update main add inputs and outputs

main.go

@@ -1,7 +1,40 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"os"
+	"time"
+)
 
 func main() {
-	fmt.Println("Hello, World!")
+	username := readInputs()
+	fmt.Printf("username is %s\n", username)
+
+	err := writeOutputs("time", time.Now().Format("2006-01-02 15:04:05"))
+	if err != nil {
+		panic(err)
+	}
+}
+
+func readInputs() string {
+	username := os.Getenv("INPUT_USERNAME")
+	return username
+}
+
+func writeOutputs(k, v string) (err error) {
+	msg := fmt.Sprintf("%s=%s", k, v)
+	outputFilepath := os.Getenv("GITHUB_OUTPUT")
+	f, err := os.OpenFile(outputFilepath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if cErr := f.Close(); cErr != nil && err == nil {
+			err = cErr
+		}
+	}()
+	if _, err = f.Write([]byte(msg)); err != nil {
+		return
+	}
+	return
 }