10个典型实用的PHP代码片段_PHP教程-php教程-PHP中文网

首页

后端开发

php教程

10个典型实用的PHP代码片段_PHP教程

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Jul 12, 2016 am 09:07 AM

php代码片段

10个典型实用的PHP代码片段

本文将介绍10个经常会用到的PHP代码片段，包括黑名单过滤、随机颜色生成器、从网上下载文件、Alexa/Google Page Rank、强制下载文件、用Email显示用户的Gravator头像、用cURL获取RSS订阅数、截取图片、检查网站是否宕机。

一、黑名单过滤

<ol class="dp-c"><li class="alt"><span><span class="keyword">function</span><span> is_spam(</span><span class="vars">$text</span><span>, </span><span class="vars">$file</span><span>, </span><span class="vars">$split</span><span> = </span><span class="string">':'</span><span>, </span><span class="vars">$regex</span><span> = false){ </span></span></li><li><span>    <span class="vars">$handle</span><span> = </span><span class="func">fopen</span><span>(</span><span class="vars">$file</span><span>, </span><span class="string">'rb'</span><span>); </span></span></li><li class="alt"><span>    <span class="vars">$contents</span><span> = </span><span class="func">fread</span><span>(</span><span class="vars">$handle</span><span>, </span><span class="func">filesize</span><span>(</span><span class="vars">$file</span><span>)); </span></span></li><li><span>    fclose(<span class="vars">$handle</span><span>); </span></span></li><li class="alt"><span>    <span class="vars">$lines</span><span> = </span><span class="func">explode</span><span>(</span><span class="string">"n"</span><span>, </span><span class="vars">$contents</span><span>); </span></span></li><li><span><span class="vars">$arr</span><span> = </span><span class="keyword">array</span><span>(); </span></span></li><li class="alt"><span><span class="keyword">foreach</span><span>(</span><span class="vars">$lines</span><span> </span><span class="keyword">as</span><span> </span><span class="vars">$line</span><span>){ </span></span></li><li><span>list(<span class="vars">$word</span><span>, </span><span class="vars">$count</span><span>) = </span><span class="func">explode</span><span>(</span><span class="vars">$split</span><span>, </span><span class="vars">$line</span><span>); </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(</span><span class="vars">$regex</span><span>) </span></span></li><li><span><span class="vars">$arr</span><span>[</span><span class="vars">$word</span><span>] = </span><span class="vars">$count</span><span>; </span></span></li><li class="alt"><span><span class="keyword">else</span><span> </span></span></li><li><span><span class="vars">$arr</span><span>[preg_quote(</span><span class="vars">$word</span><span>)] = </span><span class="vars">$count</span><span>; </span></span></li><li class="alt"><span>} </span></li><li><span>preg_match_all(<span class="string">"~"</span><span>.implode(</span><span class="string">'|'</span><span>, </span><span class="func">array_keys</span><span>(</span><span class="vars">$arr</span><span>)).</span><span class="string">"~"</span><span>, </span><span class="vars">$text</span><span>, </span><span class="vars">$matches</span><span>); </span></span></li><li class="alt"><span><span class="vars">$temp</span><span> = </span><span class="keyword">array</span><span>(); </span></span></li><li><span><span class="keyword">foreach</span><span>(</span><span class="vars">$matches</span><span>[0] </span><span class="keyword">as</span><span> </span><span class="vars">$match</span><span>){ </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(!in_array(</span><span class="vars">$match</span><span>, </span><span class="vars">$temp</span><span>)){ </span></span></li><li><span><span class="vars">$temp</span><span>[</span><span class="vars">$match</span><span>] = </span><span class="vars">$temp</span><span>[</span><span class="vars">$match</span><span>] + 1; </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(</span><span class="vars">$temp</span><span>[</span><span class="vars">$match</span><span>] >= </span><span class="vars">$arr</span><span>[</span><span class="vars">$word</span><span>]) </span></span></li><li><span><span class="keyword">return</span><span> true; </span></span></li><li class="alt"><span>} </span></li><li><span>} </span></li><li class="alt"><span><span class="keyword">return</span><span> false; </span></span></li><li><span>} </span></li><li class="alt"><span> </span></li><li><span><span class="vars">$file</span><span> = </span><span class="string">'spam.txt'</span><span>; </span></span></li><li class="alt"><span><span class="vars">$str</span><span> = </span><span class="string">'This string has cat, dog word'</span><span>; </span></span></li><li><span><span class="keyword">if</span><span>(is_spam(</span><span class="vars">$str</span><span>, </span><span class="vars">$file</span><span>)) </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">'this is spam'</span><span>; </span></span></li><li><span><span class="keyword">else</span><span> </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">'this is not spam'</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span>ab:3 </span></li><li><span>dog:3 </span></li><li class="alt"><span>cat:2 </span></li><li><span>monkey:2 </span></li></ol>

