[prog] using sed on multiple files

[jennyw]

I'd guess that Finne's suggestion about -i would work ... I know I use it 
that way with Perl or Ruby (sorry, I don't know sed very well at all). The 
only additional suggestion I could make is that maybe you'd have more 
flexibility using xargs?

To replace a string in a bunch of files, I normally use the in-place-edit 
option (which is -i in both Perl and Ruby as well as, apparently, sed) along 
with find and xargs. For example, to substitute "find" with "replace" in all 
files ending in .txt, I'd do this (using Ruby):

find . |grep -i "\.txt$" | xargs ruby -p -i -e 'gsub(/find/i, "replace")'

or, with Perl:

find . |grep -i "\.txt$" | xargs perl -p -i -e "s/find/replace/gi"

Jen