一: sed 是什么?

sed 行编辑工具. sed , awk , grep 被称作文本三剑客.

二:sed 的命令语法

   sed [option]... '地址 编辑命令' FILE...

optin 的选项有:

-n: 静默模式，不显示模式空间中的内容
-r: 支持使用扩展正则表达式
-i: 修改原文件；
-e: sed -e "" -e "" -e "", sed "{COM1;COM2;COM3}"

填写地址方式:

行范围：
start_line[, end_line]
# sed -n '1,5p' test.txt    #从第一行到第五行打印出来
# sed -n '1,$p' test.txt    #从第一行到最后一行打印出来/patten1/,/patten2/: 第一次被pattern1匹配到的行开始，到第一次被pattern2匹配到的行结束之间的所有行；
# sed -n  '/\<and\>/,/\<or\>/p'  test.txt 特定行：
/pattern/ : 符合条件的特定行.
# sed -n '/all/p' test.pp无地址：全文

编辑命令

编辑命令：命令可在之前加!取反
p：打印
d: 删除
i \text: 行上方，text即为插入的内容
a \text: 行下方，text即为插入的内容
r /path/from/some_file: 读入文件
w /path/to/some_file: 把符合条件的行保存至指定的文件中
=: 显示符合条件行的行号
s///: s@@@    g:为全局替换  s///g

一些常见的几个命令

‘s / \ . $ / / g’ 删除以句点结尾的.
‘-e /abcd/d’      删除包含a b c d的行.
‘s / [ ][ ]* / [ ] / g’ 删除一个以上空格，用一个空格代替 此处的[] 指空格代替
‘s / ^ [ ] [ ] * / / g’ 删除行首空格
‘s / \ . [ ] [ ] * / [ ] / g’ 删除句点后跟一个或更多空格，代之以一个空格
‘/ ^ $ / d’ 删除空行
‘s / ^ . / / g’ 删除第一个字符
‘s / ^ \ / / / g’ 从路径中删除第一个/
‘S / ^ [ ] / / g’ 删除行首所有t a b键
‘s / [ ] * / / g’ 删除所有t a b键

三:增删换显几个练习

例:cat 1.txt

cat 1.txt12332###DISO###45.12^M
00332###LPSO###23.14^M
01299###USPD###34.46^M把所有是#的内容替换掉
sed  's/##*//' 1.txt12332DISO45.12^M
00332LPSO23.14^M
01299USPD34.46^M显示第2行内容sed -n '2p' 1.txt
00332###LPSO###23.14^M删除所有行首是0 的行内容
sed /^00*/d 1.txt
12332###DISO###45.12^M替换行首是0的内容为1
sed 's/^0/1/g' 1.txt
12332###DISO###45.12^M
10332###LPSO###23.14^M
11299###USPD###34.46^M替换行尾是特殊字符^M
sed 's/\^M$//g' 1.txt
12332###DISO###45.12
00332###LPSO###23.14
01299###USPD###34.46操作集合
cat 1.txt |sed 's/##*//g' | sed 's/\^M//g' | sed '2d' | sed '/^0/i hello' | sed '/^0/a word' | sed '1p'
12332DISO45.12
12332DISO45.12
hello
01299USPD34.46
word看到前两行是同样的内容输出,如果我们想要输出匹配的一行. 用-n 参数; 如果想要让上面的内容生效用-i 参数

四:打印行号

例 :cat 2.txt

 cat 2.txt The     honeysuckle band played all night long for only $90.
It was an evening of splendid art and company.
The office Dibble art played well.
The local nurse music P.Neave was in attendance.sed -e '/was/=' 2.txtThe     honeysuckle band played all night long for only $90.
2
It was an evening of splendid art and company.
The office Dibble art played well.
4
The local nurse music P.Neave was in attendance.如果只关心行号 把-e换成-n只显示匹配到的行和行号
sed -n -e '/was/p' -e '/was/=' 2.txtIt was an evening of splendid art and company.
2
The local nurse music P.Neave was in attendance.
4

五:读入文件内容,写入文件内容

cat 1.txt
12332###DISO###45.12^M
00332###LPSO###23.14^M
01299###USPD###34.46^Mcat 2.txtThe     honeysuckle band played all night long for only $90.
It was an evening of splendid art and company.
The office Dibble art played well.
The local nurse music P.Neave was in attendance.把2.txt中的内容读入1.txt第一行下面
sed '1r 2.txt' 1.txt12332###DISO###45.12^MThe     honeysuckle band played all night long for only $90.
It was an evening of splendid art and company.
The office Dibble art played well.
The local nurse music P.Neave was in attendance.
00332###LPSO###23.14^M
01299###USPD###34.46^M把1.txt第1行写入test.txt中
sed '1w test.txt' 1.txtcat test.txt
12332###DISO###45.12^M

六:在内容后面插入内容

例 :cat 3.txt

cat 3.txt
AC456
AC492169
AC9967
AC88345在数字最后插入 passwdsed 's/[0-9][0-9]*/& passwd/g' 3.txt
sed 's/[0-9][0-9]*/& passwd/g' 3.txtAC456 passwd
AC492169 passwd
AC9967 passwd
AC88345 passwd