二、随机颜色生成器

<ol class="dp-c"><li class="alt"><span><span class="keyword">function</span><span> randomColor() { </span></span></li><li><span>    <span class="vars">$str</span><span> = </span><span class="string">'#'</span><span>; </span></span></li><li class="alt"><span>    <span class="keyword">for</span><span>(</span><span class="vars">$i</span><span> = 0 ; </span><span class="vars">$i</span><span> < 6 ; </span><span class="vars">$i</span><span>++) { </span></span></li><li><span>        <span class="vars">$randNum</span><span> = rand(0 , 15); </span></span></li><li class="alt"><span>        <span class="keyword">switch</span><span> (</span><span class="vars">$randNum</span><span>) { </span></span></li><li><span>            <span class="keyword">case</span><span> 10: </span><span class="vars">$randNum</span><span> = </span><span class="string">'A'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span>            <span class="keyword">case</span><span> 11: </span><span class="vars">$randNum</span><span> = </span><span class="string">'B'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li><span>            <span class="keyword">case</span><span> 12: </span><span class="vars">$randNum</span><span> = </span><span class="string">'C'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span>            <span class="keyword">case</span><span> 13: </span><span class="vars">$randNum</span><span> = </span><span class="string">'D'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li><span>            <span class="keyword">case</span><span> 14: </span><span class="vars">$randNum</span><span> = </span><span class="string">'E'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span>            <span class="keyword">case</span><span> 15: </span><span class="vars">$randNum</span><span> = </span><span class="string">'F'</span><span>; </span><span class="keyword">break</span><span>; </span></span></li><li><span>        } </span></li><li class="alt"><span>        <span class="vars">$str</span><span> .= </span><span class="vars">$randNum</span><span>; </span></span></li><li><span>    } </span></li><li class="alt"><span>    <span class="keyword">return</span><span> </span><span class="vars">$str</span><span>; </span></span></li><li><span>} </span></li><li class="alt"><span><span class="vars">$color</span><span> = randomColor(); </span></span></li></ol>

