>Usage
sed (Stream Editor) is a text transformation wizard that modifies your text on the fly. Think of it as a mini production line where your text flows through, and sed applies changes as the text passes by – whether it’s replacing words, deleting lines, or inserting new content. It’s your go-to tool for automated text surgery!
>Synopsis
>Options
-i
-i (in-place): Makes changes directly to files, like editing a document with a permanent marker.
Example 1:
-zsh
> echo "old text" > file.txt
> sed -i 's/old/new/' file.txt
> cat file.txt
new text
-e
-e (expression): Allows multiple transformations in one go.
Example 2:
-zsh
> echo "The old gray dog" > file.txt
> sed -e 's/old/young/' -e 's/gray/brown/' file.txt
The young brown dog
-n
-n (quiet): Only shows what you specifically ask to see, like a stealth mode for text processing.
Example 3:
-zsh
> echo -e "Line 1\nLine 2\nLine 3" > file.txt
> sed -n '2p' file.txt
Line 2
p
p (print): Prints specific lines, much like a spotlight operator highlighting exactly what you want.
Example 4:
-zsh
> echo -e "One\nTwo\nThree" > numbers.txt
> sed -n '/Two/p' numbers.txt
Two
d
d (delete): Removes specified lines, imagine it like a paper shredder for specific parts of your text.
Example 5:
-zsh
> echo -e "Keep\nDelete\nKeep" > file.txt
> sed '/Delete/d' file.txt
Keep
Keep
s/p/r
s/pattern/replacement/ (substitute): Replaces text patterns, like find-and-replace in a word processor.
Example 6:
-zsh
> echo "The cat sleeps" > file.txt
> sed 's/cat/dog/' file.txt
The dog sleeps
a\
a\ (append): Adds new lines after matches.
Example 7:
-zsh
> echo "Original line" > file.txt
> sed '/Original/a\
New line below' file.txt
Original line
New line below
i\
i\ (insert): Adds new lines before matches.
Example 8:
-zsh
> echo "Original line" > file.txt
> sed '/Original/i\New line above' file.txt
New line above
Original line