A Practical php verification code function, php Verification Code

A Practical php verification code function, php Verification Code

The examples in this article share several php verification code functions, which are very practical. The specific content is as follows:

Code snippet 1:Simple php Verification Code Function

<?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() ; ?>

Code Segment 2: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 snippet 3:Php image Verification Code Function

/* @ Captcha () function: generate a Verification Code * @ customizable parameter: * @ $ width image width. The default value is 80 * @ $ high, the default value is 25 * @ $ num. The default value is 4 * @ $ line_num. The default value is 10 * @ $ snow_num, default 50 */function captcha ($ width = 80, $ high = 25, $ num = 4, $ line_num = 10, $ snow_num = 50) {header ('content-Type: image/png '); session_start (); // generate random numbers + letters for ($ a = 0; $ a <$ num; $ a ++) {$ code. = dechex (mt_rand (0, 15 )); // dechex-decimal to hexadecimal} // Save the generated verification code in the SESSION super Global Array $ _ SESSION ['captcha '] = $ code; // create a canvas $ img = imagecreatetruecolor ($ width, $ high); // fill in the background color in white $ backcolor = imagecolorallocate ($ img, '123456', '123456 ', '000000'); imagefill ($ img, '0', '0', $ backcolor); // Add a black border $ bordercolor = imagecolorallocate ($ img, 0, 0, 0); imagerectangle ($ img, 0, 0, $ width-1, $ high-1, $ bordercolor); // randomly draw a line 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);} // random snowflake 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);} // draw a verification code 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 (); // clear the output buffer imagepng ($ img); imagedestroy ($ img );}

The above are three pieces of php verification code functions with high reference, and hope to help you learn php programming.