fwrite()

fwrite() is a PHP native function that writes a string to an open file pointer. It returns the number of bytes written, or false on failure. fputs() is a plain alias of fwrite().

Key characteristics:

• Writing may stop before the end of the string if the stream refuses more data, so the return value should be checked against strlen() of the data for reliability
• An optional length parameter caps the number of bytes written, even if the string is longer
• Binary-safe, and works identically on files, pipes, and sockets

fwrite() requires the file pointer to have been opened in a writable mode, such as 'w', 'a', or 'r+', with fopen(). For writing an entire string at once without manually managing a handle, file_put_contents() is more convenient.

<?php

    $fp = fopen('/tmp/test.txt', 'w');
    if ($fp) {
        fwrite($fp, 'PHP rocks!');
        fclose($fp);
    }

?>

Documentation

See Also

• Filesystem functions

Related

• fopen()
• fclose()
• fread()
• file_put_contents()
• File
• Stream
• Writeable
• Resource Leak