Java程序员必备：查看日志常用的linux命令

cat [-AbEnTv]参数：-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.txttest cat commandjaywei
#####

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

[root@iZ2zehkwp9rwg4azsvnjbuZ whx]# tac  cattest.txt#####
jayweitest 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

more [-dlfpcsu] [-num] [+/pattern] [+linenum] [fileNames..]参数：-num ：一次显示的行数-p ：不以卷动的方式显示每一页，而是先清除萤幕后再显示内容-c ： 跟 -p 相似，不同的是先显示内容再清除其他旧资料-s ： 当遇到有连续两行以上的空白行，就代换为一行的空白行+/pattern ： 在每个文档显示前搜寻该字串（pattern），然后从该字串之后开始显示-u ：不显示下引号 （根据环境变数 TERM 指定的 terminal 而有所不同）+num : 从第 num 行开始显示fileNames ：欲显示内容的文档，可为复数个数

[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 onport 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