21个常用的PHP函数代码段
作者：[网上资料 ]
给大家分享21个常用的PHP函数代码段，内容如下：
1. PHP可阅读随机字符串
此代码将创建一个可阅读的字符串，使其更接近词典中的单词，实用且具有密码验证功能。
/***************@length – length of random string (must be a multiple of 2)**************/function readable_random_string($length = 6){$conso=array(“b”,”c”,”d”,”f”,”g”,”h”,”j”,”k”,”l”,“m”,”n”,”p”,”r”,”s”,”t”,”v”,”w”,”x”,”y”,”z”);$vocal=array(“a”,”e”,”i”,”o”,”u”);$password=”";srand ((double)microtime()*1000000);$max = $length/2;for($i=1; $i<=$max; $i++){$password.=$conso[rand(0,19)];$password.=$vocal[rand(0,4)];}return $password;}
2. PHP生成一个随机字符串
如果不需要可阅读的字符串，使用此函数替代，即可创建一个随机字符串，作为用户的随机密码等。
/**************@l – length of random string*/function generate_rand($l){$c= “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789″;srand((double)microtime()*1000000);for($i=0; $i<$l; $i++) {$rand.= $c[rand()%strlen($c)];}return $rand;}
3. PHP编码电子邮件地址
使用此代码，可以将任何电子邮件地址编码为 html 字符实体，以防止被垃圾邮件程序收集。
function encode_email($email=’info@domain.com’, $linkText=’Contact Us’, $attrs =’class=”emailencoder”‘ ){// remplazar aroba y puntos$email = str_replace(‘@’, ‘@’, $email);$email = str_replace(‘.’, ‘.’, $email);$email = str_split($email, 5);
$linkText = str_replace(‘@’, ‘@’, $linkText);$linkText = str_replace(‘.’, ‘.’, $linkText);$linkText = str_split($linkText, 5);
$part1 = ‘<a href=”ma’;$part2 = ‘ilto:’;$part3 = ‘” ‘. $attrs .’ >’;$part4 = ‘</a>’;
$encoded = ‘<script type=”text/javascript”>’;$encoded .= “document.write(‘$part1′);”;$encoded .= “document.write(‘$part2′);”;foreach($email as $e){$encoded .= “document.write(‘$e’);”;}$encoded .= “document.write(‘$part3′);”;foreach($linkText as $l){$encoded .= “document.write(‘$l’);”;}$encoded .= “document.write(‘$part4′);”;$encoded .= ‘</script>’;
return $encoded;}
4. PHP验证邮件地址
电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。
function is_valid_email($email, $test_mx = false){if(eregi(“^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$”, $email))if($test_mx){list($username, $domain) = split(“@”, $email);return getmxrr($domain, $mxrecords);}elsereturn true;elsereturn false;}
5. PHP列出目录内容
function list_files($dir){if(is_dir($dir)){if($handle = opendir($dir)){while(($file = readdir($handle)) !== false){if($file != “.” && $file != “..” && $file != “Thumbs.db”){echo ‘<a target=”_blank” href=”‘.$dir.$file.’”>’.$file.’</a><br>’.”\n”;}}closedir($handle);}}}
6. PHP销毁目录
删除一个目录，包括它的内容。
/******@dir – Directory to destroy*@virtual[optional]- whether a virtual directory*/function destroyDir($dir, $virtual = false){$ds = DIRECTORY_SEPARATOR;$dir = $virtual ? realpath($dir) : $dir;$dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir;if (is_dir($dir) && $handle = opendir($dir)){while ($file = readdir($handle)){if ($file == ‘.’ || $file == ‘..’){continue;}elseif (is_dir($dir.$ds.$file)){destroyDir($dir.$ds.$file);}else{unlink($dir.$ds.$file);}}closedir($handle);rmdir($dir);return true;}else{return false;}}
7. PHP解析 JSON 数据
与大多数流行的 Web 服务如 twitter 通过开放 API 来提供数据一样，它总是能够知道如何解析 API 数据的各种传送格式，包括 JSON，XML 等等。
$json_string=’{“id”:1,”name”:”foo”,”email”:”foo@foobar.com”,”interest”:["wordpress","php"]} ‘;$obj=json_decode($json_string);echo $obj->name; //prints fooecho $obj->interest[1]; //prints php
8. PHP解析 XML 数据
//xml string$xml_string=”<?xml version=’1.0′?><users><user id=’398′><name>Foo</name><email>foo@bar.com</name></user><user id=’867′><name>Foobar</name><email>foobar@foo.com</name></user></users>”;
