add file tool

utils/file.go

@@ -0,0 +1,53 @@
+package utils
+
+import (
+	"io"
+	"os"
+	"os/exec"
+	"strconv"
+)
+
+// FileExists check file is exists
+func FileExists(path string) bool {
+	_, err := os.Stat(path)
+	if err != nil {
+		if os.IsExist(err) {
+			return true
+		}
+		return false
+	}
+	return true
+}
+
+// PidExists checkou process id is exists
+func PidExists(pid int) bool {
+	out, _ := exec.Command("kill", "-s", "0", strconv.Itoa(pid)).CombinedOutput()
+	if string(out) == "" {
+		return true // pid exist
+	}
+	return false
+}
+
+// CopyFile copy file from src to dest
+func CopyFile(srcFile, destFile string) error {
+	file, err := os.Open(srcFile)
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	dest, err := os.Create(destFile)
+	if err != nil {
+		return err
+	}
+
+	defer dest.Close()
+
+	_, err = io.Copy(dest, file)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}