less命令的作用与more十分相似，都可以用来浏览文字档案的内容，不同的是less命令允许用户向前或向后浏览文件，而more命令只能向前浏览。
用less命令显示文件时，用PageUp键向上翻页，用PageDown键向下翻页。要退出less程序，应按Q键。
(1)用法:
用法: less [选项参数] [文件参数]
(2)功能:
功能: less 与more命令类似，但可以通过翻页键查看上下页的内容
(3)选项参数:
1) -e: 文件内容显示完毕后，自动退出
2) -f: 强制显示文件
3) -g: 不加亮显示搜索到的所有关键词，仅显示当前显示的关键字，以提高显示速度
4) -l: 搜索时忽略大小写的差异
5) -N: 每一行行首显示行号
6) -s: 将连续多个空行压缩成一行显示
7) -S: 在单行显示较长的内容，而不换行显示
8) -x<数字>: 将TAB字符显示为指定个数的空格字符。
(4)实例:
1)[root@localhost Documents]# less less_text 在另一个进程页面中显示文本内容，按q键退出
[root@localhost Documents]# mv more_text1 less_text //将more_text1改名为less_text
[root@localhost Documents]# ll
总用量
-rw-r--r--. root root 5月 : less_text
[root@localhost Documents]# cat less_text //在当前终端中显示(和less命令显示的效果还是有差别的)
[root@localhost Documents]# less less_text //在另一个页面中显示文本
I am studing orders of Linux!
I am trying to write as many as lines of text! No matter how low you consider yourself,
there is always someone looking behind you,
hoping that they were that high! Something you want keep all the time,always you will lose! Never forget to say "thanks"! Hppay today,also,prepared for happiness in the future! Don't aim your success if you want it,just do what you love and believe and finally you will success! Maybe you can be laze man like a pig,but you can't feel free as it! I am a college school student!
I am planning to live and work in hangzhou or guangzhou!
I am from hefei anhui!
Enough,I have write too many words!
(END)
2)[root@localhost Documents]# ps -ef |less 显示已有进程信息
ID PID PPID C STIME TTY TIME CMD
root : ? :: /usr/lib/systemd/systemd --switched-root --system --deserialize
root : ? :: [kthreadd]
root : ? :: [ksoftirqd/]
root : ? :: [kworker/:0H]
root : ? :: [migration/]
root : ? :: [rcu_bh]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
root : ? :: [rcuob/]
:
.......//还有很多没有显示
3)[root@localhost Documents]# history | less 显示历史输入的进程信息
touch touch_test /home/sunjimeng/Document
cd /home/sunjimeng/Document
ll
cd /
touch touch_text /home/sunjimeng/Document/touch_test
cd /home/sunjimeng/Document
ll
rm touch_test
cd /
ls -l /home/sunjimeng/Document
touch /home/sunjimeng/Document/touch_test_file
cd home/sunjimeng/Document
ll
touch touch_test_file
ll
touch -t touch_test_file
ll
touch touch_test_file
ll
touch -t touch_test_file
ll
touch touch_test_file2
ll
touch -r touch_testfile touch_test_tile2
touch -r touch_test_file touch_test_file2
ll
touch -d "10 day ago" touch_test_file2
ll
touch -r touch_test_file touch_test_file2
ll
touch -d "10 days ago" touch_test_file2
ll
touch "10 days ago" touch_test_file
ll
:
4)[root@localhost Documents]# less less1 less2 查看多个文件（怎么切换下一个还不清楚）
root@localhost Documents]# cat >less1 <<EOF
> Lost means Get!
>
> No losing No getting!
>
> End!
> EOF
[root@localhost Documents]# cat >less2 <<EOF
> If you want keep,you always lose!
>
> Certainly It is!
> End!
> EOF
[root@localhost Documents]# ll
总用量
-rw-r--r--. root root 5月 : less1
-rw-r--r--. root root 5月 : less2
-rw-r--r--. root root 5月 : less_text
[root@localhost Documents]# less less1 less2
Lost means Get! No losing No getting! End!
less1 (file 1 of 2) (END) - Next: less2
5)[sunjimeng@localhost ~]$ netstat -tpnl |less 在另一个进程页面中分页显示信息，这里显示的是网络信息
[sunjimeng@localhost ~]$ netstat -tpnl |less
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0.0.0.0: 0.0.0.0:* LISTEN -
tcp 127.0.0.1: 0.0.0.0:* LISTEN -
tcp 127.0.0.1: 0.0.0.0:* LISTEN -
tcp6 ::: :::* LISTEN -
tcp6 ::: :::* LISTEN -
tcp6 ::: :::* LISTEN -
(5)其他:
1.全屏导航
ctrl + F - 向前移动一屏
ctrl + B - 向后移动一屏
ctrl + D - 向前移动半屏
ctrl + U - 向后移动半屏
2.单行导航
j - 向前移动一行
k - 向后移动一行
3.其它导航
G - 移动到最后一行
g - 移动到第一行
q / ZZ - 退出 less 命令
4.其它有用的命令
v - 使用配置的编辑器编辑当前文件
h - 显示 less 的帮助文档
&pattern - 仅显示匹配模式的行，而不是整个文件
5.标记导航
当使用 less 查看大文件时，可以在任何一个位置作标记，可以通过命令导航到标有特定标记的文本位置：
ma - 使用 a 标记文本的当前位置
'a - 导航到标记 a 处