A little collection of sed tips.
The basic one, substitution
You already know this one:
sed -i 's/old text/new text/g' file.txt
Deleting all lines containing an specific text
sed -i -e '/this line will disapear/d' file.txt
Deleting blank lines
sed -i -e '/^$/d' file.txt
Filtering text between delimiters
All matching text into the first defined group “()” will be printed:
curl -s -L http://www.terra.com.br | sed -n -e 's#.*\(http://.*\.\(js\|css\)\).*#\1#p'
Printing only from a given line number to another
Prints from line 20 to line 30:
sed -n 20,30p file.txt
More tips can be found here.
Do you know some trick that is worth sharing? Please post it as a comment!