Almost everyone who uses Unix or Linux agrees that vim (or vi for the super-hardcore folks) is the editor of choice. Pico and nano are for sissies. Emacs, you say? I believe the old joke goes "Emacs is a great operating system but lacks a good editor." I give you a +1 if you get the joke. Kidding aside, let me get to the point of the post.
Vim, or vi improved for the unfamiliar, allows you to edit a file without getting your hands dirty via the -c option. This option allows you to pass a vim command directly from the *nix command line. With this nifty trick, it's easy to iterate through a list of files and perform the same edit on all of them in no time flat. Let's say that you have ten files all containing a host named foo.net which needs to be changed to bar.com. if all of the files are sitting in one directory and for simplicity's sake, named 1-10.txt you could do something like this:
for file2edit in *.txt; do vim -c "%s/foo.net/bar.com/g" -c "wq" $file2edit; doneThe command will loop over all files ending in *.txt and do a simple string substitution followed by a save and quit in vim. Of course, depending on your situation you will like need to tweak the for loop or vim command line a bit, but this should give you an idea of the potential time savings. I'll try to post a similar example using sed soon.