//load the xml string using simplexml$xml = simplexml_load_string($xml_string);
//loop through the each node of userforeach ($xml->user as $user){//access attributeecho $user['id'], ‘ ‘;//subnodes are accessed by -> operatorecho $user->name, ‘ ‘;echo $user->email, ‘<br />’;}
9. PHP创建日志缩略名
创建用户友好的日志缩略名。
function create_slug($string){$slug=preg_replace(‘/[^A-Za-z0-9-]+/’, ‘-’, $string);return $slug;}
10. PHP获取客户端真实 IP 地址
该函数将获取用户的真实 IP 地址，即便他使用代理服务器。
function getRealIpAddr(){if (!emptyempty($_SERVER['HTTP_CLIENT_IP'])){$ip=$_SERVER['HTTP_CLIENT_IP'];}elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))//to check ip is pass from proxy{$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];}else{$ip=$_SERVER['REMOTE_ADDR'];}return $ip;}
11. PHP强制性文件下载
为用户提供强制性的文件下载功能。
/*********************@file – path to file*/function force_download($file){if ((isset($file))&&(file_exists($file))) {header(“Content-length: “.filesize($file));header(‘Content-Type: application/octet-stream’);header(‘Content-Disposition: attachment; filename=”‘ . $file . ‘”‘);readfile(“$file”);} else {echo “No file selected”;}}
12. PHP创建标签云
function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 ){$minimumCount = min( array_values( $data ) );$maximumCount = max( array_values( $data ) );$spread = $maximumCount – $minimumCount;$cloudHTML = ”;$cloudTags = array();
$spread == 0 && $spread = 1;
foreach( $data as $tag => $count ){$size = $minFontSize + ( $count – $minimumCount )* ( $maxFontSize – $minFontSize ) / $spread;$cloudTags[] = ‘<a style=”font-size: ‘ . floor( $size ) . ‘px’. ‘” href=”#” title=”\” . $tag .‘\’ returned a count of ‘ . $count . ‘”>’. htmlspecialchars( stripslashes( $tag ) ) . ‘</a>’;}
return join( “\n”, $cloudTags ) . “\n”;}/****************************** Sample usage ***/$arr = Array(‘Actionscript’ => 35, ‘Adobe’ => 22, ‘Array’ => 44, ‘Background’ => 43,‘Blur’ => 18, ‘Canvas’ => 33, ‘Class’ => 15, ‘Color Palette’ => 11, ‘Crop’ => 42,‘Delimiter’ => 13, ‘Depth’ => 34, ‘Design’ => 8, ‘Encode’ => 12, ‘Encryption’ => 30,‘Extract’ => 28, ‘Filters’ => 42);echo getCloud($arr, 12, 36);
13. PHP寻找两个字符串的相似性
PHP 提供了一个极少使用的 similar_text 函数，但此函数非常有用，用于比较两个字符串并返回相似程度的百分比。
similar_text($string1, $string2, $percent);//$percent will have the percentage of similarity
14. PHP在应用程序中使用 Gravatar 通用头像
随着 WordPress 越来越普及，Gravatar 也随之流行。由于 Gravatar 提供了易于使用的 API，将其纳入应用程序也变得十分方便。
/*******************@email – Email address to show gravatar for*@size – size of gravatar*@default – URL of default gravatar to use*@rating – rating of Gravatar(G, PG, R, X)*/function show_gravatar($email, $size, $default, $rating){echo ‘<img src=”http://www.gravatar.com/avatar.php?gravatar_id=’.md5($email).‘&default=’.$default.’&size=’.$size.’&rating=’.$rating.’” width=”‘.$size.’px”height=”‘.$size.’px” />’;}
15. PHP在字符断点处截断文字
所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
// Original PHP code by Chirp Internet: www.chirp.com.au// Please acknowledge use of this code by including this header.function myTruncate($string, $limit, $break=”.”, $pad=”…”) {// return with no change if string is shorter than $limitif(strlen($string) <= $limit)return $string;
