Phpwind verification code

To support the. Image image function in the gd library, see php. liukang. commanualzhref. Image. php? PhpBYPHP country www. phphot. be disable error error_reporting (0); image width $ x_size60; image height $ y_size20; generate four random characters $ nmsgnum_rand (4); support secure connection? PHPwind verification code

The gd Library is required.
Image functions
See http://php.liukang.com/manual/zh/ref.image.php
// By php country www. phphot. be
// Close and report an error
Error_reporting (0 );
// Image width
$ X_size = 60;
// Image height
$ Y_size = 20;
// Generate 4 random characters
$ Nmsg = num_rand (4 );
// Is secure connection supported?
$ S = $ _ SERVER ['server _ port'] = '000000 '? 1:0;
// Use cookies to record random codes
// Expire = 0 cookie will expire after the session ends (usually closed by the browser.
SetCookie ('CK _ num', md5 ($ nmsg), 0, '/', ', $ S );
// Create an image (canvas) with a width of 60*20)
$ Aimg = imagecreate ($ x_size, $ y_size );
// Set the background color of the image
$ Back = imagecolorallocate ($ aimg, 255,255,255 );
// Set the font color
$ Border = imagecolorallocate ($ aimg, 0, 0, 0 );
// Fill in the white rectangle area of 59*19 from
Imagefilledrectangle ($ aimg, 0, 0, $ x_size-1, $ y_size-1, $ back );
// Draw a black rectangle border of 59*19 from
Imagerectangle ($ aimg, 0, 0, $ x_size-1, $ y_size-1, $ border );

For ($ I = 0; $ I
// Write on the image
ImageString ($ aimg, 5, $ I * $ x_size/4 + 3, 2, $ nmsg [$ I], $ border );
}
Header ("Content-type: image/png ");
Imagepng ($ aimg );
Imagedestroy ($ aimg); exit;
Function num_rand ($ lenth ){
// Play a random number generator seed
// Php starts from 4.2.0. this parameter becomes optional. If this parameter is null, it is set to the value at any time.
Mt_srand (double) microtime () * 1000000 );
// Generate a string with four random numbers
For ($ I = 0; $ I <$ lenth; $ I ++ ){
$ Randval. = mt_rand (0, 9 );
}
// Use md5 encryption for strings containing four digits. the length is 32 characters.
// From 3 to 32 characters, take the string with the length of $ lenth from the minimum number or the maximum number of 32-$ lenth
$ Randval = substr (md5 ($ randval), mt_rand (0, 32-$ lenth), $ lenth );
Return $ randval;
}
?>