04-linux Text Processing-sed

• The SED software loops through a file or pipe to read a line, processing one line, and outputting one line.
• Mode space, the internal SED software is a temporary cache for storing the content read.

Software version

sed --versionGNU sed version 4.2.1

Syntax format

sed [option] [sed commands] [file]sed [选项]   [sed命令]      [输入文件]

SED options

Options	function
-N	Using quiet mode, in general, all STDIN are output to the screen, adding-n will only print lines that have been specially processed by sed
-E	Multiple edits, and command order affects results
-F	Specify an sed script file to execute on the command line
-R	Sed uses extended regular
-I.	Directly modify the contents of the document read, not output on the screen

SED command

Command	Description
A	Add one or more rows after the current line
C	Modify (replace) text in the current line with new text
D	Delete Row
I	Insert text before the current line
H	Copy the contents of the pattern space to the staging buffer
H	Append the contents of the pattern space to the staging buffer
G	Take out the contents of the staging buffer, copy it to the pattern space, and overwrite the original content
G	Take out the contents of the staging buffer, copy it to the schema space, append to the original content
L	List non-printable characters
P	Print Line
N	Read in the next input line and start processing from the next command instead of the first command
Q	End or exit sed
R	Reading input rows from a file
！	Apply commands to all rows that are unexpected for the selected row
S	Replace one string with another
G	Global substitution within a row
P	Print Line
W	Writing rows to a file
X	Swap the contents of the staging buffer with the pattern space
Y	Converts a character to another character (cannot use the Y command on a regular expression)

SED address range display

• SED software can process single or multiple lines.
• If you do not specify an address range before the SED command, all rows are matched by default.
• Usage: n1[,n2]{sed-commands}
  • Addresses are separated by commas, and n1,n2 can be represented by numbers, regular expressions, or a combination of the two.

Example	function
10i	Action on line 10th
10,20i	For 10 to 20 rows, including 10th, 20 rows
10,+20i	For 10 to 30 (10+20) line operations, including 10th, 30 rows
1~2i	,...... to 1,3,5,7 Row operations
Ten, $i	Action on 10 to last line ($ for last row), including line 10th
/oldboy/i	Row operations on matching Oldboy
/oldboy/,/alex/i	Rows to match Oldboy to the row operation of Alex
/oldboy/, $i	Line-to-last line action on matching Oldboy
/oldboy/,10i	The row to line 10th of the match Oldboy is displayed if the first 10 rows do not match to Oldboy, and 10 lines match Oldboy later.
1,/alex/i	Line action on line 1th to match Alex
/oldboy/,+2i	2 rows to the following line to match Oldboy

Add or delete change

• A--append text to the specified line
• I--insert text before the specified line

在第二行后面添加内容sed ‘2a 106,dandan,CSO‘ person.txt

在第二行插入内容sed ‘2i 106,dandan,CSO‘ person.txt

在第二行后面添加两行内容sed ‘2a 106,dandan,CSO\n107,bingbing,CCO‘ person.txt

By deleting

• D--delete the specified row

删除所有行sed ‘d‘ person.txt

删除第二行sed ‘2d‘ person.txt

删除第二到五行sed ‘2,5d‘ person.txt

删除从第三行开始到最后sed ‘3,$d‘ person.txt

删除有关键字zhangyao的行sed ‘/zhangyao/d‘ person.txt

删除有oldboy的行到包含Alex的行（范围）sed ‘/oldboy/,/Alex/d‘ person.txt

Change

• C-replace old rows with new lines

将第二行替换成其他内容sed ‘2c 106,dandan,CSO‘ person.txt

• S--replace one string with another
• G--global substitution within a row
• -I--Modify file contents

sed -i ‘s/内容1/内容2/g‘ oldboy.logsed -i ‘s#内容1#内容2#g‘ oldboy.log定界符/或#，也可以是任意符号如:或|等，但当替换内容包含定界符时，需转义。默认sed软件是对模式空间(内存中的数据)操作，而-i选项会更改磁盘上的文件内容。定界符第一个和第二个之间的就是被替换的内容（可以使正则表达式），第二个和第三个之间的就是替换后的内容（必须是具体内容）。

指定行修改内容sed ‘3s#0#9#‘ person.txt

指定变量的内容去替换sed "s#$x#$y#g" test.txteval sed ‘s#$x#$y#g‘ test.txt

用sed命令重命名当前目录下包含_finished的jpg文件ls *.jpg |sed -r ‘s#(^.*)_finished.*#mv & \1.jpg#g‘ |bashls *.jpg    --列出所有的jpg文件sed -r  --使用正则表达式匹配(^.*)       --匹配任意字符串开头_finished.* --匹配包含_finished.，并任意字符串结尾mv &    -- &是显示前面匹配到的结果\1      -- 显示前面括号内匹配到的内容|bash   -- 以命令的形式执行替换后内容修改前stu_102999_1_finished.jpg 以命令的形式执行替换后内容mv stu_102999_1_finished.jpg stu_102999_1.jpg

Check

• P-Output specified content
  • But it will output 2 matches by default.
  • Use N to cancel default output

显示第二行内容sed -n ‘2p‘ person.txt

显示第二到第三行sed -n ‘2,3p‘ person.txt

显示所有行sed -n ‘p‘ person.txt

显示包含CTO的行sed -n ‘/CTO/p‘ person.txt

显示包含CTO的行到包含CFO的行（范围）sed -n ‘/CTO/,/CFO/p‘ person.txt

显示从第二行到包含CFO的行（范围）sed -n ‘2,/CFO/p‘ person.txt

04-linux Text Processing-sed