package main
import (
"bytes"
"fmt"
"log"
"os"
"os/exec"
)
func main() {
argNum := len(os.Args)
if argNum < 2 {
log.Printf("Usage:%s command\n", os.Args[0])
os.Exit(1)
}
arg := []string{}
if argNum > 2 {
arg = os.Args[2:]
}
mainOutput(UsePipe(os.Args[1], arg...))
}
func mainOutput(out []byte, err error) {
if err != nil {
log.Fatal(err)
}
fmt.Printf("The output of command %q is\n%s\n", os.Args[1], out)
}
// 直接给 Cmd.Stdout 赋值
func FillStd(name string, arg ...string) ([]byte, error) {
cmd := exec.Command(name, arg...)
var out = new(bytes.Buffer)
cmd.Stdout = out
cmd.Stderr = out
err := cmd.Run()
if err != nil {
return nil, err
}
return out.Bytes(), nil
}
func UseOutput(name string, arg ...string) ([]byte, error) {
return exec.Command(name, arg...).Output()
}
// 使用 Pipe
func UsePipe(name string, arg ...string) ([]byte, error) {
cmd := exec.Command(name, arg...)
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil, err
}
if err = cmd.Start(); err != nil {
return nil, err
}
var out = make([]byte, 0, 1024)
for {
tmp := make([]byte, 128)
n, err := stdout.Read(tmp)
out = append(out, tmp[:n]...)
if err != nil {
break
}
}
if err = cmd.Wait(); err != nil {
return nil, err
}
return out, nil
}