用途

tail命令主要用于取出后边几行

全称

tail命令的全称即为tail(尾巴)

参数

-n :后边接数字，代表显示几行的意思

-f :循环读取

-q :不显示处理信息

-v :显示详细的处理信息

案例

案例一：显示文件最后5行内容

[root@bigdata ~]# tail -5 /etc/man_db.conf

#

#---------------------------------------------------------

# Flags.

# NOCACHE keeps man from creating cat pages.

#NOCACHE

案例二：循环查看文件内容

[root@bigdata /]# ping localhost >test.txt &

[4] 9944

[root@bigdata /]# tail -f test.txt

64 bytes from localhost (127.0.0.1): icmp_seq=1791 ttl=64 time=0.112 ms

64 bytes from localhost (127.0.0.1): icmp_seq=1792 ttl=64 time=0.161 ms
  bytes from localhost (127.0.0.1): icmp_seq=1793 ttl=64 time=0.166 ms

64 bytes from localhost (127.0.0.1): icmp_seq=1794 ttl=64 time=0.133 ms

….

想要结束按CTRL+C即可

案例三：从第5行开始显示文件

[root@bigdata /]# tail -n +5 /etc/man_db.conf

# their PATH environment variable. For details see the manpath(5) man page.

#

# Lines beginning with `#' are comments and are ignored. Any combination of

# tabs or spaces may be used as `whitespace' separators.

#

# There are three mappings allowed in this file:

# --------------------------------------------------------

# MANDATORY_MANPATH            manpath_element

# MANPATH_MAP        path_element    manpath_element

# MANDB_MAP        global_manpath    [relative_catpath]

#---------------------------------------------------------

……