linux boot process A Linux system goes through several stages when booting. the firmware stage the computer runs code in BIOS or UEFI during power on self test or post. Older computers hav...

file access control [toc] Permissions 更改文件属性 The Unix-like operating systems, differ from other computing systems in that they are not only multitasking but also multi-user. more than one user...

[toc] Daemons also known as background processes a Linux or UNIX program that runs in the background. Almost all daemons have names that end with the letter “d”. For example, ...

CentOS [toc] check Version $ cat /etc/os-release $ cat /etc/centos-release CentOS Linux release 8.1.1911 (Core) Setup kernel check the exact version of kernel uname -a. check the kerne...

linux vi/vim [toc] Linux vi/vim 所有的 Unix Like 系统都会内建 vi 文书编辑器，其他的文书编辑器则不一定会存在。 vi 是老式的字处理器，不过功能已经很齐全了，但是还是有可以进步的地方。 vim 则可以说是程序开发者的一项很好用的工具。具有程序编辑的能力，可以主动的以字体颜色辨别语法的正确性，方便程序设计。 vim 键盘图： ...

sed (“stream editor”) parses and transforms text, using a simple, compact programming language. most notably with the substitution command. Popular alternative tools for plaintext string ma...

Linux - Sysfile [toc] /etc/passwd $ sudo cat /etc/passwd ---------------------------------------------- Username, password, uid, gid, comment, home directory, default shell -------------------...

PAM [toc] PAM = Pluggable Authentication Modules PAM Services 4 types of PAM services: Authentication service modules. Account management modules. Session management modules. Password ...

Linux Socket [toc] 1. 网络中进程之间通信 我们深谙信息交流的价值，那网络中进程之间如何通信，如我们每天打开浏览器浏览网页时，浏览器的进程怎么与web服务器通信的？当你用QQ聊天时，QQ进程怎么与服务器或你好友所在的QQ进程通信？这些都得靠socket？那什么是socket？socket的类型有哪些？还有socket的基本函数 本地的进程间通信（IPC）有很多...

cron [toc] basic Cron command for periodic processing. Periodic processing is necessary to make sure systems are functioning correctly. Cron is our scheduler. to execute anything, arbitra...

NFS [toc] Assignment under: LFCE: Advanced Network and System Administration / Configuring and Managing NFS - LFCEbyPluralsight NFS file permission UID and GID overlap: configuration file s...

NFS [toc] Assignment under: LFCE: Advanced Network and System Administration / Configuring and Managing NFS - LFCEbyPluralsight NFS file permission UID and GID overlap: configuration file s...

Install Samba in CentOS8 [toc] Assignment under: LFCE: Advanced Network and System Administration / Configuring and Managing Samba - LFCEbyPluralsight .

Install OpenLDAP Directory in CentOS 8 [toc] Assignment under: CentOS Enterprise Linux 7 User and Group Management / Implementing OpenLDAP - LFCEbyPluralsight install OpenLDAP server0: =====...

Install NTP in CentOS8 [toc] Assignment under: LFCE: Advanced Network and System Administration / Configuring and Managing NFS - LFCEbyPluralsight NTP an accurate system time on a Linux server...