1 files changed, 155 insertions, 0 deletions
diff --git a/src/os/exec/example_test.go b/src/os/exec/example_test.go
new file mode 100644
index 0000000..a66890b
--- /dev/null
+++ b/src/os/exec/example_test.go
@@ -0,0 +1,155 @@
+// 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"
+	"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, _ := io.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.
+	}
+}