157 lines
3.2 KiB
Go
157 lines
3.2 KiB
Go
// Copyright 2012 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package exec_test
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"log"
|
|
"os"
|
|
"os/exec"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
func ExampleLookPath() {
|
|
path, err := exec.LookPath("fortune")
|
|
if err != nil {
|
|
log.Fatal("installing fortune is in your future")
|
|
}
|
|
fmt.Printf("fortune is available at %s\n", path)
|
|
}
|
|
|
|
func ExampleCommand() {
|
|
cmd := exec.Command("tr", "a-z", "A-Z")
|
|
cmd.Stdin = strings.NewReader("some input")
|
|
var out bytes.Buffer
|
|
cmd.Stdout = &out
|
|
err := cmd.Run()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
fmt.Printf("in all caps: %q\n", out.String())
|
|
}
|
|
|
|
func ExampleCommand_environment() {
|
|
cmd := exec.Command("prog")
|
|
cmd.Env = append(os.Environ(),
|
|
"FOO=duplicate_value", // ignored
|
|
"FOO=actual_value", // this value is used
|
|
)
|
|
if err := cmd.Run(); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|
|
|
|
func ExampleCmd_Output() {
|
|
out, err := exec.Command("date").Output()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
fmt.Printf("The date is %s\n", out)
|
|
}
|
|
|
|
func ExampleCmd_Run() {
|
|
cmd := exec.Command("sleep", "1")
|
|
log.Printf("Running command and waiting for it to finish...")
|
|
err := cmd.Run()
|
|
log.Printf("Command finished with error: %v", err)
|
|
}
|
|
|
|
func ExampleCmd_Start() {
|
|
cmd := exec.Command("sleep", "5")
|
|
err := cmd.Start()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
log.Printf("Waiting for command to finish...")
|
|
err = cmd.Wait()
|
|
log.Printf("Command finished with error: %v", err)
|
|
}
|
|
|
|
func ExampleCmd_StdoutPipe() {
|
|
cmd := exec.Command("echo", "-n", `{"Name": "Bob", "Age": 32}`)
|
|
stdout, err := cmd.StdoutPipe()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
if err := cmd.Start(); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
var person struct {
|
|
Name string
|
|
Age int
|
|
}
|
|
if err := json.NewDecoder(stdout).Decode(&person); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
if err := cmd.Wait(); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
fmt.Printf("%s is %d years old\n", person.Name, person.Age)
|
|
}
|
|
|
|
func ExampleCmd_StdinPipe() {
|
|
cmd := exec.Command("cat")
|
|
stdin, err := cmd.StdinPipe()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
go func() {
|
|
defer stdin.Close()
|
|
io.WriteString(stdin, "values written to stdin are passed to cmd's standard input")
|
|
}()
|
|
|
|
out, err := cmd.CombinedOutput()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
fmt.Printf("%s\n", out)
|
|
}
|
|
|
|
func ExampleCmd_StderrPipe() {
|
|
cmd := exec.Command("sh", "-c", "echo stdout; echo 1>&2 stderr")
|
|
stderr, err := cmd.StderrPipe()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
if err := cmd.Start(); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
slurp, _ := ioutil.ReadAll(stderr)
|
|
fmt.Printf("%s\n", slurp)
|
|
|
|
if err := cmd.Wait(); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|
|
|
|
func ExampleCmd_CombinedOutput() {
|
|
cmd := exec.Command("sh", "-c", "echo stdout; echo 1>&2 stderr")
|
|
stdoutStderr, err := cmd.CombinedOutput()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
fmt.Printf("%s\n", stdoutStderr)
|
|
}
|
|
|
|
func ExampleCommandContext() {
|
|
ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
|
|
defer cancel()
|
|
|
|
if err := exec.CommandContext(ctx, "sleep", "5").Run(); err != nil {
|
|
// This will fail after 100 milliseconds. The 5 second sleep
|
|
// will be interrupted.
|
|
}
|
|
}
|