对于日常工作中整理出来的某些功能做个简单梳理:

1. 短链生成算法

function code62($x) {$show = '';while($x > 0) {$s = $x % 62;if ($s > 35) {$s = chr($s+61);} elseif ($s > 9 && $s <=35) {$s = chr($s + 55);}$show .= $s;$x = floor($x/62);}return $show;
}function shorturl($url) {$url = crc32($url);$result = sprintf("%u", $url);//return $url;//return $result;return code62($result);
}br( shorturl("http://pai.game.weibo.com/love/") );
br( shorturl("http://www.oschina.net/code/snippet_878945_22499") );

2. 比较字符串差异:

levenshtein()你有没有经历过需要知道两个单词有多大的不同的时候，这个函数就是来帮你解决这个问题的。它能比较出两个字符串的不同程度。用法：<?php
$str1 = "carrot";
$str2 = "carrrott";
echo levenshtein($str1, $str2); //Outputs 2?>

3. 删除文件空格

php_strip_whitespace这个函数也跟前面的show_source()函数相似，但它会删除文件里的注释和空格符。用法：<?php
echo php_strip_whitespace("php_script.php");
?>

4. 内存信息查看

memory_get_usage(),memory_get_peak_usage(),getrusage()这些函数用来获取内存和CPU使用情况，memory_get_usage()函数返回内存使用量，memory_get_peak_usage()函数返回内存使用峰值，getrusage()返回CUP使用情况，在调试PHP代码性能时，这些函数会给你提供一些有用信息。但有一点请注意，在这些函数中Window上无效。用法：<?php
echo "Initial: ".memory_get_usage()." bytes \n";
echo "Peak: ".memory_get_peak_usage()." bytes \n";
$data = getrusage();
echo "User time: ".($data['ru_utime.tv_sec'] +$data['ru_utime.tv_usec'] / 1000000);
echo "System time: ".($data['ru_stime.tv_sec'] +$data['ru_stime.tv_usec'] / 1000000);?>

5. 字符串压缩

gzcompress(), gzuncompress()这两个函数用来压缩和解压字符串数据。它们的压缩率能达到50% 左右。另外的函数 gzencode() 和 gzdecode() 也能达到类似结果，但使用了不同的压缩算法。用法：<?php
$string =
"Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Nunc ut elit id mi ultricies
adipiscing. Nulla facilisi. Praesent pulvinar,
sapien vel feugiat vestibulum, nulla dui pretium orci,
non ultricies elit lacus quis ante. Lorem ipsum dolor
sit amet, consectetur adipiscing elit. Aliquam
pretium ullamcorper urna quis iaculis. Etiam ac massa
sed turpis tempor luctus. Curabitur sed nibh eu elit
mollis congue. Praesent ipsum diam, consectetur vitae
ornare a, aliquam a nunc. In id magna pellentesque
tellus posuere adipiscing. Sed non mi metus, at lacinia
augue. Sed magna nisi, ornare in mollis in, mollis
sed nunc. Etiam at justo in leo congue mollis.
Nullam in neque eget metus hendrerit scelerisque
eu non enim. Ut malesuada lacus eu nulla bibendum
id euismod urna sodales. ";$compressed = gzcompress($string);
$original = gzuncompress($compressed);?>