round trip a message to the backend that updates the terminal fe component

pkg/shellexec/shellexec.go

@@ -0,0 +1,52 @@
+// Copyright 2024, Command Line Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package shellexec
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"syscall"
+
+	"github.com/creack/pty"
+	"github.com/wavetermdev/thenextwave/pkg/util/shellutil"
+)
+
+func RunSimpleCmdInPty(ecmd *exec.Cmd) ([]byte, error) {
+	ecmd.Env = os.Environ()
+	shellutil.UpdateCmdEnv(ecmd, shellutil.WaveshellEnvVars(shellutil.DefaultTermType))
+	cmdPty, cmdTty, err := pty.Open()
+	if err != nil {
+		return nil, fmt.Errorf("opening new pty: %w", err)
+	}
+	pty.Setsize(cmdPty, &pty.Winsize{Rows: shellutil.DefaultTermRows, Cols: shellutil.DefaultTermCols})
+	ecmd.Stdin = cmdTty
+	ecmd.Stdout = cmdTty
+	ecmd.Stderr = cmdTty
+	ecmd.SysProcAttr = &syscall.SysProcAttr{}
+	ecmd.SysProcAttr.Setsid = true
+	ecmd.SysProcAttr.Setctty = true
+	err = ecmd.Start()
+	cmdTty.Close()
+	if err != nil {
+		cmdPty.Close()
+		return nil, err
+	}
+	defer cmdPty.Close()
+	ioDone := make(chan bool)
+	var outputBuf bytes.Buffer
+	go func() {
+		// ignore error (/dev/ptmx has read error when process is done)
+		defer close(ioDone)
+		io.Copy(&outputBuf, cmdPty)
+	}()
+	exitErr := ecmd.Wait()
+	if exitErr != nil {
+		return nil, exitErr
+	}
+	<-ioDone
+	return outputBuf.Bytes(), nil
+}