// is $break present between $limit and the end of the string?if(false !== ($breakpoint = strpos($string, $break, $limit))) {if($breakpoint < strlen($string) – 1) {$string = substr($string, 0, $breakpoint) . $pad;}}return $string;}/***** Example ****/$short_string=myTruncate($long_string, 100, ‘ ‘);
16. PHP文件 Zip 压缩
/* creates a compressed zip file */function create_zip($files = array(),$destination = ”,$overwrite = false) {//if the zip file already exists and overwrite is false, return falseif(file_exists($destination) && !$overwrite) { return false; }//vars$valid_files = array();//if files were passed in…if(is_array($files)) {//cycle through each fileforeach($files as $file) {//make sure the file existsif(file_exists($file)) {$valid_files[] = $file;}}}//if we have good files…if(count($valid_files)) {//create the archive$zip = new ZipArchive();if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) {return false;}//add the filesforeach($valid_files as $file) {$zip->addFile($file,$file);}//debug//echo ‘The zip archive contains ‘,$zip->numFiles,’ files with a status of ‘,$zip->status;
//close the zip — done!$zip->close();
//check to make sure the file existsreturn file_exists($destination);}else{return false;}}/***** Example Usage ***/$files=array(‘file1.jpg’, ‘file2.jpg’, ‘file3.gif’);create_zip($files, ‘myzipfile.zip’, true);
17. PHP解压缩 Zip 文件
/***********************@file – path to zip file*@destination – destination directory for unzipped files*/function unzip_file($file, $destination){// create object$zip = new ZipArchive() ;// open archiveif ($zip->open($file) !== TRUE) {die (’Could not open archive’);}// extract contents to destination directory$zip->extractTo($destination);// close archive$zip->close();echo ‘Archive extracted to directory’;}
18. PHP为 URL 地址预设 http 字符串
有时需要接受一些表单中的网址输入，但用户很少添加 http:// 字段，此代码将为网址添加该字段。
if (!preg_match(“/^(http|ftp):/”, $_POST['url'])) {$_POST['url'] = ‘http://’.$_POST['url'];}
19. PHP将网址字符串转换成超级链接
该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。
function makeClickableLinks($text) {$text = eregi_replace(‘(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)’,‘<a href=”\1″>\1</a>’, $text);$text = eregi_replace(‘([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)’,‘\1<a href=”http://\2″>\2</a>’, $text);$text = eregi_replace(‘([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})’,‘<a href=”mailto:\1″>\1</a>’, $text);
return $text;}
20. PHP调整图像尺寸
创建图像缩略图需要许多时间，此代码将有助于了解缩略图的逻辑。
/***********************@filename – path to the image*@tmpname – temporary path to thumbnail*@xmax – max width*@ymax – max height*/function resize_image($filename, $tmpname, $xmax, $ymax){$ext = explode(“.”, $filename);$ext = $ext[count($ext)-1];
if($ext == “jpg” || $ext == “jpeg”)$im = imagecreatefromjpeg($tmpname);elseif($ext == “png”)$im = imagecreatefrompng($tmpname);elseif($ext == “gif”)$im = imagecreatefromgif($tmpname);
$x = imagesx($im);$y = imagesy($im);
if($x <= $xmax && $y <= $ymax)return $im;
if($x >= $y) {$newx = $xmax;$newy = $newx * $y / $x;}else {$newy = $ymax;$newx = $x / $y * $newy;}
$im2 = imagecreatetruecolor($newx, $newy);imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y);return $im2;}
21. PHP检测 ajax 请求
大多数的 JavaScript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == ‘xmlhttprequest’){//If AJAX Request Then}else{//something else}
