Linux 常用的查询命令汇总

[root@localhost ~]# cat /etc/redhat-release   查看CentOS版本
CentOS Linux release 7.9.2009 (Core)

[root@localhost ~]# cat /proc/version   查看内核版本
Linux version 3.10.0-1160.24.1.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) ) #1 SMP Thu Apr 8 19:51:47 UTC 2021

[root@localhost ~]# uname -a
Linux localhost.localdomain 3.10.0-1160.24.1.el7.x86_64 #1 SMP Thu Apr 8 19:51:47 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[root@localhost ~]# getconf LONG_BIT   查看系统位数
64

[root@localhost ~]# lsb_release -a  列出所有版本信息
LSB Version:	:core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID:	CentOS
Description:	CentOS Linux release 7.9.2009 (Core)
Release:	7.9.2009
Codename:	Core
##注意如果没有这个命令，需要安装yum -y install redhat-lsb

[root@localhost ~]# cat /proc/cpuinfo | grep name | cut -f2 -d: | uniq -c
      4  Intel(R) Xeon(R) CPU           E5606  @ 2.13GHz
[root@localhost ~]# 

[root@localhost ~]# df -h
文件系统                 容量  已用  可用 已用% 挂载点
devtmpfs                 7.8G     0  7.8G    0% /dev
tmpfs                    7.8G     0  7.8G    0% /dev/shm
tmpfs                    7.8G  9.2M  7.8G    1% /run
tmpfs                    7.8G     0  7.8G    0% /sys/fs/cgroup
/dev/mapper/centos-root   50G  5.4G   45G   11% /
/dev/sda1               1014M  186M  829M   19% /boot
/dev/mapper/centos-home  220G   33M  220G    1% /home
overlay                   50G  5.4G   45G   11% /var/lib/docker/overlay2/012161edd1ee2721c9d3dabc3ac4df1591e6d23444973a9c52083f4aa7399df6/merged
tmpfs                    1.6G     0  1.6G    0% /run/user/0
[root@localhost ~]# 

[root@localhost ~]# env
XDG_SESSION_ID=3
HOSTNAME=localhost.localdomain
TERM=xterm
SHELL=/bin/bash
HISTSIZE=1000
SSH_CLIENT=10.5.1.200 10730 22
SSH_TTY=/dev/pts/0
USER=root
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=01;05;37;41:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=01;36:*.au=01;36:*.flac=01;36:*.mid=01;36:*.midi=01;36:*.mka=01;36:*.mp3=01;36:*.mpc=01;36:*.ogg=01;36:*.ra=01;36:*.wav=01;36:*.axa=01;36:*.oga=01;36:*.spx=01;36:*.xspf=01;36:
MAIL=/var/spool/mail/root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin
PWD=/root
LANG=zh_CN.UTF-8
HISTCONTROL=ignoredups
SHLVL=1
HOME=/root
LOGNAME=root
SSH_CONNECTION=10.5.1.200 10730 10.5.6.248 22
LESSOPEN=||/usr/bin/lesspipe.sh %s
XDG_RUNTIME_DIR=/run/user/0
_=/usr/bin/env

[root@localhost ~]# uptime
 12:00:46 up  1:33,  1 user,  load average: 0.00, 0.01, 0.05

1.当前时间：12:00:46
2.系统运行了多少时间,1:33（1小时33分)
3.多少个用户,1 users
4.平均负载：0.00, 0.01, 0.05，最近1分钟、5分钟、15分钟系统的负载

[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:          15873         715       14376           9         781       14875
Swap:          8063           0        8063

[root@localhost ~]# free -g
              total        used        free      shared  buff/cache   available
Mem:             15           0          14           0           0          14
Swap:             7           0           7

[root@localhost ~]# du -sh /root
40K	/root
[root@localhost ~]# du -sh /home
196K	/home


#某个文件夹下的文件夹和文件大小
[root@localhost /]# du -h --max-depth=1 /opt/
39M     /opt/openssh-7.5p1
40M     /opt/

[root@localhost ~]# last root
root     pts/0        10.5.1.200       Fri Dec 24 11:31   still logged in   
root     tty1                          Fri Dec 24 10:28 - 10:28  (00:00)    
root     tty1                          Fri Dec 24 10:23 - 10:25  (00:02)    
root     tty1                          Thu Jun 10 09:50 - 09:50  (00:00)    
root     pts/0        192.168.0.200    Wed Jun  9 16:32 - crash  (17:18)    
root     pts/0        192.168.0.200    Fri Jun  4 16:18 - 16:20  (00:01)    
root     pts/0        192.168.0.201    Mon May 10 18:13 - 20:05  (01:52)    
root     pts/0        192.168.0.201    Mon May 10 17:04 - 17:49  (00:45)    
root     pts/0        192.168.0.200    Fri Apr 30 17:17 - 10:47  (17:30)    
root     pts/0        192.168.0.201    Wed Apr 21 18:46 - 19:54  (01:08)    
root     pts/0        192.168.0.201    Tue Apr 20 17:54 - 21:27  (03:32)    
root     pts/0        192.168.0.201    Tue Apr 20 16:45 - crash  (00:04)    
root     pts/0        192.168.0.201    Thu Apr 15 17:33 - 20:51  (03:18)    
root     tty1                          Thu Apr 15 16:33 - 16:34  (00:01)    
root     tty1                          Thu Apr 15 16:22 - 16:29  (00:06)    

wtmp begins Thu Apr 15 16:13:08 2021

[root@localhost ~]# cut -d: -f1 /etc/passwd
root
bin
daemon
adm
lp
sync
shutdown
halt
mail
operator
games
ftp
nobody
systemd-network
dbus
polkitd
sshd
postfix
chrony
ntp
tcpdump
unbound
rpc
qemu
gluster
radvd
tss
rpcuser
nfsnobody
saslauth
cockpit-ws