tasks a-s

Task/Remove-lines-from-a-file/D/remove-lines-from-a-file.d

@@ -0,0 +1,25 @@
+import std.stdio, std.file, std.string;
+
+void main() {
+    deleteLines("deleteline_test.txt", 1, 2);
+}
+
+void deleteLines(string name, int start, int num)
+in {
+    assert(start > 0, "Line counting must start at 1");
+} body {
+    start--;
+
+    if (!exists(name) || !isFile(name))
+        throw new FileException("File not found");
+
+    auto lines = readText(name).splitLines();
+    if (lines.length < start + num)
+        throw new Exception("Can't delete lines past the end of file!");
+
+    auto f = File(name, "w");
+    foreach (int i, line; lines) {
+        if (start > i || i >= start + num)
+            f.writeln(line);
+    }
+}