Initial commit

internal/runner/doc.go

@@ -0,0 +1,3 @@
+// Package runner executes command definitions by dispatching builtins
+// or starting external programs in new processes.
+package runner

internal/runner/runner.go

@@ -0,0 +1,26 @@
+package runner
+
+import (
+	"os"
+	"os/exec"
+
+	"gosh/internal/builtins"
+	"gosh/internal/command"
+)
+
+func cmd(def command.Definition) *exec.Cmd {
+	cmd := exec.Command(def.Name(), def.Arguments()...)
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	return cmd
+}
+
+// Exec runs the provided command definition immediately. It is a thin wrapper
+// around Resolve for convenience and backward compatibility.
+func Exec(def command.Definition) error {
+	if builtin, found := builtins.Lookup(def.Name()); found {
+		return builtin(def.Arguments())
+	}
+	return cmd(def).Run()
+}