Common Red Hat commands

1. Configuration:
# Setup
2. Protection Wall:
#/Sbin/service iptables start stop restart
3. FTP:
# Yum install vsftpd;
# Yum remove vsftpd;
#/Sbin/service vsftpd start stop restart;
# Vi/etc/vsftpd. conf
4. Re-obtain the IP Address:
# Dhclient-R
# Dhclient
5. user operations
#/Usr/sbin/useradd yourname
#/Usr/bin/passwd yournam
6. Background running:
$./Test. Sh &
[1] 17208
$ Jobs-l
[1] + 17208 running./test. Sh &
$./Test. Sh
[1] + stopped./test. Sh
$ BG % 1
[1] +./test. Sh &
$ Jobs-l
[1] + 22794 running./test. Sh &
$ Echo $
21734
$ Nohup./test. Sh &
[1] 29016
$ PS-Ef | grep Test
515 29710 21734 0 00:00:00 pts/12/bin/sh./test. Sh
515 29713 21734 0 00:00:00 pts/12 grep Test
$ Setsid./test. Sh &
[1] 409
$ PS-Ef | grep Test
515 410 1 0? 00:00:00/bin/sh./test. Sh
515 413 21734 0 00:00:00 pts/12 grep Test
$./Test. Sh &
[1] 2539
$ Jobs-l
[1] + 2539 running./test. Sh &
$ Disown-H % 1
$ PS-Ef | grep Test
515 410 1 0? 00:00:00/bin/sh./test. Sh
515 2542 21734 0 00:00:00 pts/12 grep Test
$ (./Test. Sh &)
$ PS-Ef | grep Test
515 410 1 0? 00:00:00/bin/sh./test. Sh
515 12483 21734 0 00:00:00 pts/12 grep Test
$ Screen-DMs screen_test
$ Screen-list
There is a screen on:
27963. screen_test (detached)
1 socket in/tmp/uscreens/S-Jiangfeng.
$ Screen-r screen_test
7. nohup Program Output to nohup. Out by default. You can set it by yourself: nohup test. Sh> test. log &

8. Date
View System Time:
# Date
Set system time
# Date -- set "07/07/06" (month/day/year hour: minute: second)
 
9. hwclock/clock
View hardware time
# Hwclock -- show or # clock -- show
Set hardware time
# Hwclock -- set -- date = "07/07/06" (month/day/year hour: minute: second) or # clock -- set -- date = "07/07/06" (month/day/year hour: minute: second)

10. Change the file owner and group:
Chown Nile filename
Chown-r Nile dir
Chgrp Nile filename
11. View Hard Disk Partitions
DF-lH
Fdisk-l
12. View CPU
CAT/proc/cpuinfo
13. view memory
CAT/proc/meminfo
14. Logs
# Cd/var/log
# Less secure
Or
# Less messages
Recent logon logs:
# Last
15. view the directory size
# Du-SH
View and sort files under root
# Du-SH/* | sort-n
Or
# Du-Sm/* | sort-n

16.7z supports Chinese Compression

Supports 7z, zip, zip64, cab, rar, ARJ, Gzip, Bzip2, tar, cpio, rpm, ISO, and Deb compressed file formats.

Install: sudo apt-Get install p7zip p7zip-full p7zip-rar

# 7z A yajiu.7z yajiu.jpg yajiu.png
This command compresses yajiu.jpgand yajiu.png into a 7z package.
# 7z A yajiu.7z *. jpg
This command compresses all .jpg files into a 7z package.
# 7z A yajiu.7z yajiu
This command compresses the folder yajiu into a 7z package
# 7z e yajiu.7z
This command is to decompress all the files in yajiu.7z and E is to the current path.
# 7z x yajiu.7z
This command is to decompress all the files in yajiu.7z, and X is to the directory named after the compressed package.

17. Find command

Find Command Format: Find [<path>] [matching condition]
(1) Search for a file named passwd from the root directory.
Root @ Ubuntu :~ # Find/-name passwd
(2) Find the files that have been accessed in the/usr directory for the first 10 days (only 10th days ).
Root @ Ubuntu :~ # Find/usr-atime 10
3) Search for the files that were accessed 10 days ago in the/usr directory.
Root @ Ubuntu :~ # Find/usr-atime + 10
(4) Find the files that have been accessed 10 days before under the/usr directory.
Root @ Ubuntu :~ # Find/usr-atime-10
(5) list all files with the "Doc" extension in the current directory.
Root @ Ubuntu :~ # Find-name "*. Doc"
6) Find the files in the/etc/home directory with a size smaller than 4 K.
Root @ Ubuntu :~ # Find/etc/home-size-4 K

The size units of files accepted by the find command include bytes (C), blocks (B, 512 bytes), and K (K, 1024 bytes.

18. User Management

VI/etc/passwd

VI/etc/shadow

VI/etc/group

Uersadd Username

Userdel Username

Passwd Username

Locked account passwd-l Username

Unlock passwd-u Username

Usermod Username

Groupadd groupname

Groupmod groupname

Groupdel groupname