如何在Golang中使用未知参数执行系统命令

Question

I have a bunch of systems commands which are somwhat similar to appending new content to a file. I wrote a simple script to execute system commands, which works well if there are single words like 'ls' , 'date' etc. But if the command is greater than that, program dies.

The following is the code

package main

import (
    "fmt"
    "os/exec"
    "sync"
)

func exe_cmd(cmd string, wg *sync.WaitGroup) {
    fmt.Println(cmd)
    c = cmd.Str
    out, err := exec.Command(cmd).Output()
    if err != nil {
        fmt.Println("error occured")
        fmt.Printf("%s", err)
    }
    fmt.Printf("%s", out)
    wg.Done()
}

func main() {
    wg := new(sync.WaitGroup)
    wg.Add(3)

    x := []string{"echo newline >> foo.o", "echo newline >> f1.o", "echo newline >> f2.o"}
    go exe_cmd(x[0], wg)
    go exe_cmd(x[1], wg)
    go exe_cmd(x[2], wg)

    wg.Wait()
}

The following is the error i see

exec: "echo newline >> foo.o": executable file not found in $PATHexec: 
"echo newline >> f2.o": executable file not found in $PATHexec: 
"echo newline >> f1.o": executable file not found in $PATH 

I guess, this may be due to, not sending cmds and arguments seperately ( http://golang.org/pkg/os/exec/#Command ) . I am wondering how to subvert this , since I dunno how many arguments will be there in my command which needs to be executed.

Answer 1

I found a relatively decent way to achieve the same .

out, err := exec.Command("sh","-c",cmd).Output()

Works for me until now. Still finding better ways to achieve the same.

Edit1:

Finally a easier and efficient (atleast so far) way to do would be like this

func exe_cmd(cmd string, wg *sync.WaitGroup) {
  fmt.Println("command is ",cmd)
  // splitting head => g++ parts => rest of the command
  parts := strings.Fields(cmd)
  head := parts[0]
  parts = parts[1:len(parts)]

  out, err := exec.Command(head,parts...).Output()
  if err != nil {
    fmt.Printf("%s", err)
  }
  fmt.Printf("%s", out)
  wg.Done() // Need to signal to waitgroup that this goroutine is done
}

Thanks to variadic arguments in go and people that pointed that out to me :)