Command line search and replace?

So I'm asking around for the best way to do search and replace in command line ... I have to copy files into another folder, but replace one word.

Tom pointed me towards using perl:

cp ./source/* ./destination/
cd ./destination/
perl -pi -e 's/foo/bar/' * 

Justin in contrast uses sed, and a loop:

cd ./source
for A in `ls`; do  echo sed 's/foo/bar/' $A > ./destination/$A; done;

Which brought me to finally look into the man pages for sed , the linux stream editor. Apparanetly the -i flag enables in-place editing there as well, and you could do something like tom did with sed:

cp ./source/* ./destination/
cd ./destination/
sed -i '' 's/foo/bar/' *

Initially, trying the -i flag, I got weird warnings like this:
sed: 1: "index.shtml": command i expects followed by text

This is due to the missing extension that you need to provide for the -i flag, in the case above I used '' to not create any backup files. If you provide '.bak' it will create backup files, i.e. index.shtml.bak before editing.

Happy search and replace!