new sed commands (#2104)

* delete and insert text with sed

* regex ranges and replacements

---------

Co-authored-by: joessi <[email protected]>

sed.md

@@ -6,9 +6,9 @@ intro: |
   Here's some hints on using sed.
 ---
 
-## In place replacements
+### Replacements
 
-### In-place replacement (GNU)
+#### In-place replacement (GNU)
 
 ```bash
 sed -i -e 's/foo/bar/' example.md
@@ -22,9 +22,26 @@ In GNU sed: use `-i` without arg.
 sed -i '' -e 's/foo/bar/' example.md
 ```
 
- In OSX, `-i ''` is required.
+In OSX, `-i ''` is required.
+
+#### In-place Multiple replacements
+
+```bash
+sed -i 's/match1/replace1/g; s/match2/replace2/g' \
+
+```
+
+replace different matchs with different values
+
+```bash
+sed -i 's/\(MATCH1\|MATCH2\)/VALUE/g' \
+
+```
+
+replace multiple matchs with the same value
 
 ## File regions
+
 {:.-three-column}
 
 ### Print until a certain line is met
@@ -54,3 +71,73 @@ sed -n '/regex/!p'
 ```
 
 Print everything except lines matching regex. Useful for printing files with comments.
+
+#### Printing REGEX ranges
+
+```bash
+sed -n -e '/^START$/,/^END$/p'
+```
+
+suppress output and print REGEX range
+include (^START$,^END$) lines.
+
+**OR** without "-n" (same result)
+
+```bash
+sed -e '/^START$/,/^END$/p;d'
+```
+
+print REGEX range and delete other
+output, the [;] character means run another
+expression on the input file which is 'd' stands for delete .
+
+### Append a text after a specific line number
+
+```bash
+sed -e "1a ## HEADING 02:" README.md
+```
+
+this appends "## HEADING 02:" after the first line in the file README.md
+and print the result to stdout replace -e with -i to write the file .
+
+### Insert text before a specific line number
+
+```bash
+sed -e "1i # HEADING 01:" README.md
+```
+
+the same as appending but before the first line.
+
+### Deleting text
+
+#### With line number
+
+```bash
+sed -e "1,5d" README.md
+```
+
+delete a RANGE (i.e. including lines 1 to 5)
+
+```bash
+sed -e '1,5!d' README.md
+```
+
+delete everything (i.e. excluding lines 1 to 5)
+it is better to quote sed expressions with single quotes
+especially when there is a [!] character.
+
+#### With REGEX matching
+
+```bash
+sed -e "/REGEX/Id" README.md
+```
+
+delete lines with /REGEX/ matched
+/I is for insensitive search
+
+```bash
+sed -e '/REGEX/Ip;d' README.md
+```
+
+this invert the previous sed command
+delete everything (excluding lines with REGEX)