Ubuntu: Install the gd extension of php step by encapsulating the verification code library.

Ubuntu: Install the gd extension of php step by encapsulating the verification code library.

I believe that many people directly copy a bunch of parameters to install the lamp environment. The installation may be successful or fail. If you are a newbie, you may encounter various errors. Even if the installation is successful, you may not know what the parameters are for. You just need to use the anti-formal dress.

This was also the case at the beginning, and I was totally overwhelmed. I had to study later (C language, Linux, Linux system programming, computer principles, etc.) before I could play with server configuration and understand the principles.

This article uses a classic verification code function to show you how to install extensions on demand !!!

To encapsulate a php Verification Code Class Library, the support for gd extension is required. Because my previous php was compiled and installed in a simplified manner without the support of the gd library, you must first install the php gd library.

To successfully install the gd library, you need to install many dependencies: zlib, png, jpeg, libiconv, and freetype.

1. zlib I have installed the php memcache extension before.

2. Install png

Wget http://prdownloads.sourceforge.net/libpng/libpng-1.5.4.tar.gz? Download

Music libpng-1.5.4.tar.gz \? Download libpng-1.5.4.tar.gz

Tar xf libpng-1.5.4.tar.gz

Cd libpng-1.5.4/

./Configure

Make & sudo make install

3. Install jpeg

Wget http://www.ijg.org/files/jpegsrc.v9b.tar.gz

Tar xf release src.v9b.tar.gz

Cd jpeg-9b/

./Configure

Make & sudo make install

4. Install libiconv

Wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.15.tar.gz

Tar xf libiconv-1.15.tar.gz

Cd libiconv-1.15/

./Configure

Make & sudo make install

5. Install freeType

Wget https://download.savannah.gnu.org/releases/freetype/freetype-2.9.tar.gz

Tar xf freetype-2.9.tar.gz

Cd freetype-2.9/

./Configure

Make & sudo make install

6. Install the php gd extension.

Switch to the ext/gd directory under the php original code package

> Execute the phpize plug-in Module (/usr/local/php54/bin/phpize) first)

>. /Configure -- with-php-config =/usr/local/php54/bin/php-config-with-png-dir -- with-freetype-dir -- with-jpeg-dir- with-zlib-dir -- with-gd

> Make & sudo make install

 

Start encapsulating the php verification code library.

1 <? Php 2 3 class Captcha {4 // number of characters in the Verification Code 5 protected $ num; 6 // width 7 protected $ width; 8 // height 9 protected $ height; 10 // resource 11 protected $ im; 12 // type: 1: pure number, 2: Pure Letter 3: Mixed number and letter 13 protected $ codeType; 14 // The generated verification code string 15 protected $ codeString; 16 17 public function _ construct ($ _ num = 4, $ _ width = 150, $ _ height = 50, $ _ codeType = 3) {18 $ this-> num = $ _ num; 19 $ this-> width = $ _ width; 20 $ this-> height = $ _ heig Ht; 21 $ this-> codeType =$ _ codeType; 22 $ this-> codeString = $ this-> createCodeString (); 23} 24 25 public function _ get ($ name) {26 if ($ name = 'codestring') {27 return $ this-> codeString; 28} 29 return false; 30} 31 32 protected function createCodeString () {33 switch ($ this-> codeType) {34 case 1: 35 $ code = $ this-> createNumCode (); 36 break; 37 case 2: 38 $ code = $ this-> createCharCode (); 39 Break; 40 case 3: 41 $ code = $ this-> createNumCharCode (); 42 break; 43 default: 44 die ("no other verification code types currently, you can inherit this class to add "); 45} 46 return $ code; 47} 48 49 protected function createNumCode () {50 $ numString = join ("", range (0, 9); 51 return substr (str_shuffle ($ numString), 0, $ this-> num); 52} 53 54 protected function createCharCode () {55 $ charString = join ("", range ('A', 'z'); 56 $ charStr Ing. = strtoupper ($ charString); 57 return substr (str_shuffle ($ numString), 0, $ this-> num); 58} 59 60 protected function createNumCharCode () {61 $ numCharString = join ("", range (0, 9); 62 $ charString = join ("", range ('A', 'z ')); 63 $ charString. = strtoupper ($ charString); 64 $ mixedString = $ numCharString. $ charString; 65 return substr (str_shuffle ($ mixedString), 0, $ this-> num); 6 6} 67 68 protected function createCanvas () {69 $ this-> im = imagecreatetruecolor ($ this-> width, $ this-> height ); 70} 71 72 protected function fillCanvas ($ type) {73 switch ($ type) {74 case 1: 75 $ color = imagecolorallocate ($ this-> im, mt_rand (0,150 ), mt_rand (0,150), mt_rand (0,150); 76 break; 77 case 2: 78 $ color = imagecolorallocate ($ this-> im, mt_rand (150,255), mt_rand (150,255) ), Mt_rand (150,255); 79 break; 80 default: 81 die ("unsupported Filling Type"); 82 break; 83} 84 imagefill ($ this-> im, 0, 0, $ color); 85} 86 87 protected function drawCodeString () {88 for ($ I = 0; $ I <$ this-> num; $ I ++) {89 $ fontColor = imagecolorallocate ($ this-> im, mt_rand (0,255), mt_rand (0,255), mt_rand (0,255 )); 90 $ char = $ this-> codeString [$ I]; 91 $ x = ($ I * ($ this-> width)/$ this-> num) + Mt_rand (5, 10); 92 $ y = mt_rand (0, $ this-> height/2) + mt_rand (5, 10 ); 93 imagestring ($ this-> im, 5, $ x, $ y, $ char, $ fontColor); 94} 95} 96 97 protected function renderImage () {98 header ("Content-type: image/png"); 99 imagepng ($ this-> im); 100} 101 102 protected function fillDisturb () {103 for ($ I = 0; $ I <100; $ I ++) {104 $ color = imagecolorallocate ($ this-> im, mt_rand (0,255 ), Mt_rand (0,255), mt_rand (0,255); 105 imagesetpixel ($ this-> im, mt_rand (0, $ this-> width), mt_rand (0, $ this-> height), $ color); 106} 107} 108 109 public function render () {110 // create a canvas/background 111 $ this-> createCanvas (); 112 // fill the canvas color 113 $ this-> fillCanvas (1); 114 // fill the interference element 115 $ this-> fillDisturb (); 116 // fill in the verification code 117 $ this-> drawCodeString (); 118 // display the verification code 119 $ this-> renderImage (); 120} 121 122 $ capt = new Captcha (); 124 // echo $ capt-> codeString. PHP_EOL; 125 $ capt-> render (); 126?>

 

Summary:

1. Review the encapsulation of the Class Library

2. Understand the principle of extended Installation