在编写代码的时候有个神奇的汇总是好的！下面这里收集了 10+ PHP 代码片段，可以帮助你开发 PHP 项目。这些 PHP 片段对于 PHP 初学者也非常有帮助，非常容易学习，让我们开始学习吧～

一.php中截取中文字符串

<?php

< ?php

//截取中文字符串

function mysubstr($str, $start, $len) {

$tmpstr = "";

$strlen = $start + $len;

for($i = 0; $i < $strlen; $i++) {

if(ord(substr($str, $i, 1)) > 0xa0) {

$tmpstr .= substr($str, $i, 2);

$i++;

} else

$tmpstr .= substr($str, $i, 1);

}

return $tmpstr;

}

?>

2. 截取utf8编码的多字节字符串

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<?php

< ?php

//截取utf8字符串

function utf8Substr($str, $from, $len)

{

return preg_replace('#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$from.'}'.

'((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$len.'}).*#s',

'$1',$str);

}

?>

二.php curl通过代理获取数据

$curl=curl_init();

curl_setopt($curl, CURLOPT_URL, ";);

curl_setopt($curl, CURLOPT_USERAGENT, 'Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:20.0) Gecko/20100101 Firefox/20.0');

curl_setopt($curl, CURLOPT_REFERER, ';);

curl_setopt($curl, CURLOPT_POST, true);

curl_setopt($curl, CURLOPT_POSTFIELDS, http_build_query($param));

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

curl_setopt($curl, CURLOPT_HTTPPROXYTUNNEL, true);

curl_setopt($curl, CURLOPT_PROXYAUTH, CURLAUTH_BASIC);

curl_setopt($curl, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);

curl_setopt($curl, CURLOPT_PROXY, "180.186.11.121");

curl_setopt($curl, CURLOPT_PROXYPORT, "37211");

curl_setopt($curl, CURLOPT_PROXYUSERPWD, "taras:taras-ss5");

$result=curl_exec($curl);

三.php获取中文字符串的首字符拼音字母

$str="这是一个测试程序1";

echo getFirstCharCode($str);

function getFirstCharCode($str){

$str= iconv("UTF-8","gb2312", $str);

$targetChar='*';

$i=0;

while($i<strlen($str) ) {

$tmp=bin2hex(substr($str,$i,1));

if($tmp>='B0'){ //汉字的开始

$t=getLetter(hexdec(bin2hex(substr($str,$i,2))));

$targetChar=$t==-1 ? '*' : $t ;

//printf("%c",$t==-1 ? '*' : $t );

break;

//$i+=2;

}

else{

$targetChar=substr($str,$i,1);

break;

//printf("%s",substr($str,$i,1));

//$i++;

}

}

if(is_numeric($targetChar)){

return chr($targetChar);

}

else{

return $targetChar;

}

}

四.PHP使用curl伪造IP地址和header信息

curl虽然功能强大，但是只能伪造$_SERVER["HTTP_X_FORWARDED_FOR"]，对于大多数IP地址检测程序来说，$_SERVER["REMOTE_ADDR"]很难被伪造：首先是client.php的代码

然后是server.php

五.sphinx 增量索引实现实例

六.curl 添加cookie伪造登陆抓取数据

<?php

header("Content-type:text/html;Charset=utf8");

$ch =curl_init();

curl_setopt($ch,CURLOPT_URL,';);

$header = array();

//curl_setopt($ch,CURLOPT_POST,true);

//curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);

curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);

curl_setopt($ch,CURLOPT_HEADER,true);

curl_setopt($ch,CURLOPT_HTTPHEADER,$header);

curl_setopt($ch,CURLOPT_COOKIE,'B=115.100.62.7.1401937092035530; bdshare_firstime=1401937092199; __myutma=122328856.1548793539.1401937093.1408503164.1408694138.69;');

$content = curl_exec($ch);

echo "<pre>";print_r(curl_error($ch));echo "</pre>";

echo "<pre>";print_r(curl_getinfo($ch));echo "</pre>";

echo "<pre>";print_r($header);echo "</pre>";

echo "</br>",$content;

七.php curl 上传文件

//如果php文件是utf8编码，系统是GBK编码，那么就需要转下编码，要不然Php在系统中找不到这个文件

$file = realpath(mb_convert_encoding('测试图片.JPG','GBK','utf8'));

$file = realpath('temp.jpg'); //要上传的文件

$fields['f'] = '@'.$file; // 前面加@符表示上传图片

$ch =curl_init();

curl_setopt($ch,CURLOPT_URL,';);

curl_setopt($ch,CURLOPT_POST,true);

curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);

curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);

$content = curl_exec($ch);

echo $content;

八.php+shell检测文件类型

function checkFileType($filename){

//文件头

$_typecode = array(

'3780',//PDF

'8075',//.docx,.xlsx,.pptx,.potx,.vsdx,.odt

'208207',//.doc,.xls,.ppt,.vsd,.pot,.wps,.dps,.et

);

$file = fopen($filename, "rb");

//contents = stream_get_contents($file);

//$contents = fread($file, filesize($filename));

$bin = fread($file, 2); //只读2字节

fclose($file);

$strInfo = @unpack("C2chars", $bin);// C为无符号整数，网上搜到的都是c，为有符号整数，这样会产生负数判断不正常

$typeCode = intval($strInfo['chars1'].$strInfo['chars2']);

exec("file $filename",$output,$return_var);//用linux系统命令file判断上传文件的类型,主要是判断txt,rtf文件类型

$pattern = '/text,/';//rtf和txt文档用file检测都会被检测为text

$_count = preg_match($pattern,strrchr($output[0],":"));

echo $typeCode;

if(in_array($typeCode,$_typecode) || $_count == 1) {

return true;

}else{

return false;

}

}

九.获取用户真实的IP

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;

}

十.禁止特定的IP访问你的网站

if ( !file_exists('blocked_ips.txt') ) {

$deny_ips = array(

'127.0.0.1',

'192.168.1.1',

'83.76.27.9',

'192.168.1.163'

);

} else {

$deny_ips = file('blocked_ips.txt');

}

// read user ip adress:

$ip = isset($_SERVER['REMOTE_ADDR']) ? trim($_SERVER['REMOTE_ADDR']) : '';

// search current IP in $deny_ips array

if ( (array_search($ip, $deny_ips))!== FALSE ) {

// address is blocked:

echo 'Your IP adress ('.$ip.') was blocked!';

exit;

}