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1. PHP可阅读随机字符串
此代码将创建一个可阅读的字符串，使其更接近词典中的单词，实用且具有密码验证功能。
/***************@length – length of random string (must be a multiple of 2)**************/function readable_random_string($length = 6){$conso=array(“b”,”c”,”d”,”f”,”g”,”h”,”j”,”k”,”l”,“m”,”n”,”p”,”r”,”s”,”t”,”v”,”w”,”x”,”y”,”z”);$vocal=array(“a”,”e”,”i”,”o”,”u”);$password=”";srand ((double)microtime()*1000000);$max = $length/2;for($i=1; $i<=$max; $i++){$password.=$conso[rand(0,19)];$password.=$vocal[rand(0,4)];}return $password;}
2. PHP生成一个随机字符串
如果不需要可阅读的字符串，使用此函数替代，即可创建一个随机字符串，作为用户的随机密码等。
/**************@l – length of random string*/function generate_rand($l){$c= “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789″;srand((double)microtime()*1000000);for($i=0; $i<$l; $i++) {$rand.= $c[rand()%strlen($c)];}return $rand;}
3. PHP编码电子邮件地址
使用此代码，可以将任何电子邮件地址编码为 html 字符实体，以防止被垃圾邮件程序收集。
function encode_email($email=’info@domain.com’, $linkText=’Contact Us’, $attrs =’class=”emailencoder”‘ ){// remplazar aroba y puntos$email = str_replace(‘@’, ‘@’, $email);$email = str_replace(‘.’, ‘.’, $email);$email = str_split($email, 5);
$linkText = str_replace(‘@’, ‘@’, $linkText);$linkText = str_replace(‘.’, ‘.’, $linkText);$linkText = str_split($linkText, 5);
$part1 = ‘<a href=”ma’;$part2 = ‘ilto:’;$part3 = ‘” ‘. $attrs .’ >’;$part4 = ‘</a>’;
$encoded = ‘<script type=”text/javascript”>’;$encoded .= “document.write(‘$part1′);”;$encoded .= “document.write(‘$part2′);”;foreach($email as $e){$encoded .= “document.write(‘$e’);”;}$encoded .= “document.write(‘$part3′);”;foreach($linkText as $l){$encoded .= “document.write(‘$l’);”;}$encoded .= “document.write(‘$part4′);”;$encoded .= ‘</script>’;
return $encoded;}
4. PHP验证邮件地址
电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。
function is_valid_email($email, $test_mx = false){if(eregi(“^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$”, $email))if($test_mx){list($username, $domain) = split(“@”, $email);return getmxrr($domain, $mxrecords);}elsereturn true;elsereturn false;}
5. PHP列出目录内容
function list_files($dir){if(is_dir($dir)){if($handle = opendir($dir)){while(($file = readdir($handle)) !== false){if($file != “.” && $file != “..” && $file != “Thumbs.db”){echo ‘<a target=”_blank” href=”‘.$dir.$file.’”>’.$file.’</a><br>’.”\n”;}}closedir($handle);}}}
6. PHP销毁目录
删除一个目录，包括它的内容。
/******@dir – Directory to destroy*@virtual[optional]- whether a virtual directory*/function destroyDir($dir, $virtual = false){$ds = DIRECTORY_SEPARATOR;$dir = $virtual ? realpath($dir) : $dir;$dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir;if (is_dir($dir) && $handle = opendir($dir)){while ($file = readdir($handle)){if ($file == ‘.’ || $file == ‘..’){continue;}elseif (is_dir($dir.$ds.$file)){destroyDir($dir.$ds.$file);}else{unlink($dir.$ds.$file);}}closedir($handle);rmdir($dir);return true;}else{return false;}}
7. PHP解析 JSON 数据
与大多数流行的 Web 服务如 twitter 通过开放 API 来提供数据一样，它总是能够知道如何解析 API 数据的各种传送格式，包括 JSON，XML 等等。
$json_string=’{“id”:1,”name”:”foo”,”email”:”foo@foobar.com”,”interest”:["wordpress","php"]} ‘;$obj=json_decode($json_string);echo $obj->name; //prints fooecho $obj->interest[1]; //prints php
8. PHP解析 XML 数据
//xml string$xml_string=”<?xml version=’1.0′?><users><user id=’398′><name>Foo</name><email>foo@bar.com</name></user><user id=’867′><name>Foobar</name><email>foobar@foo.com</name></user></users>”;
