在前面的例子中,我們看看產生外部進程。 當需要一個執行的Go進程可存取的外部進程時,我們就可以這樣做。有時只是想用另一個(可能是非Go)完全替換當前的Go進程。可使用Go的經典exec
函式來實現。
在下面的例子將執行ls
命令。 Go需要一個我們想要執行的二進位制的絕對路徑,所以將使用exec.LookPath
來找到它(可能是/bin/ls
)。
所有的範例程式碼,都放在
F:\worksp\golang
目錄下。安裝Go程式設計環境請參考:/2/23/798.html
execing-processes.go
的完整程式碼如下所示 -
package main
import "syscall"
import "os"
import "os/exec"
func main() {
// For our example we'll exec `ls`. Go requires an
// absolute path to the binary we want to execute, so
// we'll use `exec.LookPath` to find it (probably
// `/bin/ls`).
binary, lookErr := exec.LookPath("ls")
if lookErr != nil {
panic(lookErr)
}
// `Exec` requires arguments in slice form (as
// apposed to one big string). We'll give `ls` a few
// common arguments. Note that the first argument should
// be the program name.
args := []string{"ls", "-a", "-l", "-h"}
// `Exec` also needs a set of [environment variables](environment-variables)
// to use. Here we just provide our current
// environment.
env := os.Environ()
// Here's the actual `syscall.Exec` call. If this call is
// successful, the execution of our process will end
// here and be replaced by the `/bin/ls -a -l -h`
// process. If there is an error we'll get a return
// value.
execErr := syscall.Exec(binary, args, env)
if execErr != nil {
panic(execErr)
}
}
執行上面程式碼,將得到以下輸出結果 -
此程式僅限在 Linux 類系統上執行。