Both solutions remove the blank lines; however, Joeyg's example removes all blank lines. I just need to match the dhcp host blocks then reove blank lines.

Franklin52's example removes all the blank lines; but, the example first needs to read in the file, copy the output to a new file, then move the new file back to the original.

Any SED gurus have an interactive example? Meaning make the changes take place without piping the output to a new file.

I can copy the host blocks to holding buffer and delete; but, I can not copy them back correctly from the holding buffer. Here is what I got so far:


sed -e '/host/,/}/{h; d;}' -e '/$/{G;}' dhcpd.conf



The above command appends the "}" to the end of the file, not the whole host block. Also, it is not doing it interactively. I tried adding the -i option. It didn't work.