diff --git a/bundle.php b/bundle.php
index 84116cd..a88f3a9 100755
--- a/bundle.php
+++ b/bundle.php
@@ -6,36 +6,58 @@ function line(string $text): void
     echo $text . PHP_EOL;
 }
 
-if (count($argv) < 2) {
-    line('Usage: bundle.php <file>');
+if (count($argv) < 3) {
+    line('Usage: bundle.php <inFile> <outFile>');
     exit(1);
 }
-$targetFile = $argv[1];
-if (!file_exists($targetFile)) {
-    line('File not found: ' . $targetFile);
+$fromFile = $argv[1];
+if (!file_exists($fromFile)) {
+    line('File not found: ' . $fromFile);
+    exit(1);
+}
+$toFile = $argv[2];
+if (file_exists($toFile)) {
+    line('File already exists: ' . $toFile);
     exit(1);
 }
 
-function getIncludes(string $file): array
+function getLineIncludeFile(string $line): false|string
 {
-    $content = file_get_contents($file);
-    $files = [];
-    foreach (explode("\n", $content) as $line) {
-        if (str_starts_with($line, 'include')) {
-            $line = "include 'test.include.php';";
-            preg_match("/include\s+'([^']+)'/", $line, $matches);
-            $files[] = $matches[1];
+    if (str_starts_with($line, 'include')) {
+        preg_match("/include\s+'([^']+)'/", $line, $matches);
+        return $matches[1];
+    }
+    return false;
+}
+
+function getAllLines(string $file): iterable
+{
+    $handle = fopen($file, 'r');
+    while (!feof($handle)) {
+        yield fgets($handle);
+    }
+    fclose($handle);
+}
+
+function replaceIncludes(string $file, int $depth = 0): iterable
+{
+    foreach (getAllLines($file) as $line) {
+        $includeFile = getLineIncludeFile($line);
+        if ($includeFile) {
+            yield from replaceIncludes($includeFile, $depth + 1);
+        } else {
+            if ($depth > 0 && str_starts_with($line, '<?php')) continue;
+            if (empty(trim($line))) continue;
+            yield $line;
         }
     }
-    return $files;
 }
 
-var_dump(getIncludes($targetFile));
-
-function buildIncludeTree(string $file): array
-{
-    $includes = getIncludes($file);
-    foreach ($includes as $include) {
-
-    }
-}
\ No newline at end of file
+$lines = replaceIncludes($fromFile);
+$toFileHandle = fopen($toFile, 'w');
+foreach ($lines as $line) {
+    fwrite($toFileHandle, $line);
+    chmod($toFile, 0755);
+}
+fwrite($toFileHandle, PHP_EOL);
+fclose($toFileHandle);
\ No newline at end of file
diff --git a/test.include.php b/test.include.php
index 5b9a833..f9c482a 100644
--- a/test.include.php
+++ b/test.include.php
@@ -1,3 +1,5 @@
 <?php
 
-echo 'test.include' . PHP_EOL;
\ No newline at end of file
+include 'test2.include.php';
+
+echo 'test.include' . PHP_EOL;
diff --git a/test2.include.php b/test2.include.php
new file mode 100644
index 0000000..8ed5ea5
--- /dev/null
+++ b/test2.include.php
@@ -0,0 +1,3 @@
+<?php
+
+echo 'test2.include' . PHP_EOL;