1. CentOS8设置中文字符集#

在使用Cent8的过程中，不能像设置Cent7的字符集那样进行下载。8的设置方式如下（亲自实践过）:

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dnf install glibc-langpack-zh.x86_64  #安装中文支持
echo LANG=zh_CN.UTF-8 > /etc/locale.conf #修改系统的字符集
source /etc/locale.conf #使立即生效

参考博客CentOS8中文支持

2. 查看Linux版本#

对于RedHat版本的linux,可以使用如下命令：

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# cat /etc/redhat-release

结果：

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[root@c071060a0213 /]# cat /etc/redhat-release
CentOS Linux release 8.1.1911 (Core)

参考博客

3. grep的基本使用#

3.1 获取匹配模式的上下指定行数#

在平时工作中，有时候只想获取匹配模式的上面5行或下面5行，那么如何实现呢？首先看一下man手册。

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# man grep
得到如下部分：
   Context Line Control
       -A NUM, --after-context=NUM
              Print NUM lines of trailing context after matching lines.  Places a line containing a group separator (described under --group-separator)
              between contiguous groups of matches.  With the -o or --only-matching option, this has no effect and a warning is given.

       -B NUM, --before-context=NUM
              Print NUM lines of leading context before matching lines.  Places a line containing a group separator (described under --group-separator)
              between contiguous groups of matches.  With the -o or --only-matching option, this has no effect and a warning is given.

       -C NUM, -NUM, --context=NUM
              Print NUM lines of output context.  Places a line containing a group separator (described  under  --group-separator)  between  contiguous
              groups of matches.  With the -o or --only-matching option, this has no effect and a warning is given.

举例：

有一个名为testb的文件内容如下：

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aaaaaaaa
dddddddd
ffffffff
gggggggg
hhhhhhhh
first=before
hello
first=after
jjjjjjjj
kkkkkkkk
llllllll
qqqqqqqq
wwwwwwww
eeeeeeee
rrrrrrrr
tttttttt
yyyyyyyy
uuuuuuuu
iiiiiiii
oooooooo
pppppppp
second=before
hello
second=after
zzzzzzzz
xxxxxxxx
cccccccc
vvvvvvvv
bbbbbbbb
nnnnnnnn
mmmmmmmm

我们想要获取hello前后各一行的数据

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[geneplus@bogon software]$ less testb | grep -1 'hello'
first=before
hello
first=after
--
second=before
hello
second=after

其他试用方式如下：

  • grep -5 ‘parttern’ inputfile =打印匹配行的前后5行

  • grep -C 5 ‘parttern’ inputfile =打印匹配行的前后5行

  • grep -A 5 ‘parttern’ inputfile =打印匹配行的后5行

  • grep -B 5 ‘parttern’ inputfile =打印匹配行的前5行

参考博客