三、从网上下载文件

<ol class="dp-c"><li class="alt"><span><span>set_time_limit(0); </span></span></li><li><span><span class="comment">// Supports all file types</span><span> </span></span></li><li class="alt"><span><span class="comment">// URL Here:</span><span> </span></span></li><li><span><span class="vars">$url</span><span> = </span><span class="string">'http://somsite.com/some_video.flv'</span><span>; </span></span></li><li class="alt"><span><span class="vars">$pi</span><span> = </span><span class="func">pathinfo</span><span>(</span><span class="vars">$url</span><span>); </span></span></li><li><span><span class="vars">$ext</span><span> = </span><span class="vars">$pi</span><span>[</span><span class="string">'extension'</span><span>]; </span></span></li><li class="alt"><span><span class="vars">$name</span><span> = </span><span class="vars">$pi</span><span>[</span><span class="string">'filename'</span><span>]; </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">// create a new cURL resource</span><span> </span></span></li><li><span><span class="vars">$ch</span><span> = curl_init(); </span></span></li><li class="alt"><span> </span></li><li><span><span class="comment">// set URL and other appropriate options</span><span> </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_URL, </span><span class="vars">$url</span><span>); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_HEADER, false); </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_BINARYTRANSFER, true); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_AUTOREFERER, true); </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_FOLLOWLOCATION, true); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_RETURNTRANSFER, true); </span></span></li><li class="alt"><span> </span></li><li><span><span class="comment">// grab URL and pass it to the browser</span><span> </span></span></li><li class="alt"><span><span class="vars">$opt</span><span> = curl_exec(</span><span class="vars">$ch</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">// close cURL resource, and free up system resources</span><span> </span></span></li><li><span>curl_close(<span class="vars">$ch</span><span>); </span></span></li><li class="alt"><span> </span></li><li><span><span class="vars">$saveFile</span><span> = </span><span class="vars">$name</span><span>.</span><span class="string">'.'</span><span>.</span><span class="vars">$ext</span><span>; </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(preg_match(</span><span class="string">"/[^0-9a-z._-]/i"</span><span>, </span><span class="vars">$saveFile</span><span>)) </span></span></li><li><span><span class="vars">$saveFile</span><span> = md5(microtime(true)).</span><span class="string">'.'</span><span>.</span><span class="vars">$ext</span><span>; </span></span></li><li class="alt"><span> </span></li><li><span><span class="vars">$handle</span><span> = </span><span class="func">fopen</span><span>(</span><span class="vars">$saveFile</span><span>, </span><span class="string">'wb'</span><span>); </span></span></li><li class="alt"><span>fwrite(<span class="vars">$handle</span><span>, </span><span class="vars">$opt</span><span>); </span></span></li><li><span>fclose(<span class="vars">$handle</span><span>); </span></span></li></ol>

四、Alexa/Google Page Rank

<ol class="dp-c"><li class="alt"><span><span class="keyword">function</span><span> page_rank(</span><span class="vars">$page</span><span>, </span><span class="vars">$type</span><span> = </span><span class="string">'alexa'</span><span>){ </span></span></li><li><span><span class="keyword">switch</span><span>(</span><span class="vars">$type</span><span>){ </span></span></li><li class="alt"><span><span class="keyword">case</span><span> </span><span class="string">'alexa'</span><span>: </span></span></li><li><span><span class="vars">$url</span><span> = </span><span class="string">'http://alexa.com/siteinfo/'</span><span>; </span></span></li><li class="alt"><span><span class="vars">$handle</span><span> = </span><span class="func">fopen</span><span>(</span><span class="vars">$url</span><span>.</span><span class="vars">$page</span><span>, </span><span class="string">'r'</span><span>); </span></span></li><li><span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span><span class="keyword">case</span><span> </span><span class="string">'google'</span><span>: </span></span></li><li><span><span class="vars">$url</span><span> = </span><span class="string">'http://google.com/search?client=navclient-auto&ch=6-1484155081&features=Rank&q=info:'</span><span>; </span></span></li><li class="alt"><span><span class="vars">$handle</span><span> = </span><span class="func">fopen</span><span>(</span><span class="vars">$url</span><span>.</span><span class="string">'http://'</span><span>.</span><span class="vars">$page</span><span>, </span><span class="string">'r'</span><span>); </span></span></li><li><span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span>} </span></li><li><span><span class="vars">$content</span><span> = stream_get_contents(</span><span class="vars">$handle</span><span>); </span></span></li><li class="alt"><span>fclose(<span class="vars">$handle</span><span>); </span></span></li><li><span><span class="vars">$content</span><span> = preg_replace(</span><span class="string">"~(n|t|ss+)~"</span><span>,</span><span class="string">''</span><span>, </span><span class="vars">$content</span><span>); </span></span></li><li class="alt"><span><span class="keyword">switch</span><span>(</span><span class="vars">$type</span><span>){ </span></span></li><li><span><span class="keyword">case</span><span> </span><span class="string">'alexa'</span><span>: </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(preg_match(</span><span class="string">'~<div class="data (down|up)"><img  src="/static/imghwm/default1.png"  data-src="http://www.bkjia.com/uploads/allimg/151012/152R41955-1.jpg"  class="lazy" .+? alt="10个典型实用的PHP代码片段_PHP教程" >(.+?) </div>~im'</span><span>,</span><span class="vars">$content</span><span>,</span><span class="vars">$matches</span><span>)){ </span></span></li><li><span><span class="keyword">return</span><span> </span><span class="vars">$matches</span><span>[2]; </span></span></li><li class="alt"><span>}<span class="keyword">else</span><span>{ </span></span></li><li><span><span class="keyword">return</span><span> FALSE; </span></span></li><li class="alt"><span>} </span></li><li><span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span><span class="keyword">case</span><span> </span><span class="string">'google'</span><span>: </span></span></li><li><span><span class="vars">$rank</span><span> = </span><span class="func">explode</span><span>(</span><span class="string">':'</span><span>,</span><span class="vars">$content</span><span>); </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(</span><span class="vars">$rank</span><span>[2] != </span><span class="string">''</span><span>) </span></span></li><li><span><span class="keyword">return</span><span> </span><span class="vars">$rank</span><span>[2]; </span></span></li><li class="alt"><span><span class="keyword">else</span><span> </span></span></li><li><span><span class="keyword">return</span><span> FALSE; </span></span></li><li class="alt"><span><span class="keyword">break</span><span>; </span></span></li><li><span><span class="keyword">default</span><span>: </span></span></li><li class="alt"><span><span class="keyword">return</span><span> FALSE; </span></span></li><li><span><span class="keyword">break</span><span>; </span></span></li><li class="alt"><span>} </span></li><li><span>} </span></li><li class="alt"><span><span class="comment">// Alexa Page Rank:</span><span> </span></span></li><li><span><span class="func">echo</span><span> </span><span class="string">'Alexa Rank: '</span><span>.page_rank(</span><span class="string">'techug.com'</span><span>); </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">' '</span><span>; </span></span></li><li><span><span class="comment">// Google Page Rank</span><span> </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">'Google Rank: '</span><span>.page_rank(</span><span class="string">'techug.com'</span><span>, </span><span class="string">'google'</span><span>); </span></span></li></ol>

