spl | 易学教程

How to use RegexIterator in PHP

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I have yet to find a good example of how to use the php RegexIterator to recursively traverse a directory. The end result would be I want to specify a directory and find all files in it with some given extensions. Say for example only html/php extensions. Furthermore, I want to filter out folders such of the type .Trash-0, .Trash-500 etc. <?php $Directory = new RecursiveDirectoryIterator("/var/www/dev/"); $It = new RecursiveIteratorIterator($Directory); $Regex = new RegexIterator($It,'/^.+\.php$/i',RecursiveRegexIterator::GET_MATCH); foreach($Regex as $v){ echo $value."<br/>"; } ?> Is what I

js 字符串函数总结(splice()、split()·····）

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1、自己比较易混淆的splice()、substring()、substr() slice方法：第一个参数指定子字符串开始位置，第二个参数表示子字符串最后一个字符后面的位置 substring方法：第一个参数指定子字符串开始位置，第二个参数表示子字符串最后一个字符后面的位置 substr方法：第一个参数指定子字符串开始位置，第二个参数表示返回的字符个数这三个方法都会返回被操作字符串的一个子字符串，都接收一或两个参数如果没有给这些方法传递第二个参数，则将字符串的长度作为结束位置。这些方法也不会修改字符串本身，只是返回一个基本类型的字符串值 2、位置方法 indexOf方法和lastIndexOf方法都是从一个字符串中搜索给定的子字符串，然后返回子字符串的位置，如果没有找到，则返回-1 indexOf方法是从字符串的开头向后搜索子字符串，lastIndexOf方法正好相反这两个方法都可以接收两个参数：要查找的子字符串和查找的位置 3、split() split方法是基于指定的字符，将字符串分割成字符串数组当指定的字符为空字符串时，将会分隔整个字符串 <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>split方法</title> </head> <body> <script type=

Codeforces 482E ELCA (LCT)

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题目链接 http://codeforces.com/contest/482/problem/E 题解 T2智商题T3大LCT题，我一个也不会= = CF的标算好像是分块？反正现在LCT都普及了就用LCT好了。首先算期望推个式子，易得答案为 $\sum_u a[u](sz[u]^2-\sum_{v\in son[u]} sz[v]^2)$ ( $sz$ 为子树大小)，令求和的那个东西等于 $f[u]$ 并且如果往一个 $u$ 里新添一个儿子 $v$ ，增添后的子树大小是 $sz[v]$ , 那么新增的答案是 $a[u]sz[v](sz[u]-sz[v])$ 然后我们要支持换父亲，动态维护这个东西后面的就是莽上一个LCT。这个只能详见代码，解释一下代码里变量的含义对于一个Splay结构体 $u$ : $ans$ : 这个点Splay的子树中所有点的 $f$ 之和。Splay的根的 $ans$ 就是要求的答案。 $sz01$ : 这个点所有虚子树的大小之和加上本身的 $1$ 。( $sz$ 是原树中子树大小) $sz02$ : 这个点本身所有虚子树的大小平方和，不包括本身。 $ans0$ : 这个点本身所有虚儿子的 $ans$ 之和。 $sz11$ : 这个点所有实儿子和虚儿子的大小之和。 $sum$

What is Autoloading; How do you use spl_autoload, __autoload and spl_autoload_register?

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I am learning advanced PHP standards and trying to implement new and useful methods. Earlier I was using __autoload just to escape including multiple files on each page, but recently I have seen a tip on __autoload manual spl_autoload_register() provides a more flexible alternative for autoloading classes. For this reason, using __autoload() is discouraged and may be deprecated or removed in the future. but I really can't figure out how to implement spl_autoload and spl_autoload_register Brownbay spl_autoload_register() allows you to register multiple functions (or static methods from your own

iMX6Q Sabresd Board SPL Mode

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uboot 2014以后的版本已经加入了支持快速启动的spl模式，本文用iMX6Q-SDP开发板做个简单讲解在官方的yocot中下载fsl-L4.9.11_1.0.0-ga版本代码并编译，提取出uboot、kernel和rootfs做为SPL模式的示范看一下uboot官方对SPL和过去对比的描述如下是denx对spl的描述如下是SPL模式的简易时序图如下针对iMX6Q Sabresd SD开发板打开SPL模式 uboot部分开发板对应的配置文件为mx6qsabresd_defconfig 打开SPL模式需要在配置文件加入一个宏CONFIG_SPL=y 此时的defconfig配置文件已经打开SPL模式了，能够完成boot_rom --> SPL --> uboot --> kernel 的过程了但此时还没达到快速启动的目的，需要跳过uboot直达kernel才行：boot_rom --> SPL --> kernel 为此查看uboot/README的SPL framework部分 CONFIG_SPL Enable building of SPL globally. 此项我们在defconfig中已经打开 CONFIG_SPL_OS_BOOT Enable booting directly to an OS from SPL. See also: doc

How can I retrieve the full directory tree using SPL?

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问题 How can I retrieve the full directory tree using SPL , possibly using RecursiveDirectoryIterator and RecursiveIteratorIterator ? 回答1: By default, the RecursiveIteratorIterator will use LEAVES_ONLY for the second argument to __construct. This means it will return files only. If you want to include files and directories (at least that's what I'd consider a full directory tree), you'd have to do: $iterator = new RecursiveIteratorIterator( new RecursiveDirectoryIterator($path),

How to use RegexIterator in PHP

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问题 I have yet to find a good example of how to use the php RegexIterator to recursively traverse a directory. The end result would be I want to specify a directory and find all files in it with some given extensions. Say for example only html/php extensions. Furthermore, I want to filter out folders such of the type .Trash-0, .Trash-500 etc. <?php $Directory = new RecursiveDirectoryIterator(\"/var/www/dev/\"); $It = new RecursiveIteratorIterator($Directory); $Regex = new RegexIterator($It,\'/^.+

How does RecursiveIteratorIterator work in PHP?

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问题 How does RecursiveIteratorIterator work? The PHP manual has nothing much documented or explained. What is the difference between IteratorIterator and RecursiveIteratorIterator ? 回答1: RecursiveIteratorIterator is a concrete Iterator implementing tree traversal. It enables a programmer to traverse a container object that implements the RecursiveIterator interface, see Iterator in Wikipedia for the general principles, types, semantics and patterns of iterators. In difference to IteratorIterator

What is Autoloading; How do you use spl_autoload, __autoload and spl_autoload_register?

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问题 I am learning advanced PHP standards and trying to implement new and useful methods. Earlier I was using __autoload just to escape including multiple files on each page, but recently I have seen a tip on __autoload manual spl_autoload_register() provides a more flexible alternative for autoloading classes. For this reason, using __autoload() is discouraged and may be deprecated or removed in the future. but I really can\'t figure out how to implement spl_autoload and spl_autoload_register 回答1

How does RecursiveIteratorIterator work in PHP?

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How does RecursiveIteratorIterator work? The PHP manual has nothing much documented or explained. What is the difference between IteratorIterator and RecursiveIteratorIterator ? RecursiveIteratorIterator is a concrete Iterator implementing tree traversal . It enables a programmer to traverse a container object that implements the RecursiveIterator interface, see Iterator in Wikipedia for the general principles, types, semantics and patterns of iterators. In difference to IteratorIterator which is a concrete Iterator implementing object traversal in linear order (and by default accepting any

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