Go execute shell command

func main() {
    cmd := exec.Command("ls", "-lah")
    out, err := cmd.CombinedOutput()
    if err != nil {
        log.Fatalf("cmd.Run() failed with %s\n", err)
    }
    fmt.Printf("combined out:\n%s\n", string(out))

    
    // For example, I now have a scheduled task to perform , Encapsulate a method for automatic execution 
    cmdStr := "cd /go/leyangjun/test/ && ./main crontab --run=single --job=myCrontabName"
    runCmd := exec.Command("/bin/bash", "-c", cmdStr)
	runCmdOut, err := runCmd.CombinedOutput()
	if err != nil {
		fmt.Println(" Command execution failed ")
	}else{

        fmt.Println(" Command executed successfully ")
    }

}



// Check if the command exists 
func checkExists() {
    path, err := exec.LookPath("pwd")
    if err != nil {
        fmt.Printf("pwd non-existent \n")
    } else {
        fmt.Printf("'pwd' executable is in '%s'\n", path)
    }
}


// The two commands are executed in sequence 
func successivelyExists() {
    c1 := exec.Command("ls")
    c2 := exec.Command("wc", "-l")
    c2.Stdin, _ = c1.StdoutPipe()
    c2.Stdout = os.Stdout
    _ = c2.Start()
    _ = c1.Run()
    _ = c2.Wait()
}


// Read the output by line 
func readByRowExists() {
    cmd := exec.Command("ls", "-h")
    stdout, _ := cmd.StdoutPipe()
    cmd.Start()
    reader := bufio.NewReader(stdout)
    for {
        line, err := reader.ReadString('\n')
        line = strings.TrimSpace(line)
        if err != nil || io.EOF == err {
            break
        }
        log.Println(line)
    }
    cmd.Wait()
}