Description: Stream editor - Stream editor, performs text filtering and formatted replacement output; sed has two built-in storage spaces: 1). The pattern space is cleared after executing the command. 2).Hold space will not be cleared by default

Command format: sed [options] -f scriptfile files #Support multiple files sed [options] '[address range|pattern range] s#{replaced string}#{replaced string}#{replacement flag}' [input file]

Multiple expressions: sed 'expression' | sed 'expression' #Equivalent to the following sed statement sed 'expression; expression'

-i: Directly modify the content of the file from which the data is read, rather than output by Screen. (Directly add or backup to the source file)

-r: supports extended expressions. There is no need to use \() to escape () in sed.

-f <script file> or --file=<script file>: #Process the input text file with the script file specified in the option

-n or --quiet or --silent: #Cancel the default output, only display the results after script processing, and output to the Screen;

-e <script> or --expression=<script>: #Use the script specified in the option to process the input text file and execute multiple sed commands.

Add operation

Delete operation

Change operation

Check operation

File save and read

Line number and reverse acquisition

Determine which character to start processing, 1-512 numeric mark

i ignore case for replace/match/find

g means full replacement within the line

p means print line, often used with -n

Case conversion: \l \L \u \U i.e. lower / upper

y: Convert the matched string to uppercase and lowercase, regardless of whether g is added or not.

e execute command flag, execute any content in the pattern space as a bash command (note the spaces)

Regular matching uses: \1 substring matching tag & matched string tag

w means to write lines to a file. x means swapping the text in the template block with the text in the buffer.

Note: sed does not have \d \w metacharacters representing numbers and letters, only the following metacharacters

^ matches the beginning of a line, such as: /^sed/ matches all lines beginning with sed. $ matches the end of the line, such as: /sed$/ matches all lines ending with sed. . Matches any character that is not a newline character, such as: /s.d/ matches s followed by any character, and finally d. * Matches 0 or more characters, such as: /*sed/ Matches all lines whose template is one or more spaces followed by sed. [] matches characters within a specified range, such as /[ss]ed/ matches sed and Sed. [^] matches a character that is not within the specified range, such as: /[^A-RT-Z]ed/ matches a line starting with a letter that does not contain A-R and T-Z, followed by ed. \(..\) matches substrings and saves the matched characters, such as s/\(love\)able/\1rs, loveable is replaced by lovers. & saves the search characters to replace other characters, such as s/love/**&**/, love becomes **love**. \< matches the beginning of a word, such as:/\<love/ matches lines that contain words starting with love. \> Matches the end of a word, such as /love\>/ Matches lines containing words ending with love. x\{m\} repeats the character x, m times, such as: /0\{5\}/ matches lines containing 5 zeros. x\{m,\} repeats the character x at least m times, such as: /0\{5,\}/ matches lines with at least 5 zeros. x\{m,n\} repeats the character

Delete command d

Replace command s

Read file command r

Write file command w

Append command

Modify command c

Get the next command n

Negate the option!

l (lowercase l) prints and displays special characters (end of line and tab mark)

Special symbols {} Commands enclosed in {} are executed in order, and previous commands will affect subsequent commands.

sed scripting