Writing to log file seems to overwrite previous save - swift

Question

As an exercise, I'm trying to write a logging class that logs strings to a text file. I've got my application to write and read from the file. However, if I try to log multiple times it seems to only pick up the most recent log.
Attempt
writing
private let file = "logfile.txt"
func write(text: String) {
let path = getDocumentsDirectory()
do {
try text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding)
}
catch let error {
print("error: \n \(error)")
}
}
reading
func read() {
let path = getDocumentsDirectory()
do {
let text2 = try String(contentsOfFile: path, encoding: NSUTF8StringEncoding)
print("From Log: \n \(text2)")
}
catch let error {
print("error: \n \(error)")
}
}
func getDocumentsDirectory() -> String {
guard let dir : NSString = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first else {
return ""
}
let documentsDirectory : String = dir.stringByAppendingPathComponent(file)
return documentsDirectory
}
Result
When I try to read my file I only get the last line saved.
Question
If my goal is to endlessly append new logs to a file, and to read the log file in bulk. What changes to my code do I need to make?
more details:
I'm writing to the file on application load:
Logger.shared.write("instance one writes")
Logger.shared.write("instance one writes again")
Logger.shared.write("instance one writes yet again")
and then attempting to read:
Logger.shared.read()
output:
From Log:
instance one writes yet again

Answer 1

The writeToFile(_:atomically:encoding:) method provided by Foundation replaces the contents of the given file. There are several ways of appending to files:
Plain ol’ fopen (with mode "a") and fwrite.
NSOutputStream, such as NSOutputStream(toFileAtPath: mypath, append: true), using stream.write(bytes, len) to write data.
Perhaps the easiest, NSFileHandle, such as NSFileHandle(forWritingAtPath: mypath), using seekToEndOfFile() and writeData().