Home > Article > Backend Development > PHP generates verification code image program_PHP tutorial

PHP generates verification code image program_PHP tutorial

WBOYOriginal: 2016-07-13 17:10:15868browse

A PHP downloaded from a foreign website generates a verification code image code. This is more practical. We also gave an example. Friends in need can click on it and save it as PHP.

The code is as follows

Copy code

代码如下

复制代码

session_start();

if( isset($_POST['submit'])) {
if( $_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {
// Insert you code for processing the form here, e.g emailing the submission, entering it into a database.
echo 'Thank you. Your message said "'.$_POST['message'].'"';
unset($_SESSION['security_code']);
} else {
// Insert your code for showing an error message here
echo 'Sorry, you have provided an invalid security code';
}
} else {
?>

}
?>

session_start();

<🎜>if( isset($_POST['submit'])) {
if( $_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {
// Insert you code for processing the form here, e.g emailing the submission, entering it into a database.
echo 'Thank you. Your message said "'.$_POST['message'].'"';
unset($_SESSION['security_code']);
} else {
// Insert your code for showing an error message here
echo 'Sorry, you have provided an invalid security code';
}
} else {
?> }
?>

验证程序 CaptchaSecurityImages.php

代码如下

复制代码

session_start();

/*
* File: CaptchaSecurityImages.php
* Author: Simon Jarvis
* Copyright: 2006 Simon Jarvis
* Date: 03/08/06
* Updated: 07/02/07
* Requirements: PHP 4/5 with GD and FreeType libraries
* Link: http://www.white-hat-web-design.co.uk/articles/php-captcha.php
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details:
* http://www.gnu.org/licenses/gpl.html
*
*/

class CaptchaSecurityImages {

var $font = 'monofont.ttf';

function generateCode($characters) {
/* list all possible characters, similar looking characters and vowels have been removed */
$possible = '23456789bcdfghjkmnpqrstvwxyz';
$code = '';
$i = 0;
while ($i < $characters) {
$code .= substr($possible, mt_rand(0, strlen($possible)-1), 1);
$i++;
}
return $code;
}

}

$width = isset($_GET['width']) ? $_GET['width'] : '120';
$height = isset($_GET['height']) ? $_GET['height'] : '40';
$characters = isset($_GET['characters']) && $_GET['characters'] > 1 ? $_GET['characters'] : '6';

$captcha = new CaptchaSecurityImages($width,$height,$characters);

复制代码

session_start();

class CaptchaSecurityImages { var $font = 'monofont.ttf'; function generateCode($characters) {
  /* list all possible characters, similar looking characters and vowels have been removed */
  $possible = '23456789bcdfghjkmnpqrstvwxyz';
  $code = '';
  $i = 0;
  while ($i < $characters) {
   $code .= substr($possible, mt_rand(0, strlen($possible)-1), 1);
   $i++;
  }
  return $code;
} function CaptchaSecurityImages($width='120',$height='40',$characters='6') {
  $code = $this->generateCode($characters);
  /* font size will be 75% of the image height */
  $font_size = $height * 0.75;
  $image = @imagecreate($width, $height) or die('Cannot initialize new GD image stream');
  /* set the colours */
  $background_color = imagecolorallocate($image, 255, 255, 255);
  $text_color = imagecolorallocate($image, 20, 40, 100);
  $noise_color = imagecolorallocate($image, 100, 120, 180);
  /* generate random dots in background */
  for( $i=0; $i<($width*$height)/3; $i++ ) {
   imagefilledellipse($image, mt_rand(0,$width), mt_rand(0,$height), 1, 1, $noise_color);
  }
  /* generate random lines in background */
  for( $i=0; $i<($width*$height)/150; $i++ ) {
   imageline($image, mt_rand(0,$width), mt_rand(0,$height), mt_rand(0,$width), mt_rand(0,$height), $noise_color);
  }
  /* create textbox and add text */
  $textbox = imagettfbbox($font_size, 0, $this->font, $code) or die('Error in imagettfbbox function');
  $x = ($width - $textbox[4])/2;
  $y = ($height - $textbox[5])/2;
  imagettftext($image, $font_size, 0, $x, $y, $text_color, $this->font , $code) or die('Error in imagettftext function');
  /* output captcha image to browser */
  header('Content-Type: image/jpeg');
  imagejpeg($image);
  imagedestroy($image);
  $_SESSION['security_code'] = $code;
} } $width = isset($_GET['width']) ? $_GET['width'] : '120';
$height = isset($_GET['height']) ? $_GET['height'] : '40';
$characters = isset($_GET['characters']) && $_GET['characters'] > 1 ? $_GET['characters'] : '6'; $captcha = new CaptchaSecurityImages($width,$height,$characters); ?>

http://www.bkjia.com/PHPjc/629694.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/629694.htmlTechArticle一款国外网站下载的php生成验证码图片代码，这个比较实用我们还举例说明了，有需要的朋友按上面保存成php就可以用了哦。代码如下复制...

Statement：

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Previous article：PHP comes with function filtering sql injection code analysis_PHP tutorialNext article：PHP comes with function filtering sql injection code analysis_PHP tutorial

See more

PHP generates verification code image program_PHP tutorial

Related articles