分享经常用到的21个PHP函数代码段
下面介绍的是,在PHP 开发中,经常用到的21个函数代码段,当我们用到的时候,就可以直接用了。
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 ); ?
?? ??? ?} ?
?? ??? ??? ?else{
?? ??? ??? ?return? true;
?? ??? ?}
?? ?}
?? ?else{ ?
?? ??? ?return? 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 foo ?
echo?? $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 user ?
foreach? ( $xml ->user? as?? $user ) ?
{ ?
//access attribute ?
echo?? $user [ 'id' ], ' '; ?
//subnodes are accessed by -> operator ?
echo?? $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']; ?
?? ?}
?? ?//to check ip? is?? pass?? from? proxy
?? ?elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR'])) { ?
?? ??? ?$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('Actionscrip'=> 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 $limit ?
??????? if ( 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 false ?
?? ?if ( file_exists ( $destination ) && ! $overwrite ) {? return? false; } ?
??????? //vars ?
??????? $valid_files? =? array (); ?
??????? //if files were passed in… ?
??????? if ( is_array ( $files )) { ?
?????? ??? ?//cycle through each file ?
?????? ??? ?foreach ( $files?? as?? $file ) { ?
?????? ??? ??? ?//make sure the file exists ?
?????? ??? ??? ?if ( 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 files ?
?????? ??? ?foreach ( $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 exists ?
?????? ??? ?return?? 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 archive ?
?? ?if? ( $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 ?
} ?
到这,21个经常用到的PHP函数代码段,就大家介绍完了。希望对你有帮助。