查看当前用户
[root@mid ~]# w
10:08:13 up 33 days, 16:02, 1 user, load average: 1.40, 0.85, 0.79
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 xx.xx.xx.xx 09:45 5.00s 0.35s 0.01s w
查看所有用户
通用方法：直接查看/etc/passwd 文件后面第二个冒号的值大于1000时，这个就是一个用户.
- cat /etc/passwd
[root@mid ~]# cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
polkitd:x:999:998:User for polkitd:/:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
chrony:x:998:996::/var/lib/chrony:/sbin/nologin
saslauth:x:997:76:Saslauthd user:/run/saslauthd:/sbin/nologin
tcpdump:x:72:72::/:/sbin/nologin
clamupdate:x:996:993:Clamav database update user:/var/lib/clamav:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
clamscan:x:995:991:Clamav scanner user:/:/sbin/nologin
mailnull:x:47:47::/var/spool/mqueue:/sbin/nologin
smmsp:x:51:51::/var/spool/mqueue:/sbin/nologin
- cat /etc/passwd |cut -d: -f 1-3 ，信息简洁方便查看，推荐使用
[root@mid ~]# cat /etc/passwd |cut -d: -f 1-3
root:x:0
bin:x:1
daemon:x:2
adm:x:3
lp:x:4
sync:x:5
shutdown:x:6
halt:x:7
mail:x:8
operator:x:11
games:x:12
ftp:x:14
nobody:x:99
systemd-network:x:192
dbus:x:81
polkitd:x:999
sshd:x:74
postfix:x:89
chrony:x:998
saslauth:x:997
tcpdump:x:72
clamupdate:x:996
tss:x:59
clamscan:x:995
mailnull:x:47
smmsp:x:51
- lastlog 显示系统所有用户，包括系统用户
[root@mid ~]# lastlog
Username Port From Latest
root pts/0 xx.xx.xx.xxx Wed Oct 9 09:45:51 +0800 2024
bin **Never logged in**
daemon **Never logged in**
adm **Never logged in**
lp **Never logged in**
sync **Never logged in**
shutdown **Never logged in**
halt **Never logged in**
mail **Never logged in**
operator **Never logged in**
games **Never logged in**
ftp **Never logged in**
nobody **Never logged in**
systemd-network **Never logged in**
dbus **Never logged in**
polkitd **Never logged in**
sshd **Never logged in**
postfix **Never logged in**
chrony **Never logged in**
saslauth **Never logged in**
tcpdump **Never logged in**
clamupdate **Never logged in**
tss **Never logged in**
clamscan **Never logged in**
mailnull **Never logged in**
smmsp **Never logged in**
删除用户
userdel username
锁定、解锁用户
#锁定用户
usermod -L username
#解锁用户
usermod -U username
