Brother Bird's Linux private dish--the eighth chapter

Refer to the bird Brother's Linux private food content, I just simple record more important knowledge points, so the layout is not much attention, if the writing too serious small white also can not see in it.

Watch the video! This article only serves as a memo

　　

Video link: http://www.tudou.com/programs/view/zh6ckMB6kNg

　　

Graphical interface x conversion of Windows and text mode CTRL+ALT+F1-6/7

Date View Time

Cal look calendar cal 7 cal after two parameters, month and year can also Cal 2017 see year-round

BC Calculator Support +-*/% and index default is an integer, plus a scale=3 can determine 3 digits after the decimal point quit

　　

The TAB key can be complete:

CTRL + C key combination abort current program, find/-type [b ...] press this and try the combination.

Ctrl+d Combo key equivalent to exit

Man and Info Help

Man: For example, the numbers behind my man date are these meanings.

　　

Introduction to the man page

　　

Shortcut keys inside the man page

　　

Info does not introduce

Do not unplug the power off, it is best to use shutdown, restart the use of reboot

Data synchronously written to disk: Sync

In a Linux system, in order to speed up the reading speed of the data, some data will not be written directly to the hard disk in a preset situation.
Instead, the memory is present, so that if a data is rewritten by you repeatedly, because he has not yet been written to the hard disk,
Can be read directly from memory, in the speed must be very fast on quite a lot!
However, this is also a bit of a problem, that is, in case you reboot, or shutdown, or an abnormal power loss of the situation
The data has not been written to the hard drive, wow! So it will cause the data update is not normal! What do we do then? This time
You need the sync command to write the data! Enter sync directly under the text interface, then the memory is not
The new data will be written to the hard drive! So, this command is important before the system shuts down or reboots. It's best to do it several times!
(Note: This command is also only root can be executed!) )
Although the current shutdown/reboot/halt and so on are already in the shutdown before the sync this tool call, however, do more
A few times is always more reassuring ~ hehe ~

　　

Brother Bird's Linux private dish--the eighth chapter