Data commit

Task/Truncate-a-file/D/truncate-a-file.d

@@ -0,0 +1,22 @@
+import std.file, std.exception;
+
+void truncateFile(in string name, in size_t newSize) {
+    if (!exists(name) || !isFile(name))
+        throw new Exception("File not found.");
+
+    auto size = getSize(name);
+    if (size <= newSize)
+        throw new Exception(
+            "New size must be smaller than original size.");
+
+    auto content = cast(ubyte[])read(name, newSize);
+    if (content.length != newSize)
+        throw new Exception("Reading file failed.");
+
+    write(name, content);
+    enforce(getSize(name) == newSize);
+}
+
+void main() {
+    truncateFile("truncate_test.txt", 0);
+}