tail

Tail a file programmatically just like you run shell command tail -f /somefile.

Features

• support tail a non-exist file until that file exists
• tail works even if file get removed or truncated
• tail from specified offset

Basic usage

// closeFunc is used to stop tailing
lineCh, closeFunc, errCh := tail.TailF("/path/to/file", true)
go func() {
    for {
        select {
        case <-errCh:
            return
        case line := <-lineCh:
            fmt.Println(line)
        }
    }
}()

Advance usage

by default, tail poll file delete/truncate-event every 10 seconds, you can config poll interval to satisfy your own needs.

lineCh, closeFunc, errCh := tail.TailWithConfig("/path/to/file", true, &tail.Config{PollInterval: 500 * time.Millisecond})
go func() {
    for {
        select {
        case <-errCh:
            return
        case line := <-lineCh:
            fmt.Println(line)
        }
    }
}()

More configs

config tail offset

// tail.SeekFromStart/tail.SeekFromEnd/tail.SeekOffsetAuto
lineCh, closeFunc, errCh := tail.TailWithConfig("/path/to/file", true, &tail.Config{
		PollInterval: 500 * time.Millisecond, 
		Offset: tail.SeekFromStart,
})

Limitations

Not tested on windows.