PHP implementation of digital verification code and digital operation verification Code, PHP digital Verification code Operation _php Tutorial

PHP implementation of digital verification code and digital operation verification Code, PHP digital Verification code operation

In this paper, the digital Verification Code and digital operation verification Code for PHP implementation are described. Share to everyone for your reference. Specific as follows:

1. Digital Verification Code:

<?php//The first instance is a digital verification code, the most common verification code. How many numbers can be decided by yourself.  $num is the generated verification code containing several numbers getvalidate (4,60,20), function getvalidate ($num, $w, $h) {$code = "";  for ($i =0; $i < $num; $i + +) {$code. = rand (0,9); The//code variable ends with a $num number and is a string.  Inherited if a four-bit digital verification code is generated, the Header ("Content-type:image/png") can be generated with Rand (1000,9999);  $img = Imagecreate ($w, $h);//Create a picture, the length-width parameter is defined at the beginning. $black = Imagecolorallocate ($img, 0,0,0);//define Black $gray = Imagecolorallocate ($img, 200,200,200);//define Gray $bgcolor =  Imagecolorallocate ($img, 255,255,255);//Background color white Imagefill ($img, 0,0, $gray);  Imagefill ($image, ing $x, int $y, int $color), performing area fills with a color color at the coordinates x, y of the image images//to the verification code to draw the border, feel the verification code Meimei, in fact, the border is to draw him a rectangle  Imagerectangle ($img, 0,0, $w-1, $h-1, $black);//Black box/*imagestring ($image, $font, $x, $y, $s, $col) Use the col color to draw the string s to the X, y of the image represented by image (XY is the upper-left coordinate of the string), and the upper-left corner of the entire image is (0,0) if the font is 1,2,3,4,5 use the built-in font *///once to draw four numbers, so that four character positions are randomly  Strx = rand (5,10);    for ($i = 0; $i < $num; $i + +) {$strops = rand (1,6);    Imagestring ($img, 5, $strx, $strops, substr ($code, $i, 1), $black); $strx + = rand (8,12); The Strx is the horizontal axis, which needs to be added each time before the coordinates are guaranteed to not overlap. Ordinate no matter}//substr () function returns a part of the string, substr (String,start,length), the string to intercept, start position, length of the Intercept//generate a good number, the following to give some interference in the Captcha area, Prevents some tools from automatically identifying//1. Method One: Add a lot of noise to the background//imagesetpixel ($image, $x, $y, $color), draw a dot for the image image in the x, y coordinates (0,0 in the upper left corner) for ($ i = 0; $i <80; $i + +) {Imagesetpixel ($img, rand (0, $w), rand (0, $h), $black);//These points are distributed within this background}//2. Method Two: Draw a few dashed lines $style = a  Rray ($black, $gray);  Imagesetstyle ($img, $style);  Imagesetstyle ($image, $style), sets the style of the drawing line, the array of pixels $y 1 = rand (0, $h);  $y 2 = rand (0, $h);  $y 3 = rand (0, $h);  $y 4 = rand (0, $h);  Imageline ($img, 0, $y 1, $w, $y 2,img_color_styled);  Imageline ($img, 0, $y 3, $w, $y 4,img_color_styled);  Imagepng ($IMG); Imagedestroy ($img);}? >

2. Numeric Operation Verification Code:

<?phpgetvalidate (100,30), function getvalidate ($w, $h) {$img = Imagecreate ($w, $h);  $gray = Imagecolorallocate ($img, 255,255,255);  $black = Imagecolorallocate ($img, Rand (0,200), Rand (0,200), Rand (0,200));  $red = Imagecolorallocate ($img, 255, 0, 0);  $white = Imagecolorallocate ($img, 255, 255, 255);  $green = imagecolorallocate ($img, 0, 255, 0);  $blue = imagecolorallocate ($img, 0, 0, 255);  Imagefilledrectangle ($img, 0, 0, +, $black);  for ($i = 0; $i <; $i + +) {Imagesetpixel ($img, rand (0, $w), rand (0, $h), $gray);  } $num 1 = rand (1,99);  $num 2 = rand (1,99);  Imagestring ($img, 5, 5, rand (1,10), $num 1, $red);  Imagestring ($img, 5,30,rand (1,10), Getrand (), $white);  Imagestring ($img, 5,45,rand (1,10), $num 2, $green);  Imagestring ($img, 5,65,rand (1,10), "=", $blue);  Imagestring ($img, 5,80,rand (1,10), "?", $red);  Header ("Content-type:image/png");  Imagepng ($IMG); Imagedestroy ($img);}  function Getrand () {$code = rand (0,1);      Switch ($code) {case 0:return "+";    Break CasE 1:return "-";    Break  Default: # code ... break; }}?>

I hope this article is helpful to everyone's PHP programming.

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