auto

NFS服务器搭建与autofs自动挂载

蓝咒 提交于 2019-12-04 16:41:34
nfs搭建 NFS = Network File System 所需安装环境 RPC RPC = Remote Procedure Call #共享主机需要 RPC rpcbind NFS nfs-server #访问主机需要 RPC rpcbind 建立方法 #编辑配置文件 vi /etc/exports 设置固定端口 修改 /etc/sysconfig/nfs 文件 MOUNTD_PORT="4002" STATD_PORT="4003" LOCKD_TCPPORT="4004" LOCKD_UDPPORT="4004" 远程挂载 mount.nfs 192.168.1.204:/public /public 开机自动挂载公共目录 vi /etc /fstab autofs配置 安装autofs --->yum install autofs 在下面的目录下,添加主映射文件 /etc/auto.master.d/share.autofs #一定要加上.autofs后缀,前面的share可以随意改 /share /etc/auto.demo #前面/share为挂载点的目录,服务启动会自动生成,后面的为映射文件,名称随意 创建映射文件/etc/auto.demo work -rw,sync <host>:/<dirname> #参数和mount相同,work为挂载点,在

autofs自动挂载

放肆的年华 提交于 2019-12-04 15:43:05
NFS,是Network File System的简写,即网络文件系统。网络文件系统是FreeBSD支持的文件系统中的一种,也被称为NFS. NFS允许一个系统在网络上与他人共享目录和文件。通过使用NFS,用户和程序可以像访问本地文件一样访问远端系统上的文件。 模式: C/S 模式 端口:RHEL6是以NFSv4作为默认版本,NFSv4使用TCP协议(端口号是2049)和NFS服务器建立连接 autofs 说明 自动挂载器是一个监视目录的守护进程,并在目标子目录被引用时,自动执行预定义的挂载 自动挂载器由autofs服务脚本管理 自动挂载器由auto.master配置文件进行配置,该文件引用了一个按惯例称作/etc/auto.misc 本文介绍如何通过autofs服务,将本地镜像 /dev/cdrom 自动挂载到文件系统。 安装autofs [root@localhost home]# yum install -y autofs 配置autofs [root@localhost home]# rpm -qc autofs 编写配置文件 /etc/auto.master vim /etc/auto.maser ..... # /media是指挂载点放在这个目录下; # /etc/iso.misc是子配置文件,需要我们来编写挂载信息 /media /etc/iso.misc

`static constexpr auto` data-member initialized with unnamed enum

旧巷老猫 提交于 2019-12-04 15:22:39
问题 I was working on a C++11 project solely using clang++-3.4 , and decided to compile using g++-4.8.2 in case there were any discrepancies in the errors produced. It turned out that g++ rejects some code that clang++ accepts. I have reduced the problem to the MWE given below. enum { a }; template <class T> struct foo { static constexpr auto value = a; }; int main() { static constexpr auto r = foo<int>::value; } foo.cpp:5:23: error: ‘ const<anonymous enum> foo<int>::value ’, declared using

how to SFINAE for enabling member function returning `auto`

放肆的年华 提交于 2019-12-04 13:10:26
In template meta programming, one can use SFINAE on the return type to choose a certain template member function, i.e. template<int N> struct A { int sum() const noexcept { return _sum<N-1>(); } private: int _data[N]; template<int I> typename std::enable_if< I,int>::type _sum() const noexcept { return _sum<I-1>() + _data[I]; } template<int I> typename std::enable_if<!I,int>::type _sum() const noexcept { return _data[I]; } }; However, this won't work if the function in question ( _sum() in above example) has auto-detected return type, such as _func() in this example template<int N> class A { /*

Can the use of C++11's 'auto' deteriorate performance or even break the code?

