创建一个在Go中运行任意shell命令的函数

Question

I am trying to create a generic function in go that takes in input a shell command (with arguments) and execute it.

Note the shell commands may have a different number of arguments.

I understand that the exec.Command() in Go takes as input the format ("ls", "-la", "/var") for the command + arguments.

This code snipped below doesn't work:

func exe_cmd(commandarray []string) {
var shell_command string = ""
for i := 0; i < len(commandarray); i++ {
                  shell_command = shell_command + " " + commandarray[i]
                  }
cmd := exec.Command(shell_command)
fmt.Println("Command is: ", shell_command)
fmt.Printf("==> Executing: %s
", strings.Join(cmd.Args, " "))
out, err := cmd.Output()
fmt.Printf("OutVar: %s
", out)
fmt.Printf("ErrVar: %s
", err)
}

func dummy() {
dummycmd := []string{"ls", "-la", "/var"}
exe_cmd(dummycmd)
}

A the end of the for the shell_command variable will contain "ls -la /var" and I am having a hard time to figure out how to form it in a way that is what the input format requires i.e. "ls", "-la", "/var"

I have also tried to set dummycmd as a variable with "ls -la /var" but I figure that was even worse if requirement is to pass it to the exec.Command in the format above.

Thoughts?

Thanks.

Answer 1

You can simply match the argument signature of the exec.Command function, which is

(name string, arg ...string)

And use the variadic syntax to pass the function argument along to exec.Command

func execCmd(name string, args ...string) {
    cmd := exec.Command(name, args...)

    fmt.Printf("Command is: %s, %s", name, args)

    out, err := cmd.Output()

    fmt.Printf("OutVar: %s
", out)
    fmt.Printf("ErrVar: %s
", err)
}

Note however, you're not invoking a shell here, so relying on any shell builtin's will fail.