06:03

Bannings

10,376
7
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score 7 · Answer 2 · answered Aug 23 '15 at 05:49

If you set up an NSFileHandle, you can use -truncateFileAtOffset:, passing 0 for the offset.

Or, as pointed out in comments, you can simply write an empty string or data to the file.

Or you can use some kind of data structure / database that does not require you to manually truncate files :)

score 4 · Answer 3 · edited Feb 06 '18 at 07:49

4

Swift 3.x

let text = ""
do {
     try text.write(toFile: fileBundlePath, atomically: false, encoding: .utf8)
} catch {
     print(error)
}

Swift 4.x

let text = ""
do {
     try text.write(to: filePath, atomically: false, encoding: .utf8)
   } catch {
     print(error)
   }

edited Feb 06 '18 at 07:49

IOS Singh

617
6
15

answered Jul 07 '17 at 07:15

Alessandro Ornano

34,887
11
106
133

Deleting contents of text file

3 Answers3