问题
As per the golang documentation, go does not make a call to the system's shell when you are using exec.Command().
From the golang.org documentation on the "os/exec" package:
Unlike the "system" library call from C and other languages, the os/exec package intentionally does not invoke the system shell and does not expand any glob patterns or handle other expansions, pipelines, or redirections typically done by shells.
This presents a problem. Because of this design choice you cannot use piping when executing a command. Therefore the following code does not execute as desired.
package main
import (
"fmt"
"os/exec"
)
func main() {
exec.Command("echo", "Hello", ">>", "~/thing").Run()
cmdOut, _ := exec.Command("cat", "~/thing").Output()
fmt.Println(cmdOut)
}
Instead of printing out the contents of a file that should contain the word 'Hello,' it instead prints out a blank newline. I have tried directly invoking bash like this:
package main
import (
"fmt"
"os/exec"
)
func main() {
exec.Command("bash", "-c", "echo", "Hello", ">>", "~/thing").Run()
cmdOut, _ := exec.Command("cat", "~/thing").Output()
fmt.Println(cmdOut)
}
This, however, produces the same result as the original code. How can I directly invoke the system shell when using golang?
回答1:
The second argument should be one string. In shell command you need to pass it as one string too. Also ~ is interpreted by bash. You can safely assume that sh exists. Bash shell is not a must.
package main
import (
"fmt"
"os/exec"
)
func main() {
exec.Command("sh", "-c", "echo Hello >> ~/thing").Run()
cmdOut, _ := exec.Command("sh", "-c", "cat ~/thing").Output()
fmt.Println(cmdOut)
}
来源：https://stackoverflow.com/questions/60894355/how-to-directly-invoke-the-system-shell-in-go-golang