<?php $file = file('text.txt'); $fp = fopen('text.txt', 'w'); foreach($file as $line){ fwrite($fp, preg_replace('/,/', '=', $line, 1)); } fclose($fp); ?>
<?php $target_lines = file('1.txt'); $new_lines = preg_replace('/,/', '=', $target_lines, 1); file_put_contents('1.txt', implode('', $new_lines)); ?>