Writing to Files

Writing to Files

file_put_contents('file.txt', ''> This text file contains\nsome random text. <'');

Writing to files is as easy as reading from themif you are using PHP 5 or higher. Then, the function file_put_contents() writes data directly to a file, and this is binary-safe. After calling the function, the file is closed. The code writes data into a file.

Writing Data into a File (file_put_contents.php)

<?php
  file_put_contents('file.txt',
    ''> This text file contains\nsome random text.
      <'');
  echo 'File written.';
?>

However, the preceding code overwrites the existing file. If you want to append data (therefore emulating file mode a), you first have to read in the file's data.

Appending Data to a File (file_append_contents.php)

<?php
  function file_append_contents($filename, $data) {
    $olddata = @file_get_contents($filename);
    return file_put_contents($filename,
      ''$olddata$data'');
  }

  file_append_contents('file.txt',
    "\n> This text file contains\neven more random
      text. <");
  echo 'Data appended to file';
?>

TIP It is even easier to provide a third parameter to file_put_contents() to append data instead of overwriting files: file_put_contents($filename, $data, FILE_ APPEND);

However, this all fails when a PHP version below 5.0.0 is used because the function file_put_contents() does not exist in earlier versions. It is, however, possible to emulate the behavior of file_put_contents() for older PHP versions. This works similarly to reading from a file with fopen(), fgets(), and fclose(). For writing, just one more function is required: fwrite() writes data to a file handle. The following code implements this approach. Using function_exists(), you can check whether the function file_put_contents() already exists. If not, you can write it.

Using file_put_contents() with All Relevant PHP Versions (file_put_contents_compatible.php)

<?php
  if (!function_exists('file_put_contents')) {
    function file_put_contents($filename, $content)
      {
      if ($fp = @fopen($filename, 'w')) {
        $result = fwrite($fp, $content);
        fclose($fp);
        return $result;
      } else {
        return false;
      }
    }
  }

  file_put_contents('file.txt',
    "\n> This text file contains\nsome random text.
       <");
  echo 'Data written to file.';
?>