五、强制下载文件

<ol class="dp-c"><li class="alt"><span><span class="vars">$filename</span><span> = </span><span class="vars">$_GET</span><span>[</span><span class="string">'file'</span><span>]; </span><span class="comment">//Get the fileid from the URL</span><span> </span></span></li><li><span><span class="comment">// Query the file ID</span><span> </span></span></li><li class="alt"><span><span class="vars">$query</span><span> = sprintf(</span><span class="string">"SELECT * FROM tableName WHERE id = '%s'"</span><span>,mysql_real_escape_string(</span><span class="vars">$filename</span><span>)); </span></span></li><li><span><span class="vars">$sql</span><span> = mysql_query(</span><span class="vars">$query</span><span>); </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(mysql_num_rows(</span><span class="vars">$sql</span><span>) > 0){ </span></span></li><li><span><span class="vars">$row</span><span> = mysql_fetch_array(</span><span class="vars">$sql</span><span>); </span></span></li><li class="alt"><span><span class="comment">// Set some headers</span><span> </span></span></li><li><span>header(<span class="string">"Pragma: public"</span><span>); </span></span></li><li class="alt"><span>header(<span class="string">"Expires: 0"</span><span>); </span></span></li><li><span>header(<span class="string">"Cache-Control: must-revalidate, post-check=0, pre-check=0"</span><span>); </span></span></li><li class="alt"><span>header(<span class="string">"Content-Type: application/force-download"</span><span>); </span></span></li><li><span>header(<span class="string">"Content-Type: application/octet-stream"</span><span>); </span></span></li><li class="alt"><span>header(<span class="string">"Content-Type: application/download"</span><span>); </span></span></li><li><span>header(<span class="string">"Content-Disposition: attachment; filename="</span><span>.</span><span class="func">basename</span><span>(</span><span class="vars">$row</span><span>[</span><span class="string">'FileName'</span><span>]).</span><span class="string">";"</span><span>); </span></span></li><li class="alt"><span>header(<span class="string">"Content-Transfer-Encoding: binary"</span><span>); </span></span></li><li><span>header(<span class="string">"Content-Length: "</span><span>.</span><span class="func">filesize</span><span>(</span><span class="vars">$row</span><span>[</span><span class="string">'FileName'</span><span>])); </span></span></li><li class="alt"><span> </span></li><li><span>@readfile(<span class="vars">$row</span><span>[</span><span class="string">'FileName'</span><span>]); </span></span></li><li class="alt"><span><span class="func">exit</span><span>(0); </span></span></li><li><span>}<span class="keyword">else</span><span>{ </span></span></li><li class="alt"><span>header(<span class="string">"Location: /"</span><span>); </span></span></li><li><span><span class="func">exit</span><span>; </span></span></li><li class="alt"><span>} </span></li></ol>

