A practical php verification code function, php verification code_PHP tutorial

A practical php verification code function, php verification code

The examples in this article share several php verification code functions for everyone, they are very practical, the specific content is as follows

Code segment one: Simple php verification code function

<&#63;php
 
 function code(){
 
 $im = imagecreatetruecolor(100, 40);
 
 $black = imagecolorallocate($im, 0, 0, 0);
 
 $white = imagecolorallocate($im, 255, 255, 255);
 
 
 
 imagefill($im,0,0,$white);
 
 $strarr=array_merge(range(0,9),range(a,z),range(A,Z));
 
 shuffle($strarr);
 
 $str=join(array_slice($strarr,0,4));
 
 $mm=rand(0,40);
 
 $aaa=rand(0,0);
 
 $bbb=rand(0,255);
 
 $ccc=rand(0,255);
 
 $color1=imagecolorallocate($im,$aaa,$bbb,$ccc);
 
 imagestring($im,5,$mm,10,$str,$color1);
 
 for($i=0;$i<700;$i++){
 
   $aa=rand(0,255);
 
   $bb=rand(0,255);
 
   $cc=rand(0,255);
 
 $color=imagecolorallocate($im,$aa,$bb,$cc);
 
   $a=rand(0,100);
 
   $b=rand(0,40);
 
   imagesetpixel($im,$a,$b,$color);
 
 }
 
 for($t=0;$t<3;$t++){
 
   $a1=rand(0,255);
 
   $b1=rand(0,255);
 
   $c1=rand(0,255);
 
 $color2=imagecolorallocate($im,$a1,$b1,$c1);
 
   $a2=rand(0,100);
 
   $b2=rand(0,40);
 
   $a3=rand(0,100);
 
   $b3=rand(0,40);
 
   imageline($im,$a2,$b2,$b3,$b3,$color2);
 
 }
 
 
 
 header("content-type:image/png");
 
 imagepng($im);
 
 }
 
 code() ;
 
&#63;>

Code segment two:php verification code function

function _code($_code_length = 4, $_width = 75, $_height = 25){
 for($i=0;$i<$_code_length;$i++){
  $_nmsg .= dechex(mt_rand(0,15));
 }
 $_SESSION["code"] = $_nmsg;

 $_img = imagecreatetruecolor($_width, $_height);

 $_white = imagecolorallocate($_img, 250, 250, 250);

 imagefill($_img, 0, 0, $_white);

 $_gray = imagecolorallocate($_img, 196, 196, 196);

 imagerectangle($_img, 0, 0, $_width-1, $_height-1, $_gray);

 for ($i=0; $i < 6; $i++) { 
  $_md_color = imagecolorallocate($_img, mt_rand(200,255), mt_rand(200,255), mt_rand(200,255));
  imageline($_img, mt_rand(0,$_width), mt_rand(0, $_height),mt_rand(0,$_width), mt_rand(0, $_height), $_md_color);
 }

 for ($i=0; $i < 50; $i++) { 
  $_md_color = imagecolorallocate($_img, mt_rand(200,255), mt_rand(200,255), mt_rand(200,255));
  imagestring($_img, 1, mt_rand(1,$_width-5), mt_rand(1, $_height-5), "*", $_md_color);
 }

 for ($i=0; $i < $_code_length ; $i++) { 
  $_md_color = imagecolorallocate($_img, mt_rand(0,102), mt_rand(0,102), mt_rand(0,102));
  imagestring($_img, 5, $i * $_width/$_code_length+ mt_rand(1, 10), mt_rand(1, $_height/2), $_SESSION["code"][$i], $_md_color);
 }

 header("Content-Type:image/png");

 imagepng($_img);

 imagedestroy($_img);
}

Code segment three:php image verification code function

/*@ captcha()函数的功能：生成验证码
 * @ 可自定义参数：
 * @ $width 图片宽度，默认80
 * @ $high 高度，默认25
 * @ $num 验证码个数，默认4个
 * @ $line_num 随机画线条的个数，默认10
 * @ $snow_num 随机雪花的数量，默认50
 */
function captcha($width=80,$high=25,$num=4,$line_num=10,$snow_num=50){
 header('Content-Type:image/png');
 session_start();
 //生成随机数字＋字母
 for($a = 0;$a < $num;$a++){
  $code .= dechex(mt_rand(0, 15));//dechex — 十进制转换为十六进制
 }
 //把生成的验证码保存在SESSION超级全局数组中
 $_SESSION['captcha'] = $code;
 //创建画布
 $img = imagecreatetruecolor($width,$high);
 //填充背景色为白色
 $backcolor = imagecolorallocate($img, '255', '255', '255');
 imagefill($img, '0', '0', $backcolor);
 //添加黑色边框
 $bordercolor = imagecolorallocate($img, 0, 0, 0);
 imagerectangle($img, 0, 0, $width-1, $high-1, $bordercolor);
 //随机画线条
 for($i=0;$i<$line_num;$i++){
  imageline($img, mt_rand(0, $width*0.1), mt_rand(0, $high), mt_rand($width*0.9, $width), mt_rand(0, $high),
  imagecolorallocate($img, mt_rand(150, 255), mt_rand(150, 255), mt_rand(150, 255)));
 }
 //随机打雪花
 for ($i=0;$i<$snow_num;$i++){
  imagechar($img,1, mt_rand(0, $width), mt_rand(0, $high),'*',
  imagecolorallocate($img, mt_rand(200, 255), mt_rand(200, 255), mt_rand(200, 255)));
 }
 //画验证码
 for ($b = 0;$b < strlen($_SESSION['captcha']);$b++){
  imagechar($img,5, $b*$width/$num+mt_rand(5,10), mt_rand(2, $high/2),$_SESSION['captcha'][$b],
  imagecolorallocate($img, mt_rand(10, 150), mt_rand(10, 150), mt_rand(0, 100)));
 }
 ob_clean();//清空输出缓冲区
 imagepng($img);
 imagedestroy($img);
}

The above are three highly referenced PHP verification code functions. I hope it will be helpful to everyone in learning PHP programming.

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