博文

目前显示的是标签为“Linux”的博文

PHP8 —— New String Helpers

新增了三个字符串函数,str_starts_with, str_ends_with, str_contains, PHP 的函数这么方便,很难想象竟然一直没有这几个。 str_starts_with 判断字符串是否以另一个字符串开头,在PHP7以及之前 $id = 'inv_abcdefgh'; $result = strpos($id, 'inv_') === 0; var_dump($result); // true PHP8 中可以直接这么写 $result = str_starts_with($id, 'inv_'); str_ends_with 判断字符串是否以另外一个字符串结尾,在 PHP7 及之前,比较麻烦,通常是这么写 $id = 'abcd_inv'; $result = strpos(strrev($id), strrev('_inv')) === 0; 或者 $result = substr($id, -1 * strlen('_inv')) === '_inv'; 或者上正则吧 $result = preg_match('/_inv$/', $id) === 1; 看起来都是比较麻烦的。PHP8 里面可以简化成下面这样了 $id = 'abcd_inv'; $result = str_ends_with($id, '_ind'); str_contains 字符串包含,PHP8 之前一般就是 strpos 来实现了 $url = 'https://example?for=bar'; $result = strpos($url, '?') !== FALSE; PHP8 就直接一点 $result = str_contains($url, '?');

Difference between buffer and cache

free Buffer and Cache are the indicators we get with free. buffers Memory used by kernel buffers (Buffers in/proc/meminfo) cache Memory used by the page cache and slabs (Cached and SReclaimable in/proc/meminfo) buff/cache Sum of buffers and cache From the free manual, you can see the description of buffer and cache.   Memory used by kernel buffers, corresponding to the Buffers value in/proc/meminfo. Cache is the kernel page cache and the memory used by Slab, which corresponds to the sum of Cached and SReclaimable in/proc/meminfo. The description here tells us that these values are from/proc/meminfo, but the meaning of more specific Buffers, Cached, and SReclaimable is still not clear. To figure out what they are, I guess your first reaction is to go to Baidu or Google. Although most of the time, a web search will give an answer. However, not to mention the time and effort spent on filtering information, it is difficult for you to guarantee the accuracy of this answ...