六、用Email显示用户的Gravator头像

<ol class="dp-c"><li class="alt"><span><span class="vars">$gravatar_link</span><span> = </span><span class="string">'http://www.gravatar.com/avatar/'</span><span> . md5(</span><span class="vars">$comment_author_email</span><span>) . </span><span class="string">'?s=32'</span><span>; </span></span></li><li><span><span class="func">echo</span><span> </span><span class="string">'<img  src="/static/imghwm/default1.png"  data-src="http://www.bkjia.com/uploads/allimg/151012/152R41955-1.jpg"  class="lazy"  </span alt="10个典型实用的PHP代码片段_PHP教程" ><span> . </span><span class="vars">$gravatar_link</span><span> . </span><span class="string">'" />'</span><span>; </span></span></li></ol>

七、用cURL获取RSS订阅数

<ol class="dp-c"><li class="alt"><span><span class="vars">$ch</span><span> = curl_init(); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_URL,</span><span class="string">'https://feedburner.google.com/api/awareness/1.0/GetFeedData?id=7qkrmib4r9rscbplq5qgadiiq4'</span><span>); </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_RETURNTRANSFER,1); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_CONNECTTIMEOUT,2); </span></span></li><li class="alt"><span><span class="vars">$content</span><span> = curl_exec(</span><span class="vars">$ch</span><span>); </span></span></li><li><span><span class="vars">$subscribers</span><span> = get_match(</span><span class="string">'/circulation="(.*)"/isU'</span><span>,</span><span class="vars">$content</span><span>); </span></span></li><li class="alt"><span>curl_close(<span class="vars">$ch</span><span>);  </span></span></li></ol>

八、时间差异计算

<ol class="dp-j"><li class="alt"><span><span>function ago($time) </span></span></li><li><span>{ </span></li><li class="alt"><span>   $periods = array(<span class="string">"second"</span><span>, </span><span class="string">"minute"</span><span>, </span><span class="string">"hour"</span><span>, </span><span class="string">"day"</span><span>, </span><span class="string">"week"</span><span>, </span><span class="string">"month"</span><span>, </span><span class="string">"year"</span><span>, </span><span class="string">"decade"</span><span>); </span></span></li><li><span>$lengths = array(<span class="string">"60"</span><span>,</span><span class="string">"60"</span><span>,</span><span class="string">"24"</span><span>,</span><span class="string">"7"</span><span>,</span><span class="string">"4.35"</span><span>,</span><span class="string">"12"</span><span>,</span><span class="string">"10"</span><span>); </span></span></li><li class="alt"><span> </span></li><li><span>$now = time(); </span></li><li class="alt"><span> </span></li><li><span>$difference = $now - $time; </span></li><li class="alt"><span>$tense = <span class="string">"ago"</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span><span class="keyword">for</span><span>($j = </span><span class="number">0</span><span>; $difference >= $lengths[$j] && $j < count($lengths)-</span><span class="number">1</span><span>; $j++) { </span></span></li><li><span>$difference /= $lengths[$j]; </span></li><li class="alt"><span>} </span></li><li><span> </span></li><li class="alt"><span>$difference = round($difference); </span></li><li><span> </span></li><li class="alt"><span><span class="keyword">if</span><span>($difference != </span><span class="number">1</span><span>) { </span></span></li><li><span>$periods[$j].= <span class="string">"s"</span><span>; </span></span></li><li class="alt"><span>} </span></li><li><span> </span></li><li class="alt"><span><span class="keyword">return</span><span> </span><span class="string">"$difference $periods[$j] 'ago' "</span><span>; </span></span></li><li><span>} </span></li></ol>