孤者浪人 提交于 2019-12-04 12:39:08
This question is the opposite of an existing question " Can the use of C++11's 'auto' improve performance? " One of the answers to that question indicated that usage of auto can have not only positive but also negative effects. I believe we need a separate question, with answers focusing on that side of auto . Leon With auto there is no conversion at the variable declaration+initialization line. But if such conversion must happen anyway, it better happen once during initialization than multiple times later. struct X { ... }; struct Y { operator X() const; ... }; Y foo(); // maybe, originally

我厌倦了 Redux,那就造个轮子 Rectx:第三集

核能气质少年 提交于 2019-12-04 09:33:42
仓库:215566435/rectx 前言 麻烦快去我的仓库里面喷: 老子学不动了,求不要更新。 呵呵,你没想到吧,这玩意儿竟然有第三集!我靠,我自己都没想到,让我们悄悄的回顾一下前两集 完全没想到,竟然会有第二集! 我厌倦了 Redux,那就造个轮子 Rectx 第二集: immutable 痛点分析 第一集在这里:我厌倦了Redux,那就造个轮子:Rectx 算了,我都懒得写了,自己看吧,当然不看也无所谓,正式开始。 新的 Rectx 有什么不同? a light-weight state manager with mutable api. 有人就说了,你说 light-weight 就 来喂 ??那是肯定是,这个库大小只有几 k 。其次,新版的 Rectx 并不依赖 React.context ,因此可以在任何 react 版本中使用。 当然,短短60行核心代码,我写了不少的测试,覆盖率也来到了98%。 那,为什么又更新了? Redux 和 Mobx 都非常的棒,但对于大部分项目都只是 CRUD 的项目来说,这些个玩意儿都略显太重了。 而且对于 react 的 immutable 哲学而言,实在是模版代码相当的多,对新手、高手、熟练工都不是很友好:新手觉得复杂,高手觉得烦躁,熟练工觉得不够快。 再加上, react 函数式编程以及 DOM-diff 依赖的是 html tag

GCC's decltype(auto) doesn't conform to the standard?

一个人想着一个人 提交于 2019-12-04 04:24:58
I tried compiling this C++ code under GCC 8.2 with different options and it always succeeds, produces no warnings and outputs true : int && a = 123; decltype(auto) b = a; std::cout << std::boolalpha << std::is_same<decltype(b), int&>::value; Meanwhile, the same code will not compile in Clang, and if my understanding of the standard is correct, that's the standard-conforming behavior. cppreference on decltype : If the argument is an unparenthesized id-expression or an unparenthesized class member access expression, then decltype yields the type of the entity named by this expression.

What does the auto c++ keyword do? [duplicate]

不打扰是莪最后的温柔 提交于 2019-12-04 04:00:02
问题 This question already has answers here : What is the point of the 'auto' keyword? (7 answers) C++ auto keyword. Why is it magic? (5 answers) Closed 5 years ago . I recently came accross the keyword auto in c++. In the code: auto maxIterator = std::max_element(&spec[0], &spec[sampleSize]); float maxVol = *maxIterator; // Normalize if (maxVol != 0) std::transform(&spec[0], &spec[sampleSize], &spec[0], [maxVol] (float dB) -> float { return dB / maxVol; }); This is to do with running a frequency

Is there a way to disable auto declaration for non regular types?

谁说胖子不能爱 提交于 2019-12-04 00:42:17
问题 UPDATE: There is a proposal to change the meaning of auto in certain situations. Implicit Evaluation of “auto” Variables and Arguments by Joel Falcou and others. The implicit evaluation shall: Enable class implementers to indicate that objects of this class are evaluated in an auto statement; Enable them to determine the type of the evaluated object; ... C++11's auto keyword is great. However in my opinion if a type is Not Regular (see for example, What is a "Regular Type" in the context of

C++14 using auto keyword in a method's definition

。_饼干妹妹 提交于 2019-12-04 00:31:38
I have several std::unordered_maps . They all have an std::string as their key and their data differs. I want to make a csv string from a given map's keys because that data needs to be sent over the wire to a connected client. At the moment I have a method for each individual map. I wanted to make this generic and I came up with the following : std::string myClass::getCollection(auto& myMap) { std::vector <std::string> tmpVec; for ( auto& elem : myMap) { tmpVec.push_back(elem.first); } std::stringstream ss; for ( auto& elem : tmpVec ) { ss << elem <<','; } std::string result=ss.str(); result