phantom_bug.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"os/exec"
	"strings"
	"time"
)

const script = `
(function(){
	var fs = require('fs'),
		system = require('system');
	console.log('hi from phantomjs');
	console.log(JSON.stringify(system.os));
	var s = fs.open('/dev/fd/3', 'r'),
		line;
	while(line = s.readLine()) { // this blocks forever until fd3 is closed.
		console.log('phantomjs: ', line);
	}
	s.close();
	phantom.exit();
})();
`

func main() {
	cp := "phantomjs"
	if len(os.Args) > 1 {
		if os.Args[1] == "/dev/stdin" {
			mainChild()
			return
		}
		cp = os.Args[0]
	}
	cmd := exec.Command(cp, "/dev/stdin")
	cmd.Stdin = strings.NewReader(script)

	rp, wp, err := os.Pipe()
	if err != nil {
		return
	}
	defer rp.Close()

	cmd.ExtraFiles = []*os.File{rp}
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err = cmd.Start(); err != nil {
		return
	}
	rp.Close()
	wp.WriteString("test 1\n")
	wp.WriteString("test 2\n")
	wp.WriteString("test 3\n")
	time.AfterFunc(1*time.Second, func() {
		fmt.Println("---timing out---")
		wp.Close()
	})
	cmd.Wait()
}

func mainChild() {
	f := os.NewFile(3, "fd3")
	buf := bufio.NewReader(f)
	fmt.Println("hi from go")
	for {
		line, err := buf.ReadString('\n')
		if err != nil {
			break
		}
		fmt.Println("go:", strings.TrimSpace(line))
	}
}