improve CGI exit code fetching

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

Former-commit-id: d5dc759452e5be776500e265c8f466465c285ec3

core/cgi.go

@@ -26,6 +26,7 @@ func setupInitialCGIEnv(safePath string) []string {
 
 // generateCGIEnv takes a Client, and Request object, uses the global constant slice and generates a full set of CGI environment variables
 func generateCGIEnv(client *Client, request *Request) []string {
+	// Append
 	env := append(cgiEnv, "REMOTE_ADDR="+client.IP())
 	env = append(env, "QUERY_STRING="+request.Query())
 	env = append(env, "SCRIPT_NAME="+request.Path().Relative())
@@ -69,7 +70,7 @@ func ExecuteCGIScript(client *Client, request *Request) *errors.Error {
 			return
 		}
 
-		// Get process group id
+		// Get process group id.
 		pgid, err := syscall.Getpgid(cmd.Process.Pid)
 		if err != nil {
 			SystemLog.Fatalf(pgidNotFoundErrStr)
@@ -82,26 +83,19 @@ func ExecuteCGIScript(client *Client, request *Request) *errors.Error {
 		}
 	}()
 
-	// Wait for command to finish, get exit code
+	// Wait for command to finish
 	err = cmd.Wait()
-	exitCode := 0
 	if err != nil {
-		// Error, try to get exit code
-		exitError, ok := err.(*exec.ExitError)
-		if ok {
-			waitStatus := exitError.Sys().(syscall.WaitStatus)
-			exitCode = waitStatus.ExitStatus()
-		} else {
+		// Attempt to get exit code from error
+		var exitCode int
+		switch err.(type) {
+		case *exec.ExitError:
+			exitCode = err.(*exec.ExitError).Sys().(syscall.WaitStatus).ExitStatus()
+		default:
 			exitCode = 1
 		}
-	} else {
-		// No error! Get exit code directly from command process state
-		waitStatus := cmd.ProcessState.Sys().(syscall.WaitStatus)
-		exitCode = waitStatus.ExitStatus()
-	}
 
-	// Non-zero exit code? Return error
-	if exitCode != 0 {
+		// Log and return
 		SystemLog.Errorf(cgiExecuteErrStr, request.Path().Absolute(), exitCode)
 		return errors.NewError(CGIExitCodeErr)
 	}