九、截取图片

<ol class="dp-c"><li class="alt"><span><span class="vars">$filename</span><span>= </span><span class="string">"test.jpg"</span><span>; </span></span></li><li><span>list(<span class="vars">$w</span><span>, </span><span class="vars">$h</span><span>, </span><span class="vars">$type</span><span>, </span><span class="vars">$attr</span><span>) = </span><span class="func">getimagesize</span><span>(</span><span class="vars">$filename</span><span>); </span></span></li><li class="alt"><span><span class="vars">$src_im</span><span> = imagecreatefromjpeg(</span><span class="vars">$filename</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$src_x</span><span> = </span><span class="string">'0'</span><span>; </span><span class="comment">// begin x</span><span> </span></span></li><li><span><span class="vars">$src_y</span><span> = </span><span class="string">'0'</span><span>; </span><span class="comment">// begin y</span><span> </span></span></li><li class="alt"><span><span class="vars">$src_w</span><span> = </span><span class="string">'100'</span><span>; </span><span class="comment">// width</span><span> </span></span></li><li><span><span class="vars">$src_h</span><span> = </span><span class="string">'100'</span><span>; </span><span class="comment">// height</span><span> </span></span></li><li class="alt"><span><span class="vars">$dst_x</span><span> = </span><span class="string">'0'</span><span>; </span><span class="comment">// destination x</span><span> </span></span></li><li><span><span class="vars">$dst_y</span><span> = </span><span class="string">'0'</span><span>; </span><span class="comment">// destination y</span><span> </span></span></li><li class="alt"><span> </span></li><li><span><span class="vars">$dst_im</span><span> = imagecreatetruecolor(</span><span class="vars">$src_w</span><span>, </span><span class="vars">$src_h</span><span>); </span></span></li><li class="alt"><span><span class="vars">$white</span><span> = imagecolorallocate(</span><span class="vars">$dst_im</span><span>, 255, 255, 255); </span></span></li><li><span>imagefill(<span class="vars">$dst_im</span><span>, 0, 0, </span><span class="vars">$white</span><span>); </span></span></li><li class="alt"><span> </span></li><li><span>imagecopy(<span class="vars">$dst_im</span><span>, </span><span class="vars">$src_im</span><span>, </span><span class="vars">$dst_x</span><span>, </span><span class="vars">$dst_y</span><span>, </span><span class="vars">$src_x</span><span>, </span><span class="vars">$src_y</span><span>, </span><span class="vars">$src_w</span><span>, </span><span class="vars">$src_h</span><span>); </span></span></li><li class="alt"><span> </span></li><li><span>header(<span class="string">"Content-type: image/png"</span><span>); </span></span></li><li class="alt"><span>imagepng(<span class="vars">$dst_im</span><span>); </span></span></li><li><span>imagedestroy(<span class="vars">$dst_im</span><span>); </span></span></li></ol>

十、检查网站是否宕机

<ol class="dp-c"><li class="alt"><span><span class="keyword">function</span><span> Visit(</span><span class="vars">$url</span><span>){ </span></span></li><li><span>       <span class="vars">$agent</span><span> = </span><span class="string">"Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)"</span><span>;</span><span class="vars">$ch</span><span>=curl_init(); </span></span></li><li class="alt"><span>curl_setopt (<span class="vars">$ch</span><span>, CURLOPT_URL,</span><span class="vars">$url</span><span> ); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_USERAGENT, </span><span class="vars">$agent</span><span>); </span></span></li><li class="alt"><span>curl_setopt (<span class="vars">$ch</span><span>, CURLOPT_RETURNTRANSFER, 1); </span></span></li><li><span>curl_setopt (<span class="vars">$ch</span><span>,CURLOPT_VERBOSE,false); </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>, CURLOPT_TIMEOUT, 5); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_SSL_VERIFYPEER, FALSE); </span></span></li><li class="alt"><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_SSLVERSION,3); </span></span></li><li><span>curl_setopt(<span class="vars">$ch</span><span>,CURLOPT_SSL_VERIFYHOST, FALSE); </span></span></li><li class="alt"><span><span class="vars">$page</span><span>=curl_exec(</span><span class="vars">$ch</span><span>); </span></span></li><li><span><span class="comment">//echo curl_error($ch);</span><span> </span></span></li><li class="alt"><span><span class="vars">$httpcode</span><span> = curl_getinfo(</span><span class="vars">$ch</span><span>, CURLINFO_HTTP_CODE); </span></span></li><li><span>curl_close(<span class="vars">$ch</span><span>); </span></span></li><li class="alt"><span><span class="keyword">if</span><span>(</span><span class="vars">$httpcode</span><span>>=200 && </span><span class="vars">$httpcode</span><span><300) </span><span class="keyword">return</span><span> true; </span></span></li><li><span><span class="keyword">else</span><span> </span><span class="keyword">return</span><span> false; </span></span></li><li class="alt"><span>} </span></li><li><span><span class="keyword">if</span><span> (Visit(</span><span class="string">"http://www.google.com"</span><span>)) </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">"Website OK"</span><span>.</span><span class="string">"n"</span><span>; </span></span></li><li><span><span class="keyword">else</span><span> </span></span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">"Website DOWN"</span><span>; </span></span></li></ol>

