Linux 中【sed】 命令快速参考
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2022-04-10 15:00
目录
一、sed 命令简介
输入流
输出流
二、sed 命令格式
常用选项
常用命令
正则表达式
三、使用举例
内容显示
内容替换
内容添加
行删除
行替换
内容搜寻
级联操作
GNU 官方文档
一、sed 命令简介
sed
命令的全称是:stream editor
(数据流编辑器),言下之意就是对流式数据进行处理。
主要使用场景:对文本中的特定字符串进行替换或者删除。
它每次从输入流中读取一行内容,去掉末尾的换行符之后,放在内部的一个缓冲区中,
然后根据命令参数对缓冲区中数据进行处理,最后把处理后数据输出到输出流中。
输入流可以是:终端输入内容、管道、文件;
输出流可以是:终端输出、文件。
1. 输入流:终端输入
$ sed 's/my/your/g' -
这条指令意思是:把输入字符中的字符串 "my" 替换成 "your"。
最后的 -
表示sed
命令将会读取用户的输入内容,用户输入完一行内容(按下回车):
this is my book
此时,sed
就会接收到这行内容,然后进行处理,最后把处理结果输出到终端屏幕上:
this is your book
当处理完这行内容之后,继续等待读取用户的下一行输入内容。
2. 输入流:管道
$ echo "this is my book" | sed 's/my/your/g'
this is your book
echo
命令的输出结果,经过管道被sed
命令读取,然后进行处理,最后输出到终端屏幕上。
3. 输入流:文件
测试文件file.txt
中内容如下:
This is my book
This is my box
把文件中字符串my
替换成your
。
$ sed 's/my/his/g' file.txt
This is your book
This is your box
上面这条指令把处理结果输出到终端屏幕上,对file.txt
文件本身并没有任何改动。
如果想直接对文件进行操作,那么就需要加上一个选项:-i
,完整指令如下:
$ sed -i 's/my/his/g' file.txt
4. 输出流
上面的几个示例中, sed
命令直接把输出流(处理结果)输出到终端屏幕上。
除此之外,sed
还可以把输出流通过管道传递给其它指令,例如:
$ echo "this is my book" | sed 's/my/your/g' | wc
1 4 18
还可以让sed
把处理结果重导向到一个文件中:
$ echo "this is my book" | sed 's/my/your/g' > test.txt
$ cat test.txt
this is your book
或者是直接在指令中通过 w
标志指定输出文件:
$ echo "this is my book" | sed 's/my/your/gw test.txt'
$ cat test.txt
this is your book
二、sed 命令格式
$ sed [选项] [命令] [输入文件]
常用选项:
-i: 直接对文件内容进行修改;
-e: 直接在指令列模式上进行动作编辑;
-f: 执行一个文件内的 sed 命令;
-n: 使用安静模式;
-r: 使用扩展的正则表达式来进行内容匹配;
常用命令:
a: 在当前选择行的后面追加一行;
i: 在当前选择行的前面追加一行;
c: 把当前选择行内容进行替换;
d: 删除当前选择的行;
s: 对当前行中选择的字符串进行替换;
g: 在当前选择行中进行全部替换;
p: 打印选择的行;
支持的正则表达式:
^: 行首定位符;
$: 行尾定位符;
.: 匹配除了换行符之外的其他任意一个字符;
+: 匹配前面一个字符重复 1 次或多次;
*: 匹配前面一个字符重复 0 次或多次;
{i}: 匹配前面一个字符重复 i 次;
{i,}: 匹配前面一个字符重复至少 i 次;
{i,j}: 匹配前面一个字符重复 i ~ j 次;
\n: 匹配换行符
三、使用举例
为了便于演示,以下示例中的输入流来自文件,输出到终端屏幕上。
测试文件file.txt
内容:
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
如果需要直接对文件进行修改的话,加上
-i
选项即可。
内容显示
示例:显示文件中第2
行:
$ sed -n '2p' file.txt
line2: That is your book, a nice book.
示例:显示文件中第2 ~ 4
行:
$ sed -n '2,4p' file.txt
line2: That is your book, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
示例:显示文件中除了2 ~ 4
行之外的其它行:
$ sed '2,4d' file.txt
line1: This is my book, a nice book.
line5: Welcome to www.linuxbar.net!
内容替换
示例:把每一行中的book
替换成picture
:
$ sed 's/book/picture/' file.txt
line1: This is my picture, a nice book.
line2: That is your picture, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
可以看到:第1、2
行中只有第一个book
字符串被替换了,后面的那个没有被替换。
示例:如果要全部替换,需要加上g
标志,如下:
$ sed 's/book/picture/g' file.txt
line1: This is my picture, a nice picture.
line2: That is your picture, a nice picture.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
内容替换的格式是:sed 's/old/new/g' flie
,使用斜杠/
进行分割,在处理文件路径时就显得很麻烦,例如:
示例:把路径分隔符进行替换:
$ echo "/home/tmp" | sed 's/\//\\/g'
\home\tmp
此时,可以使用除了换行符之外的其他任意字符来替代,例如:
$ echo "/home/tmp" | sed 's#/#\\#g'
\home\tmp
\:因为反斜杠自身是一个特殊的字符,所以需要进行转义。
另外一个问题:sed
把每一行都输出到屏幕上了,包括没有匹配的那些行。
如何只显示处理的那些行呢?
