2. 案例
1. 案例¶
1. 准备案例数据¶
cd /tmp
vim cp.txt
My name is chupeng.
I like linux.
I like playing computer game.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
2.输出文件的第2，3行¶
#1. sed默认输出所有结果
sed '2,3p' cp.txt
#2. 加上-n参数则只输出第2，3行
sed -n '2,3p' cp.txt
sed -n '2,3'p cp.txt
#1.默认输出所有内容
root@baiduyun:/tmp# sed '2,3p' cp.txt
My name is chupeng.
I like linux.
I like linux.
I like playing computer game.
I like playing computer game.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
#2.只输出2和3行，p在引号内外皆可！
root@baiduyun:/tmp# sed -n '2,3p' cp.txt
I like linux.
I like playing computer game.
#3.只输出2和3行
root@baiduyun:/tmp# sed -n '2,3'p cp.txt
I like linux.
I like playing computer game.
3. 输出第2行及其往后3行的内容¶
sed -n "2,+3p" cp.txt
root@baiduyun:/tmp# sed -n "2,+3p" cp.txt
I like linux.
I like playing computer game.
My qq is 747356101.
My wechat is cpu19900130.
4. 输出含有linux的行，类似 grep ！¶
sed -n "/linux/p" cp.txt
root@baiduyun:/tmp# sed -n "/linux/p" cp.txt
I like linux.
5. 删除含有game的行（内存中修改，不修改原文件）¶
sed -n "/game/d" cp.txt
# 查看删除后的结果
sed "/game/d" cp.txt
# 删除默认不输出内容
root@baiduyun:/tmp# sed -n "/game/d" cp.txt
root@baiduyun:/tmp#
# 查看删除后的结果，此结果是在内存中，原文件未修改！
root@baiduyun:/tmp# sed "/game/d" cp.txt
My name is chupeng.
I like linux.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
6. 删除含有game的行（直接修改原文件）¶
sed -i "/game/d" cp.txt
cat cp.txt
root@baiduyun:/tmp# cat cp.txt
My name is chupeng.
I like linux.
I like playing computer game. # 执行后，原文件此行消失
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
root@baiduyun:/tmp#
root@baiduyun:/tmp# sed -i "/game/d" cp.txt
root@baiduyun:/tmp#
root@baiduyun:/tmp# cat cp.txt
My name is chupeng.
I like linux.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
7. 删除第4行到结尾的内容¶
sed '4,$d' cp.txt
root@baiduyun:/tmp# sed '4,$d' cp.txt
My name is chupeng.
I like linux.
My qq is 747356101.
8. 将My替换为His(常用于快速修改配置文件！加上参数-i直接修改文件！)¶
sed 's/My/His/g' cp.txt
root@baiduyun:/tmp# sed 's/My/His/g' cp.txt
His name is chupeng.
I like linux.
His qq is 747356101.
His wechat is cpu19900130.
His website is https://chupeng.site.
9. 替换His->My，同时替换掉QQ号为88888¶
sed -e 's/His/My/g' -e 's/747356101/88888/g' cp.txt
root@baiduyun:/tmp# sed -e 's/His/My/g' -e 's/747356101/88888/g' cp.txt
My name is chupeng.
I like linux.
My qq is 88888.
My wechat is cpu19900130.
My website is https://chupeng.site.
10. 在第2行后追加内容，并写入到文件¶
sed -i '2a I am using sed command.' cp.txt
root@baiduyun:/tmp# sed '2a I am using sed command.' cp.txt
My name is chupeng.
I like linux.
I am using sed command.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
root@baiduyun:/tmp# sed -i '2a I am using sed command.' cp.txt
root@baiduyun:/tmp#
root@baiduyun:/tmp# cat cp.txt
My name is chupeng.
I like linux.
I am using sed command.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
11. 在第4行前插入2行内容¶
sed -i '4i My linux is good.\nI like pretty girl.' cp.txt
root@baiduyun:/tmp# sed -i '4i My linux is good.\nI like pretty girl.' cp.txt
root@baiduyun:/tmp#
root@baiduyun:/tmp# cat cp.txt
My name is chupeng.
I like linux.
I am using sed command.
My linux is good.
I like pretty girl.
My linux is good.
I like pretty girl.
My qq is 747356101.
My wechat is cpu19900130.
My website is https://chupeng.site.
12. 在每一行下，添加一行内容¶
sed "a -------------------" cp.txt
root@baiduyun:/tmp# sed "a -------------------" cp.txt
My name is chupeng.
-------------------
I like linux.
-------------------
I am using sed command.
-------------------
My linux is good.
-------------------
I like pretty girl.
-------------------
My linux is good.
-------------------
I like pretty girl.
-------------------
My qq is 747356101.
-------------------
My wechat is cpu19900130.
-------------------
My website is https://chupeng.site.
-------------------
5. sed配合正则表达式企业案例¶
1. 取出Linux的IP地址¶
# 思路：
#1.先取出第2行
ifconfig |sed -n '2p'
#2. 找到第2行后，去掉ip之前的内容
ifconfig |sed -n '2p' | sed 's/^.*inet//'
#3. 去掉ip之后的内容，即可得到IP！
ifconfig |sed -n '2p' | sed 's/^.*inet//' |sed 's/net.*$//'
#4.也可以使用-e进行多次编辑
ifconfig|sed -n -e '2s/^.*inet//g' -e '2s/net.*$//g'p
root@baiduyun:/tmp# ifconfig |sed -n '2p'
inet 172.18.0.1 netmask 255.255.0.0 broadcast 172.18.255.255
root@baiduyun:/tmp# ifconfig |sed -n '2p' | sed 's/^.*inet//'
172.18.0.1 netmask 255.255.0.0 broadcast 172.18.255.255
root@baiduyun:/tmp#
root@baiduyun:/tmp# ifconfig |sed -n '2p' | sed 's/^.*inet//' |sed 's/net.*$//'
172.18.0.1
root@baiduyun:/tmp# ifconfig|sed -n -e '2s/^.*inet//g' -e '2s/net.*$//g'p
172.18.0.1
6. 取出nginx访问日志中指定时间段的日志！¶
cd /var/log/nginx
cat access.log.1
# 16/Jan/2022:09:14:47
# 16/Jan/2022:09:19:49
sed -n '/16\/Jan\/2022:09:14:47/,/16\/Jan\/2022:09:19:49/'p access.log.1
# 使用错误日志代替
root@baiduyun:/var/log/nginx# cat error.log.1
2022/02/09 21:20:10 [notice] 3563674#3563674: signal process started
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:10 [emerg] 3561765#3561765: still could not bind()
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: still could not bind()
2022/02/09 21:20:41 [notice] 3564633#3564633: signal process started
# 取出20：17-20：41时间段内的内容
# 2022/02/09 21:20:17
# 2022/02/09 21:20:41
# sed -n '/2022\/02\/09 21:20:17/,/2022\/02\/09 21:20:41/'p error.log.1
root@baiduyun:/var/log/nginx# sed -n '/2022\/02\/09 21:20:17/,/2022\/02\/09 21:20:41/'p error.log.1
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to 0.0.0.0:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: bind() to [::]:8080 failed (98: Address already in use)
2022/02/09 21:20:17 [emerg] 3563955#3563955: still could not bind()
2022/02/09 21:20:41 [notice] 3564633#3564633: signal process started
最后更新:
2022-02-15 08:59:03