1 files changed, 81 insertions, 0 deletions
diff --git a/lib/play/command.go b/lib/play/command.go
new file mode 100644
index 00000000..2cbed88e
--- /dev/null
+++ b/lib/play/command.go
@@ -0,0 +1,81 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+package play
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"time"
+)
+
+type command struct {
+	buf       *bytes.Buffer
+	execGoRun *exec.Cmd
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+	pid       chan int
+}
+
+func newCommand(req *Request, workingDir string) (cmd *command, err error) {
+	const defCommandTimeout = 30 * time.Second
+
+	cmd = &command{
+		buf: &bytes.Buffer{},
+		pid: make(chan int, 1),
+	}
+	var ctxParent = context.Background()
+	cmd.ctx, cmd.ctxCancel = context.WithTimeout(ctxParent, defCommandTimeout)
+
+	var userHomeDir string
+
+	userHomeDir, err = os.UserHomeDir()
+	if err != nil {
+		return nil, fmt.Errorf(`newCommand: %w`, err)
+	}
+
+	cmd.execGoRun = exec.CommandContext(cmd.ctx, `go`, `run`, `-race`, `.`)
+	cmd.execGoRun.Env = append(cmd.execGoRun.Env, `CGO_ENABLED=1`)
+	cmd.execGoRun.Env = append(cmd.execGoRun.Env, `HOME=`+userHomeDir)
+	cmd.execGoRun.Env = append(cmd.execGoRun.Env, `PATH=/usr/bin:/usr/local/bin`)
+	cmd.execGoRun.Dir = workingDir
+	cmd.execGoRun.Stdout = cmd.buf
+	cmd.execGoRun.Stderr = cmd.buf
+	cmd.execGoRun.WaitDelay = 100 * time.Millisecond
+
+	return cmd, nil
+}
+
+// run the command using [exec.Command.Start] and [exec.Command.Wait].
+// The Start method is used to get the process ID.
+// When the Start or Wait failed, it will write the error or ProcessState
+// into the last line of out.
+func (cmd *command) run() (out []byte) {
+	defer cmd.ctxCancel()
+
+	var err = cmd.execGoRun.Start()
+	if err != nil {
+		cmd.buf.WriteString("\n" + err.Error() + "\n")
+		goto out
+	}
+
+	cmd.pid <- cmd.execGoRun.Process.Pid
+
+	err = cmd.execGoRun.Wait()
+	if err != nil {
+		var errExit *exec.ExitError
+		if errors.As(err, &errExit) {
+			cmd.buf.WriteString("\n" + errExit.ProcessState.String() + "\n")
+		} else {
+			cmd.buf.WriteString("\n" + err.Error() + "\n")
+		}
+	}
+out:
+	out = cmd.buf.Bytes()
+	return out
+}