Method First

script.go:580–597

First produces only the first n lines of the pipe's contents, or all the lines if there are less than n. If n is zero or negative, there is no output at all. When n lines have been produced, First stops reading its input and sends EOF to its output.

(n int)

// at all. When n lines have been produced, First stops reading its input and
// sends EOF to its output.
func (p *Pipe) First(n int) *Pipe {
	if p.Error() != nil {
		return p
	}
	if n <= 0 {
		return NewPipe()
	}
	return p.Filter(func(r io.Reader, w io.Writer) error {
		scanner := newScanner(r)
		for i := 0; i < n && scanner.Scan(); i++ {
			_, err := fmt.Fprintln(w, scanner.Text())
			if err != nil {
				return err
			}
		}
		return scanner.Err()
	})
}

// Freq produces only the unique lines from the pipe's contents, each prefixed
// with a frequency count, in descending numerical order (most frequent lines