//load the xml string using simplexml$xml = simplexml_load_string($xml_string);
//loop through the each node of userforeach ($xml->user as $user){//access attributeecho $user['id'], ‘ ‘;//subnodes are accessed by -> operatorecho $user->name, ‘ ‘;echo $user->email, ‘<br />’;}
9. PHP创建日志缩略名
创建用户友好的日志缩略名。
function create_slug($string){$slug=preg_replace(‘/[^A-Za-z0-9-]+/’, ‘-’, $string);return $slug;}
10. PHP获取客户端真实 IP 地址
该函数将获取用户的真实 IP 地址，即便他使用代理服务器。
function getRealIpAddr(){if (!emptyempty($_SERVER['HTTP_CLIENT_IP'])){$ip=$_SERVER['HTTP_CLIENT_IP'];}elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))//to check ip is pass from proxy{$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];}else{$ip=$_SERVER['REMOTE_ADDR'];}return $ip;}
11. PHP强制性文件下载
为用户提供强制性的文件下载功能。
/*********************@file – path to file*/function force_download($file){if ((isset($file))&&(file_exists($file))) {header(“Content-length: “.filesize($file));header(‘Content-Type: application/octet-stream’);header(‘Content-Disposition: attachment; filename=”‘ . $file . ‘”‘);readfile(“$file”);} else {echo “No file selected”;}}
12. PHP创建标签云
function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 ){$minimumCount = min( array_values( $data ) );$maximumCount = max( array_values( $data ) );$spread = $maximumCount – $minimumCount;$cloudHTML = ”;$cloudTags = array();
$spread == 0 && $spread = 1;
foreach( $data as $tag => $count ){$size = $minFontSize + ( $count – $minimumCount )* ( $maxFontSize – $minFontSize ) / $spread;$cloudTags[] = ‘<a style=”font-size: ‘ . floor( $size ) . ‘px’. ‘” href=”#” title=”\” . $tag .‘\’ returned a count of ‘ . $count . ‘”>’. htmlspecialchars( stripslashes( $tag ) ) . ‘</a>’;}
return join( “\n”, $cloudTags ) . “\n”;}/****************************** Sample usage ***/$arr = Array(‘Actionscript’ => 35, ‘Adobe’ => 22, ‘Array’ => 44, ‘Background’ => 43,‘Blur’ => 18, ‘Canvas’ => 33, ‘Class’ => 15, ‘Color Palette’ => 11, ‘Crop’ => 42,‘Delimiter’ => 13, ‘Depth’ => 34, ‘Design’ => 8, ‘Encode’ => 12, ‘Encryption’ => 30,‘Extract’ => 28, ‘Filters’ => 42);echo getCloud($arr, 12, 36);
13. PHP寻找两个字符串的相似性
PHP 提供了一个极少使用的 similar_text 函数，但此函数非常有用，用于比较两个字符串并返回相似程度的百分比。
similar_text($string1, $string2, $percent);//$percent will have the percentage of similarity
14. PHP在应用程序中使用 Gravatar 通用头像
随着 WordPress 越来越普及，Gravatar 也随之流行。由于 Gravatar 提供了易于使用的 API，将其纳入应用程序也变得十分方便。
/*******************@email – Email address to show gravatar for*@size – size of gravatar*@default – URL of default gravatar to use*@rating – rating of Gravatar(G, PG, R, X)*/function show_gravatar($email, $size, $default, $rating){echo ‘<img src=”http://www.gravatar.com/avatar.php?gravatar_id=’.md5($email).‘&default=’.$default.’&size=’.$size.’&rating=’.$rating.’” width=”‘.$size.’px”height=”‘.$size.’px” />’;}
15. PHP在字符断点处截断文字
所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
// Original PHP code by Chirp Internet: www.chirp.com.au// Please acknowledge use of this code by including this header.function myTruncate($string, $limit, $break=”.”, $pad=”…”) {// return with no change if string is shorter than $limitif(strlen($string) <= $limit)return $string;
