linux-extension Application: Vim editing skills, distribution network yum source, source code compilation and installation

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

Soft connections and hard connections

difference : Soft Connection -if the original file or directory is deleted, the connection file will expire

Soft connections can be stored in different partitions/file systems

Hard Connect -The connection file is still available if the original file is deleted

Hard connections with original files must be in the same partition/file system

Hard Connect does not support creating directories

Create soft connection (shortcut): ln-s original File/directory soft connection file

[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

Create a hard connection : ln Raw file hard connect file

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