Resolving IP addresses in vim
A friend on IRC said: "I wish vim had a command to resolve all the IP addresses in a block of text".
But it does:
:<block>!perl -MSocket -pe 's/(\d+\.\d+\.\d+\.\d+)/gethostbyaddr(inet_aton($1), AF_INET)/ge'
If you use it often, put the perl command in a one-liner script and call it an editor macro. It works on other editors, too, and even without an editor at all. And it can be scripted!
We live with the power of Unix every day, so much that we risk forgetting how awesome it is.