(PECL OAuth >= 1.0.0)
OAuthProvider::generateToken — Generate a random token
$size
   [, bool $strong = false
  ] )Generates a string of pseudo-random bytes.
sizeThe desired token length, in terms of bytes.
strong
      Setting to TRUE means /dev/random will be used for
      entropy, as otherwise the non-blocking /dev/urandom is used.
      This parameter is ignored on Windows.
     
The generated token, as a string of bytes.
   If the strong parameter is TRUE, then an
   E_WARNING level error will be emitted when the
   fallback rand() implementation is used to fill
   the remaining random bytes (e.g., when not enough random data was found,
   initially).
  
Example #1 OAuthProvider::generateToken() example
<?php
$p = new OAuthProvider();
$t = $p->generateToken(4);
echo strlen($t),  PHP_EOL;
echo bin2hex($t), PHP_EOL;
?>
The above example will output something similar to:
4 b6a82c27
Note:
When not enough random data is available to the system, this function will fill the remaining random bytes using the internal PHP rand() implementation.