如何将缓冲区打印到通过寻呼机通过管道输出的stdout？

Question

I have a large buffer (buffer []byte) that I would like to print to stdout but pipe through a pager like less or more. Kind of like the man command. I don't want to write the buffer to tmp file first or make the user manually pipe the output to a pager on the command line.

I can find examples of how to pipe the output of one command to another, but nothing starting with an internal buffer.

Any ideas? Thanks.

Answer 1

In order to pipe to a pager, you can do something like this:

package main

import (
        "fmt"
        "io"
        "os"
        "os/exec"
)

func main() {
        // declare your pager
        cmd := exec.Command("less")
        // create a pipe (blocking)
        r, stdin := io.Pipe()
        // Set your i/o's
        cmd.Stdin = r
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr

        // Create a blocking chan, Run the pager and unblock once it is finished
        c := make(chan struct{})
        go func() {
                defer close(c)
                cmd.Run()
        }()

        // Pass anything to your pipe
        fmt.Fprintf(stdin, "hello world
")

        // Close stdin (result in pager to exit)
        stdin.Close()

        // Wait for the pager to be finished
        <-c
}