// is $break present between $limit and the end of the string?if(false !== ($breakpoint = strpos($string, $break, $limit))) {if($breakpoint < strlen($string) – 1) {$string = substr($string, 0, $breakpoint) . $pad;}}return $string;}/***** Example ****/$short_string=myTruncate($long_string, 100, ‘ ‘);
16. PHP文件 Zip 压缩
/* creates a compressed zip file */function create_zip($files = array(),$destination = ”,$overwrite = false) {//if the zip file already exists and overwrite is false, return falseif(file_exists($destination) && !$overwrite) { return false; }//vars$valid_files = array();//if files were passed in…if(is_array($files)) {//cycle through each fileforeach($files as $file) {//make sure the file existsif(file_exists($file)) {$valid_files[] = $file;}}}//if we have good files…if(count($valid_files)) {//create the archive$zip = new ZipArchive();if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) {return false;}//add the filesforeach($valid_files as $file) {$zip->addFile($file,$file);}//debug//echo ‘The zip archive contains ‘,$zip->numFiles,’ files with a status of ‘,$zip->status;
//close the zip — done!$zip->close();
//check to make sure the file existsreturn file_exists($destination);}else{return false;}}/***** Example Usage ***/$files=array(‘file1.jpg’, ‘file2.jpg’, ‘file3.gif’);create_zip($files, ‘myzipfile.zip’, true);
17. PHP解压缩 Zip 文件
/***********************@file – path to zip file*@destination – destination directory for unzipped files*/function unzip_file($file, $destination){// create object$zip = new ZipArchive() ;// open archiveif ($zip->open($file) !== TRUE) {die (’Could not open archive’);}// extract contents to destination directory$zip->extractTo($destination);// close archive$zip->close();echo ‘Archive extracted to directory’;}
18. PHP为 URL 地址预设 http 字符串
有时需要接受一些表单中的网址输入，但用户很少添加 http:// 字段，此代码将为网址添加该字段。
if (!preg_match(“/^(http|ftp):/”, $_POST['url'])) {$_POST['url'] = ‘http://’.$_POST['url'];}
19. PHP将网址字符串转换成超级链接
该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。
function makeClickableLinks($text) {$text = eregi_replace(‘(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)’,‘<a href=”\1″>\1</a>’, $text);$text = eregi_replace(‘([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)’,‘\1<a href=”http://\2″>\2</a>’, $text);$text = eregi_replace(‘([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})’,‘<a href=”mailto:\1″>\1</a>’, $text);
return $text;}
20. PHP调整图像尺寸
创建图像缩略图需要许多时间，此代码将有助于了解缩略图的逻辑。
/***********************@filename – path to the image*@tmpname – temporary path to thumbnail*@xmax – max width*@ymax – max height*/function resize_image($filename, $tmpname, $xmax, $ymax){$ext = explode(“.”, $filename);$ext = $ext[count($ext)-1];
if($ext == “jpg” || $ext == “jpeg”)$im = imagecreatefromjpeg($tmpname);elseif($ext == “png”)$im = imagecreatefrompng($tmpname);elseif($ext == “gif”)$im = imagecreatefromgif($tmpname);
$x = imagesx($im);$y = imagesy($im);
if($x <= $xmax && $y <= $ymax)return $im;
if($x >= $y) {$newx = $xmax;$newy = $newx * $y / $x;}else {$newy = $ymax;$newx = $x / $y * $newy;}
$im2 = imagecreatetruecolor($newx, $newy);imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y);return $im2;}
21. PHP检测 ajax 请求
大多数的 JavaScript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == ‘xmlhttprequest’){//If AJAX Request Then}else{//something else}
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