Script that recursively strips the UTF-8 Byte Order Mark (BOM) from matching files in a given directory. BOMs are bad in PHP, especially when using output buffering or namespaces. This script helps fixing your codebase.

fix_utf8_bom.php

<?php

/**
 * Remove BOM from a single file
 *
 * @param string $filename
 * @return bool
 */
function stripUtf8BomFromFile($filename) {
    $bom = pack('CCC', 0xEF, 0xBB, 0xBF);
    $file = @fopen($filename, "r");
    $hasBOM = fread($file, 3) === $bom;
    fclose($file);

    if ($hasBOM) {
        $contents = file_get_contents($filename);
        file_put_contents($filename, substr($contents, 3));
    }

    return $hasBOM;
}

/**
 * Removes BOM from all matching files in a directory
 *
 * @param string $path Path to search in
 * @param string $exclude Dirs to exclude from search
 * @param string $file_pattern File name pattern, e.g. *.php
 * @param bool $recursive Whether to do a recursive search
 * @param bool $verbose Whether to print fixed files
 * @return array Path names of all fixed files
 */
function stripUtf8BomFromFiles($path, $file_pattern = "*", $exclude = ".|..",
                               $recursive = true, $verbose = true) {

    if (false !== $file_pattern && !function_exists('fnmatch')) {
        die(
            'Required function fnmatch is not available. Please upgrade to ' .
            'PHP >= 5.3.0 on Windows or disable pattern matching by ' .
            'passing in false.'
        );
    }

    $path = rtrim($path, "/")."/";
    $dir = opendir($path);
    $exclude_array = explode("|", $exclude);

    $files = array();
    while (false !== ($filename = readdir($dir))) {
        if (!in_array(strtolower($filename), $exclude_array)) {
            if (is_dir($path.$filename."/") && $recursive) {
                $result[] = stripUtf8BomFromFiles(
                    $path.$filename."/",
                    $file_pattern,
                    $exclude,
                    $recursive,
                    $verbose
                );
            } elseif (false === $file_pattern || fnmatch($file_pattern, $filename)) {
                if (stripUtf8BomFromFile($path.$filename)) {
                    if ($verbose) { printf("fixed %s\n", $path.$filename); }
                    $files[] = $path.$filename;
                }
            }
        }
    }

    return $files;
}

// Example: Strips BOM from all php files in the current dir and subdirs
$files = stripUtf8BomFromFiles(".", "*.php");