Method write

/**
 * File write
 *
 * Whilst this function accepts a reference, the underlying fwrite
 * will do a copy! This will roughly double the memory allocation for
 * any write you do. Specifying chunked will get around this by only
 * writing in specific chunk sizes. This defaults to 8192 which is a
 * sane number to use most of the time (change the default with
 * JStream::set('chunksize', newsize);)
 * Note: This doesn't support gzip/bzip2 writing like reading does
 *
 * @param   string   $string  Reference to the string to write.
 * @param   integer  $length  Length of the string to write.
 * @param   integer  $chunk   Size of chunks to write in.
 *
 * @return  boolean
 *
 * @link    https://www.php.net/manual/en/function.fwrite.php
 * @since   1.7.0
 */
public function write(&$string, $length = 0, $chunk = 0)
{
    if (!$this->fh) {
        $this->setError(Text::_('JLIB_FILESYSTEM_ERROR_STREAMS_FILE_NOT_OPEN'));
        return false;
    }
    // If the length isn't set, set it to the length of the string.
    if (!$length) {
        $length = \strlen($string);
    }
    // If the chunk isn't set, set it to the default.
    if (!$chunk) {
        $chunk = $this->chunksize;
    }
    $retval = true;
    // Capture PHP errors
    $php_errormsg = '';
    $track_errors = ini_get('track_errors');
    ini_set('track_errors', true);
    $remaining = $length;
    $start = 0;
    do {
        // If the amount remaining is greater than the chunk size, then use the chunk
        $amount = $remaining > $chunk ? $chunk : $remaining;
        $res = fwrite($this->fh, substr($string, $start), $amount);
        // Returns false on error or the number of bytes written
        if ($res === false) {
            // Returned error
            $this->setError($php_errormsg);
            $retval = false;
            $remaining = 0;
        } elseif ($res === 0) {
            // Wrote nothing?
            $remaining = 0;
            $this->setError(Text::_('JLIB_FILESYSTEM_ERROR_NO_DATA_WRITTEN'));
        } else {
            // Wrote something
            $start += $amount;
            $remaining -= $res;
        }
    } while ($remaining);
    // Restore error tracking to what it was before.
    ini_set('track_errors', $track_errors);
    // Return the result
    return $retval;
}