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()函數(shù)的功能：生成驗(yàn)證碼
 * @ 可自定義參數(shù)：
 * @ $width 圖片寬度，默認(rèn)80
 * @ $high 高度，默認(rèn)25
 * @ $num 驗(yàn)證碼個(gè)數(shù)，默認(rèn)4個(gè)
 * @ $line_num 隨機(jī)畫(huà)線條的個(gè)數(shù)，默認(rèn)10
 * @ $snow_num 隨機(jī)雪花的數(shù)量，默認(rèn)50
 */
function captcha($width=80,$high=25,$num=4,$line_num=10,$snow_num=50){
 header('Content-Type:image/png');
 session_start();
 //生成隨機(jī)數(shù)字＋字母
 for($a = 0;$a < $num;$a++){
  $code .= dechex(mt_rand(0, 15));//dechex — 十進(jìn)制轉(zhuǎn)換為十六進(jìn)制
 }
 //把生成的驗(yàn)證碼保存在SESSION超級(jí)全局?jǐn)?shù)組中
 $_SESSION['captcha'] = $code;
 //創(chuàng)建畫(huà)布
 $img = imagecreatetruecolor($width,$high);
 //填充背景色為白色
 $backcolor = imagecolorallocate($img, '255', '255', '255');
 imagefill($img, '0', '0', $backcolor);
 //添加黑色邊框
 $bordercolor = imagecolorallocate($img, 0, 0, 0);
 imagerectangle($img, 0, 0, $width-1, $high-1, $bordercolor);
 //隨機(jī)畫(huà)線條
 for($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)));
 }
 //隨機(jī)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)));
 }
 //畫(huà)驗(yàn)證碼
 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();//清空輸出緩沖區(qū)
 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.