-A : 相当于-vET 的整合参数，可列出一些特殊字符，而不是空白而已
-b ：列出行号，仅针对非空白行做行号显示，空白行不标行号
-E ：将结尾的断行字符$显示出来
-n : 打印行号，连同空白行也会有行号，与-b的参数不同

[root@iZ2zehkwp9rwg4azsvnjbuZ whx]# cat cattest.txt
test cat command
jaywei
#####

[root@iZ2zehkwp9rwg4azsvnjbuZ whx]# cat -n cattest.txt 1    test cat command   2    jaywei 3       4    #####

[root@iZ2zehkwp9rwg4azsvnjbuZ whx]# tac  cattest.txt  #####   jaywei  test cat command

head [OPTION]... FILE... -n<行数> 显示的行数  -q 隐藏文件名    -v 显示文件名    -c<字节> 显示字节数

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# head -n 12  sentinel.conf
# Example sentinel.conf
# *** IMPORTANT ***
#
# By default Sentinel will not be reachable from interfaces different than
# localhost, either use the 'bind' directive to bind to a list of network
# interfaces, or disable protected mode with "protected-mode no" by
# adding it to this configuration file.
#
# Before doing that MAKE SURE the instance is protected from the outside
# world via firewalling or other means.
#

tail [参数] [文件]
-f 循环读取
-q 不显示处理信息
-v 显示详细的处理信息
-c<数目> 显示的字节数
-n<行数> 显示文件的尾部 n 行内容

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# tail -n 12  sentinel.conf
# <role> is either "leader" or "observer"
#
# The arguments from-ip, from-port, to-ip, to-port are used to communicate
# the old address of the master and the new address of the elected slave
# (now a master).
#
# This script should be resistant to multiple invocations.
#
# Example:
#
# sentinel client-reconfig-script mymaster /var/redis/reconfig.sh

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# tail -f sentinel.conf
# The arguments from-ip, from-port, to-ip, to-port are used to communicate
# the old address of the master and the new address of the elected slave
# (now a master).
#
# This script should be resistant to multiple invocations.
#
# Example:
#
# sentinel client-reconfig-script mymaster /var/redis/reconfig.sh
<==要等到输入[ctrl]-c 之后才离开tail 这个命令的检测

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# tail -f sentinel.conf | grep redis
# sentinel client-reconfig-script mymaster /var/redis/reconfig.sh
<==要等到输入[ctrl]-c 之后才离开tail 这个命令的检测

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# more sentinel.conf
# Example sentinel.conf
...(中间省略) ...
# Note that whatever is the ODOWN quorum, a Sentinel will require to
# be elected by the majority of the known Sentinels in order to
# start a failover, so no failover can be performed in minority.
#
# Slaves are auto-discovered, so you don't need to specify slaves in
--More--(29%)

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# more -10 sentinel.conf
# Example sentinel.conf
...(此处省略)...
# Before doing that MAKE SURE the instance is protected from the outside
--More--(4%)

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# more -10 sentinel.conf
# Example sentinel.conf
...(此处省略)...
# protected-mode no
# port <sentinel-port>
# The port that this sentinel instance will run on
--More--(7%)

# *** IMPORTANT ***
...(此处省略)...
# Before doing that MAKE SURE the instance is protected from the outside
# world via firewalling or other means.
--More--(5%)

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# 

[root@iZ2zehkwp9rwg4azsvnjbuZ redis-4.0.7]# more -10  sentinel.conf
# Example sentinel.conf
...(此处省略)...
# Before doing that MAKE SURE the instance is protected from the outside
/sentinel  输入/之后，光标就会自动跑到最下面一行等待输入

# Before doing that MAKE SURE the instance is protected from the outside
/sentinel
...skipping
# protected-mode no
# port <sentinel-port>
# The port that this sentinel instance will run on
port 26379
# sentinel announce-ip <ip>
# sentinel announce-port <port>
#
/
...skipping
# Example:
#
# sentinel announce-ip 1.2.3.4
# dir <working-directory>
# Every long running process should have a well-defined working directory.
# For Redis Sentinel to chdir to /tmp at startup is the simplest thing
# for the process to don't interfere with administrative tasks such as
# unmounting filesystems.
--More--(23%)

less sentinel.conf

less + file-name + 命令 F =  tail -f + file-name