Linux查看文件尾部内容命令-tail

[root@localhost ~]# tail /etc/passwd
systemd-bus-proxy:x:999:997:systemd Bus Proxy:/:/sbin/nologin
systemd-network:x:998:996:systemd Network Management:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
polkitd:x:997:995:User for polkitd:/:/sbin/nologin
abrt:x:173:173::/etc/abrt:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
chrony:x:996:994::/var/lib/chrony:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
user1:x:1000:1000::/home/user1:/bin/bash

[root@localhost ~]# tail -c 50 /etc/passwd
/nologin
user1:x:1000:1000::/home/user1:/bin/bash
[root@localhost ~]# 

[root@localhost ~]# tail -5 /etc/passwd 
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
chrony:x:996:994::/var/lib/chrony:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
user1:x:1000:1000::/home/user1:/bin/bash
[root@localhost ~]# tail -n 5 /etc/passwd  
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
chrony:x:996:994::/var/lib/chrony:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
user1:x:1000:1000::/home/user1:/bin/bash

[root@localhost ~]# tail -f /var/log/messages 
Sep  2 15:05:39 localhost systemd: Startup finished in 21.320s (kernel) + 2.033s (initrd) + 9.242s (userspace) = 32.596s.
Sep  2 15:05:42 localhost chronyd[716]: Selected source 185.134.197.4
Sep  2 15:05:57 localhost systemd: Created slice User Slice of root.
Sep  2 15:05:57 localhost systemd: Starting User Slice of root.
Sep  2 15:05:57 localhost systemd: Started Session 1 of user root.
Sep  2 15:05:57 localhost systemd-logind: New session 1 of user root.
Sep  2 15:05:57 localhost systemd: Starting Session 1 of user root.
Sep  2 15:07:59 localhost chronyd[716]: Source 108.59.2.24 replaced with 173.255.246.13
Sep  2 15:20:09 localhost systemd: Starting Cleanup of Temporary Directories...
Sep  2 15:20:09 localhost systemd: Started Cleanup of Temporary Directories.
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[root@localhost ~]# tailf /var/log/messages 
Sep  2 15:05:39 localhost systemd: Startup finished in 21.320s (kernel) + 2.033s (initrd) + 9.242s (userspace) = 32.596s.
Sep  2 15:05:42 localhost chronyd[716]: Selected source 185.134.197.4
Sep  2 15:05:57 localhost systemd: Created slice User Slice of root.
Sep  2 15:05:57 localhost systemd: Starting User Slice of root.
Sep  2 15:05:57 localhost systemd: Started Session 1 of user root.
Sep  2 15:05:57 localhost systemd-logind: New session 1 of user root.
Sep  2 15:05:57 localhost systemd: Starting Session 1 of user root.
Sep  2 15:07:59 localhost chronyd[716]: Source 108.59.2.24 replaced with 173.255.246.13
Sep  2 15:20:09 localhost systemd: Starting Cleanup of Temporary Directories...
Sep  2 15:20:09 localhost systemd: Started Cleanup of Temporary Directories.
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