Life in the first blog, do not know the future will not watch (Wulian)
Linux mainstream operating system: CentOS, Ubuntu, Android.
All of the Linux operating system is a Linux kernel + GNU Tools of. Generally we use the Linux kernel version are older, because the older version is more stable. Linux kernel version consists of three parts (major version, minor version number, the version number at the end). GUN then commonly used tools bash, vim and so on.
The current market popular Linux distributions there are three major schools: slackware, debian, redhat. Each release of Enterprise version is as follows:
Slackware-SUSE Linux Enterprise Server 12 SP2, released by Novell;
Debian Linux Debian-9, issued by the maintenance of Debian community;
RedHat-RedHat Enterprise Linux 7.3, RedHat issued by the company; 
commonly used release there are Ubuntu, CentOS, Gentoo, etc.
Ubuntu is suitable for development use; CentOS relatively stable, suitable for operation and maintenance use; Gentoo is very simple, after the system Bahrain, in addition to the basic system software, other applications requires its own one by one to install, more suitable for experienced users. About LFS-Linux From Scrtch, it's like a manual, step by step teach you how to build one of their own Linux system, but the job requires a certain basis. Be learning to medium term, I will try to operate it. If the build is successful, we can deepen understanding of Linux.
接下来再分享几个Linux的小命令。
打印显示当前时间，date命令可以查看当前的系统时间
Can also modify the system time with the date (time hardware will not change), the format: date + MMDDHHmmYYYY.ss, 21:10:08 to 2018/12/09, for example,
However, date modified only time systems, hardware time will not change, clock can view the hardware of the time,
Want to put the system back to the time of hardware time, with clock -s, as follows,
Want to set a time virtual machine automatically shut down, shutdown time can be directly coupled, while here and then prompts the user to set the shutdown, with between command; separated as follows:
Use history to view the history of executed commands, each command used has a corresponding number, use! + Serial number can execute this command again
至于历史命令能存多少条呢，一般来说都是默认1000条，可以用echo $HISTSIZE查看，可以直接用HISTSIZE=3000来把容量改为3000条，当超过3000条，则会自动顺延记录，原来的第一条就没啦Each command has its own instructions to help guide us to use, help CMMAND or man bash can view the help internal command to view the external command method is more and more. 1.CMMAND - help or CMMAND-h. 2. Manual (manual), man CMMAND. 3. Information page, info CMMAND. 4. The program itself help documentation, README, INSTALL, ChangeLog. 5. Program official document, the official site: Documentation. 6. The release of official documents. 7.Google