permissions are numeric:
Basic Permissions r=4 w=2 x=1
Additional permissions suid=4 sgid=2 Stiky bit=1
Set permissions by using numeric form
Space occupied by the statistics file: Du
du [Options] ... [Directory or file]
-S: Counts the total amount of space occupied by each parameter only
-H: Provides easy-to-read capacity units (K, M, etc.)
[Email protected] ~]# du-sh/root//etc//boot/
4.0M/root/
35M/etc/
132M/boot/
Date: View/adjust system date Time
-date +%f #年月日
-date +%r #时间
-date + "%y-%m-%d%h:%m:%s" #年月日, seconds and minutes
-date-s "Yyyy-mm-dd HH:MM:SS" #修改日期时间
Vim text editing
Cursor Jump
Home key or ^, number 0 jump to beginning of line
End key or jump to end of line
PgUp key, PgDn key to page up and down
1G or GG jumps to the first line of the entire file
G jump to the end of the entire file line
Copy and paste
yy, Nyy copy one row, n rows at the cursor
P
/ROOT/.VIMRC #此文件默认没有, but can be modified in vim configuration
Vim/root/.vimrc
Create a soft connection (shortcut): ln-s
[Email protected] ~]# ln-s/etc/sysconfig/network-scripts/ifcfg-eth0/opt/eth0
[Email protected] ~]# ls-l/opt/eth0
lrwxrwxrwx. 1 root root 41 November 14:11/opt/eth0-/etc/sysconfig/network-scripts/ifcfg-eth0
System Environment variables
PATH:
./Currently running the program
-mtime + or-change the number of days (only past time)
0.0.0.0:22
Indicates that all IP addresses (network cards) of this machine are open port 22nd
linux-extension Application: Vim editing skills, distribution network yum source, source code compilation and installation