声明

本文内容由网友自发贡献，版权归原作者所有，本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容，请联系admin@php.cn

哪些常见问题会导致PHP会话失败？Apr 25, 2025 am 12:16 AM

PHPSession失效的原因包括配置错误、Cookie问题和Session过期。1.配置错误：检查并设置正确的session.save_path。2.Cookie问题：确保Cookie设置正确。3.Session过期：调整session.gc_maxlifetime值以延长会话时间。

您如何在PHP中调试与会话相关的问题？Apr 25, 2025 am 12:12 AM

在PHP中调试会话问题的方法包括：1.检查会话是否正确启动；2.验证会话ID的传递；3.检查会话数据的存储和读取；4.查看服务器配置。通过输出会话ID和数据、查看会话文件内容等方法，可以有效诊断和解决会话相关的问题。

如果session_start（）被多次调用会发生什么？Apr 25, 2025 am 12:06 AM

多次调用session_start()会导致警告信息和可能的数据覆盖。1)PHP会发出警告，提示session已启动。2)可能导致session数据意外覆盖。3)使用session_status()检查session状态，避免重复调用。

您如何在PHP中配置会话寿命？Apr 25, 2025 am 12:05 AM

在PHP中配置会话生命周期可以通过设置session.gc_maxlifetime和session.cookie_lifetime来实现。1)session.gc_maxlifetime控制服务器端会话数据的存活时间，2)session.cookie_lifetime控制客户端cookie的生命周期，设置为0时cookie在浏览器关闭时过期。

使用数据库存储会话的优点是什么？Apr 24, 2025 am 12:16 AM

使用数据库存储会话的主要优势包括持久性、可扩展性和安全性。1.持久性：即使服务器重启，会话数据也能保持不变。2.可扩展性：适用于分布式系统，确保会话数据在多服务器间同步。3.安全性：数据库提供加密存储，保护敏感信息。

您如何在PHP中实现自定义会话处理？Apr 24, 2025 am 12:16 AM

在PHP中实现自定义会话处理可以通过实现SessionHandlerInterface接口来完成。具体步骤包括：1)创建实现SessionHandlerInterface的类，如CustomSessionHandler；2)重写接口中的方法（如open,close,read,write,destroy,gc）来定义会话数据的生命周期和存储方式；3)在PHP脚本中注册自定义会话处理器并启动会话。这样可以将数据存储在MySQL、Redis等介质中，提升性能、安全性和可扩展性。

什么是会话ID？Apr 24, 2025 am 12:13 AM

SessionID是网络应用程序中用来跟踪用户会话状态的机制。1.它是一个随机生成的字符串，用于在用户与服务器之间的多次交互中保持用户的身份信息。2.服务器生成并通过cookie或URL参数发送给客户端，帮助在用户的多次请求中识别和关联这些请求。3.生成通常使用随机算法保证唯一性和不可预测性。4.在实际开发中，可以使用内存数据库如Redis来存储session数据，提升性能和安全性。