我相信很多人的lamp環境都是直接復制一堆參數安裝進去的，這里有可能成功，也有可能失敗，如果是新手，估計要碰到各種錯誤，就算安裝成功，也未必知道那些參數是干嘛的，反正裝進去能用就行。

我當初開始的時候也是這樣， 完全一臉懵逼，直到我后來進修了( C語言，Linux，Linux系統編程，計算機原理等 )才能玩轉服務器配置，理解原理。

本文通過一個經典的驗證碼功能，告訴你如何按需安裝擴展!!!

要封裝一個php的驗證碼類庫，那么需要gd擴展的支持，由于我之前的php是精簡編譯安裝的，沒有gd庫的支持，所以要先安裝php的gd庫

要想成功安裝gd庫，需要安裝很多的依賴: zlib, png, jpeg, libiconv, freetype

1，zlib我之前在安裝 php memcache的擴展時候，已經安裝過了

2，安裝png

wget http://prdownloads.sourceforge.net/libpng/libpng-1.5.4.tar.gz?download

mv 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，安裝jpeg

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

tar xf jpegsrc.v9b.tar.gz

cd jpeg-9b/

./configure

make && sudo make install

4，安裝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，安裝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，到了最關鍵的地方了，安裝php gd擴展?

切換到php原碼包下? ext/gd? 這個目錄

>先執行phpize外掛模塊(?/usr/local/php54/bin/phpize? )

>./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

?

開始封裝php驗證碼庫，最后效果

1 <?php 2 3 class Captcha { 4 //驗證碼字符個數 5 protected $num; 6 //寬度 7 protected $width; 8 //高度 9 protected $height; 10 //資源 11 protected $im; 12 //類型: 1:純數字, 2:純字母 3:數字與字母混合 13 protected $codeType; 14 //生成的驗證碼字符串 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 = $_height; 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( "暫時沒有其他的驗證碼類型,你可以繼承這個類來添加額" ); 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 $charString .= 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 ); 66 } 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( "不支持的填充類型" ); 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 //創建畫布/背景 111 $this->createCanvas(); 112 //填充畫布顏色 113 $this->fillCanvas( 1 ); 114 //填充干擾元素 115 $this->fillDisturb(); 116 //填充驗證碼 117 $this->drawCodeString(); 118 //顯示驗證碼 119 $this->renderImage(); 120 } 121 } 122 123 $capt = new Captcha(); 124 //echo $capt->codeString . PHP_EOL; 125 $capt->render(); 126 ?>

?

小結：

1，復習類庫的封裝

2，理解擴展安裝原理?

??

轉載于:https://www.cnblogs.com/ghostwu/p/8472125.html

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