1 // Copyright 2012 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package exec_test 6 7 import ( 8 "bytes" 9 "encoding/json" 10 "fmt" 11 "log" 12 "os/exec" 13 "strings" 14 ) 15 16 func ExampleLookPath() { 17 path, err := exec.LookPath("fortune") 18 if err != nil { 19 log.Fatal("installing fortune is in your future") 20 } 21 fmt.Printf("fortune is available at %s\n", path) 22 } 23 24 func ExampleCommand() { 25 cmd := exec.Command("tr", "a-z", "A-Z") 26 cmd.Stdin = strings.NewReader("some input") 27 var out bytes.Buffer 28 cmd.Stdout = &out 29 err := cmd.Run() 30 if err != nil { 31 log.Fatal(err) 32 } 33 fmt.Printf("in all caps: %q\n", out.String()) 34 } 35 36 func ExampleCmd_Output() { 37 out, err := exec.Command("date").Output() 38 if err != nil { 39 log.Fatal(err) 40 } 41 fmt.Printf("The date is %s\n", out) 42 } 43 44 func ExampleCmd_Start() { 45 cmd := exec.Command("sleep", "5") 46 err := cmd.Start() 47 if err != nil { 48 log.Fatal(err) 49 } 50 log.Printf("Waiting for command to finish...") 51 err = cmd.Wait() 52 log.Printf("Command finished with error: %v", err) 53 } 54 55 func ExampleCmd_StdoutPipe() { 56 cmd := exec.Command("echo", "-n", `{"Name": "Bob", "Age": 32}`) 57 stdout, err := cmd.StdoutPipe() 58 if err != nil { 59 log.Fatal(err) 60 } 61 if err := cmd.Start(); err != nil { 62 log.Fatal(err) 63 } 64 var person struct { 65 Name string 66 Age int 67 } 68 if err := json.NewDecoder(stdout).Decode(&person); err != nil { 69 log.Fatal(err) 70 } 71 if err := cmd.Wait(); err != nil { 72 log.Fatal(err) 73 } 74 fmt.Printf("%s is %d years old\n", person.Name, person.Age) 75 } 76
