1 files changed, 33 insertions, 0 deletions
diff --git a/internal/app/copy.go b/internal/app/copy.go
new file mode 100644
index 00000000..bf90bfea
--- /dev/null
+++ b/internal/app/copy.go
@@ -0,0 +1,33 @@
+package app
+
+import (
+	"io"
+	"os"
+)
+
+func copyFile(dst, src string) error {
+	srcD, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if srcD.Close() != nil {
+			// unreachable
+			panic("src file closed prematurely")
+		}
+	}()
+
+	dstD, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if dstD.Close() != nil {
+			// unreachable
+			panic("dst file closed prematurely")
+		}
+	}()
+
+	_, err = io.Copy(dstD, srcD)
+	return err
+}