Search and replace in multiple files.

find app/code/local/Flux/Catalog/ -name "*.php" -print | xargs sed -i 's/Mage_Catalog/Flux_Catalog/g'


perl -w -i -p -e "s/search_text/replace_text/g" filename


perl -w -i -p -e "s/search_text/replace_text/g" *.php


find /www_root -name "*.php"|xargs perl -w -i -p -e "s/Perl is good/perl is great/g"