Rhcsa second day operation

1. Use timedatectl View time status List all known time zones Modify the time zone to one of the listed time zones

[root@localhost ~]# timedatectl 
               Local time: Mon 2022-04-11 21:39:52 CST
           Universal time: Mon 2022-04-11 13:39:52 UTC
                 RTC time: Sun 2022-04-03 07:13:58
                Time zone: Asia/Shanghai (CST, +0800)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no
​
[root@localhost ~]# timedatectl list-timezones 
#  This command lists all known time zones 
​
[root@localhost ~]# timedatectl set-timezone "America/New_York"
[root@localhost ~]# timedatectl status 
\               Local time: Mon 2022-04-11 09:46:03 EDT
           Universal time: Mon 2022-04-11 13:46:03 UTC
                 RTC time: Sun 2022-04-03 07:20:09
                Time zone: America/New_York (EDT, -0400)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no
​

2. Use wget Command in Pear video official website - Make the best information short video -Pear Video Download any video from this website

[root@localhost ~]# wget https://video.pearvideo.com/mp4/adshort/20220411/cont-1758285-15860104_adpkg-ad_hd.mp4
--2022-04-12 18:55:11--  https://video.pearvideo.com/mp4/adshort/20220411/cont-1758285-15860104_adpkg-ad_hd.mp4
Resolving video.pearvideo.com (video.pearvideo.com)... 219.144.100.225, 219.144.100.224, 219.144.100.219, ...
Connecting to video.pearvideo.com (video.pearvideo.com)|219.144.100.225|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 18205895 (17M) [video/mp4]
Saving to: ‘cont-1758285-15860104_adpkg-ad_hd.mp4’
​
cont-1758285-15860104_adpkg-ad_hd.mp4              100%[=============================================================================================================>]  17.36M  1.09MB/s    in 15s     
​
2022-04-12 18:55:26 (1.19 MB/s) - ‘cont-1758285-15860104_adpkg-ad_hd.mp4’ saved [18205895/18205895]
​

3.Linux File types and symbol representations in

Linux There are common files in the file type 、 Directory file 、 Link to the file 、 Block device file 、 Character device file 、 Pipeline files 、 Socket file .

d：directory, Represents a catalog file 
-： Ordinary documents 
l：link, Represents a linked file 
b：block, Represents a block device file 
c：character, Represents a character device file 
p：pipe： Represents a pipeline file 
s：socket, Represents a socket file 

4. Create directory test, And use a command in test Create test1/test2/test3

[root@localhost ~]# mkdir test
[root@localhost ~]# cd test
[root@localhost test]# mkdir -p test1/test2/test3

a. Output test3 Full path to

[root@localhost test3]# pwd
/root/test/test1/test2/test3

b. Created above test3 Create under directory file1 And the modification time of the document is 20220319

[root@localhost test3]# touch -d 20220319 file1
​

c. see file1 Details of

[root@localhost test3]# stat file1
  File: file1
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 1135736     Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Context: unconfined_u:object_r:admin_home_t:s0
Access: 2022-03-19 00:00:00.000000000 +0800
Modify: 2022-03-19 00:00:00.000000000 +0800
Change: 2022-04-11 21:56:10.971104264 +0800
 Birth: 2022-04-11 21:50:57.521085749 +0800