Delete specific line number(s) from a text file using sed?

Question

I want to delete one or more specific line numbers from a file. How would I do this using sed?

Answer 1

If you want to delete lines 5 through 10 and 12:

sed -e '5,10d;12d' file

This will print the results to the screen. If you want to save the results to the same file:

sed -i.bak -e '5,10d;12d' file

This will back the file up to file.bak, and delete the given lines.

Answer 2

$ cat foo
1
2
3
4
5
$ sed -e '2d;4d' foo
1
3
5
$ 

Answer 3

and awk as well

awk 'NR!~/^(5|10|25)$/' file