示例:把每一行中的book
替换成picture
: ,但是只显示处理的行:
$ sed -n 's/book/picture/gp' file.txt
line1: This is my picture, a nice picture.
line2: That is your picture, a nice picture.
示例:将每一行中的第2
个book
替换成picture
:
$ $ sed -n 's/book/picture/2p' file.txt
line1: This is my book, a nice picture.
line2: That is your book, a nice picture.
示例:将2 ~ 3
行中的book
替换成picture
:
$ sed '2,3s/book/picture/g' file.txt
line1: This is my book, a nice book.
line2: That is your picture, a nice picture.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
示例:将 2 ~ 最后一行
中的30
替换成100
:
$ sed '2,$s/30/100/g' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 100 years old.
line4: You are 100 years old.
line5: Welcome to www.linuxbar.net!
示例:找出包含字符years
的那些行,将这些行中的30
替换成100
:
$ sed '/years/s/30/100/g' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 100 years old.
line4: You are 100 years old.
line5: Welcome to www.linuxbar.net!
示例:找出满足 Th[is|at]
模式的那些行,将这些行中的book
替换成picture
:
$ sed '/Th[is|at]/s/book/picture/g' file.txt
line1: This is my picture, a nice picture.
line2: That is your picture, a nice picture.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
示例:找出包含www
和 net
的那些行,把bar
替换成BAR
:
$ sed '/www/,/net/ s/bar/BAR/' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxBAR.net!
示例:忽略大小写,把每行中的 OLD
替换成###
:
$ sed 's/OLD/###/i' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 30 years ###.
line4: You are 30 years ###.
line5: Welcome to www.linuxbar.net!
示例:从第2
行开始一直到包含am
行之间的所有行中,把30
替换成100
:
$ sed '2,/am/s/30/100/' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 100 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
示例:从包含am
开始的那行开始一直到最后一行,把其中的数字替换成#
:
$ sed '/am/,$ s/[0-9]/#/g' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line#: I am ## years old.
line#: You are ## years old.
line#: Welcome to www.linuxbar.net!
示例:把每一行中的小写字母a
替换成大写字符A
, 小写字母b
替换成大写字符B
:
$ sed 'y/ab/AB/' file.txt
line1: This is my Book, A nice Book.
line2: ThAt is your Book, A nice Book.
line3: I Am 30 yeArs old.
line4: You Are 30 yeArs old.
line5: Welcome to www.linuxBAr.net!
内容添加
示例:在第2
行的前面添加一行内容:
$ sed '2i\new line: hello' file.txt
line1: This is my book, a nice book.
new line: hello
line2: That is your book, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
示例:在第2
行后面面添加一行内容:
$ sed '2a\new line: hello' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
new line: hello
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
行删除
示例:删除2 ~ 4
行:
$ sed '2,4d' file.txt
line1: This is my book, a nice book.
line5: Welcome to www.linuxbar.net!
示例:删除包含字符串book
的行:
$ sed '/book/d' file.txt
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
示例:删除不包含字符串book
的行:
$ sed '/book/!d' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
示例:删除空白行,包括空格
$ sed '/^\s*$/d' file.txt
line1: This is my book, a nice book.
line2: That is your book, a nice book.
line3: I am 30 years old.
line4: You are 30 years old.
line5: Welcome to www.linuxbar.net!
行替换
示例:把2 ~ 4
行替换成delete
:
$ sed '2,4 cdelete' file.txt
line1: This is my book, a nice book.
delete
line5: Welcome to www.linuxbar.net!
内容搜寻
示例:查找哪些行包含字符串old
:
$ sed -n '/old/=' file.txt
3
4
示例:统计文件中一共有多少行:
$ sed -n '$=' file.txt
5
级联操作
示例:把2 ~ 4
行内容中的book
替换成picture
,30
替换成100
:
$ sed -n '2,4p' file.txt | sed 's/book/picture/g' | sed 's/30/100/g'
line2: That is your picture, a nice picture.
line3: I am 100 years old.
line4: You are 100 years old.
示例:把2 ~ 4
行内容中的book
替换成picture
,30
替换成100
:
$ sed -n '2,4p' file.txt | sed -e 's/book/picture/g' -e 's/30/100/g'
line2: That is your picture, a nice picture.
line3: I am 100 years old.
line4: You are 100 years old.