linux三剑客——sed

原创

p00rguy 2023-07-18 17:56:21 ©著作权

文章标签 sed 正则表达式 git 文章分类 Java 后端开发 yyds干货盘点

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linux三剑客——sed

简介

Linux三剑客主打信息处理，三剑合璧，几乎能满足你所有的信息需求。其中，grep专攻查找，sed精通编辑，awk主打分隔提取。

sed

sed是操作、过滤和转换文本内容的强大工具，常用功能增删改查，过滤，取行。

sed从流或文件中读取内容在**模式空间（缓冲区）**中，读取一行处理一行，并将处理后的内容输出。

命令格式

sed [选项] ''操作' 文件名 或者 文件流 | sed [选项] '操作'

操作选项

p: 打印，可指定行、也支持正则表达式；需配合-n，否则会叠加默认输出，输出两次。

默认输出

# 输出clean.log内容
[root@prod-pve-packet-gitlab-runner-003 czx]# sed -n  'p' clean.log
[20230620-082401]: less than 50%, do nathing
[20230620-08:26:01]: less than 50%, do nathing
[20230620-08:27:01]: less than 50%, do nathing
[20230621-03:00:01]: less than 50%, do nathing
[20230624-11:00:01]: less than 50%, do nathing
[20230701-11:00:01]: less than 50%, do nathing
[20230708-03:00:01]: less than 50%, do nathing
[20230715-03:00:01]: less than 50%, do nathing

指定行

# 输出第一行
[root czx]# sed -n  '1p' clean.log
[20230620-082401]: less than 50%, do nathing

# 输出3-6行
[root czx]# sed -n  '3,6p' clean.log
[20230620-08:27:01]: less than 50%, do nathing
[20230621-03:00:01]: less than 50%, do nathing
[20230624-11:00:01]: less than 50%, do nathing
[20230701-11:00:01]: less than 50%, do nathing

正则表达式

# 输出[20230620开头的行
[root czx]# sed -n  '/^\[20230620/p' clean.log
[20230620-082401]: less than 50%, do nathing
[20230620-08:26:01]: less than 50%, do nathing
[20230620-08:27:01]: less than 50%, do nathing

=: 打印行号

# 输出行号
[root@prod-pve-packet-gitlab-runner-003 czx]# sed '=' clean.log
1
[20230620-082401]: less than 50%, do nathing
2
[20230620-08:26:01]: less than 50%, do nathing
3
[20230620-08:27:01]: less than 50%, do nathing
4
[20230621-03:00:01]: less than 50%, do nathing
5
[20230624-11:00:01]: less than 50%, do nathing
6
[20230701-11:00:01]: less than 50%, do nathing
7
[20230708-03:00:01]: less than 50%, do nathing
8
[20230715-03:00:01]: less than 50%, do nathing

l: 打印文本+ASCII字符

# 打印文本+ASCII字符
[root czx]# sed -n 'l' clean.log
[20230620-082401]: less than 50%, do nathing$
[20230620-08:26:01]: less than 50%, do nathing$
[20230620-08:27:01]: less than 50%, do nathing$
[20230621-03:00:01]: less than 50%, do nathing$
[20230624-11:00:01]: less than 50%, do nathing$
[20230701-11:00:01]: less than 50%, do nathing$
[20230708-03:00:01]: less than 50%, do nathing$
[20230715-03:00:01]: less than 50%, do nathing$

s: 替换指定字符（替换），写法为s/需要替换的字符串/替换后的字符串/替换标记，当然，这只是在模式空间中处理，不会改变源文件，改变源文件可以加上-i

替换标记:

g：表示要替换所有匹配的行。
w：将替换后的结果保存到文档。
n：1-512，表示指定要替换的字符串出现第几次时才进行替换。
w file：将缓冲区中的内容写到指定的file文件中。
&：用正则表达式匹配的内容进行替换。
\n：匹配第n个子串，该子串之前在pattern中用\(\)指定。
\：转义。

# 替换所有的less为more
[root@prod-pve-packet-gitlab-runner-003 czx]# sed 's/less/more/g' clean.log
[20230620-082401]: more than 50%, do nathing
[20230620-08:26:01]: more than 50%, do nathing
[20230620-08:27:01]: more than 50%, do nathing
[20230621-03:00:01]: more than 50%, do nathing
[20230624-11:00:01]: more than 50%, do nathing
[20230701-11:00:01]: more than 50%, do nathing
[20230708-03:00:01]: more than 50%, do nathing
[20230715-03:00:01]: more than 50%, do nathing

# 替换第一次出现的less为more
[root@prod-pve-packet-gitlab-runner-003 czx]# sed 's/less/more/1' clean.log
[20230620-082401]: more than 50%, do nathing
[20230620-08:26:01]: more than 50%, do nathing
[20230620-08:27:01]: more than 50%, do nathing
[20230621-03:00:01]: more than 50%, do nathing
[20230624-11:00:01]: more than 50%, do nathing
[20230701-11:00:01]: more than 50%, do nathing
[20230708-03:00:01]: more than 50%, do nathing
[20230715-03:00:01]: more than 50%, do nathing

d：删除指定的行（删除）。

a：在指定的行上一行增加一行指定内容（增加）。

i：在指定的上一行插入一行指定内容（插入）。

c：将选定行内容替换为指定内容（替换）。

y：字符转换，转换之后的字符长度必须相同。