Add script to change codestyle

Author: TysonAndre

convert_codestyle.php

@@ -0,0 +1,32 @@
+<?php
+
+function print_usage_and_exit(string $msg = '') {
+    global $argv;
+    fprintf(STDERR, "%sUsage: %s pathname.php\nConverts fooBar to foo_bar in variable names\n", $msg ? $msg . "\n" : '', $argv[0]);
+    exit(1);
+}
+
+function convert_codestyle() {
+    global $argv;
+    if (count($argv) !== 2) {
+        print_usage_and_exit();
+    }
+    $path = $argv[1];
+    if (!file_exists($path)) {
+        print_usage_and_exit("File '$path' does not exist");
+    }
+    $contents = file_get_contents($path);
+    // Conservatively replace fooBar, but not fooBAR or fooB
+    $new_contents = preg_replace_callback('@(\$)([a-z][A-Za-z0-9]*([A-Z][a-z0-9]+)+)\b@', function(array $args) : string {
+        list($prefix, $msg) = $args;
+        return $args[1] . preg_replace_callback('@[A-Z][a-z0-9]@', function(array $inner_args) {
+
+            $msg = $inner_args[0];
+            assert(strlen($msg) === 2);
+            return '_' . strtolower($msg[0]) . $msg[1];
+        }, $args[2]);
+    }, $contents);
+    echo $new_contents;
+}
+
+convert_codestyle();