How can I convert tabs to spaces in every file of a directory?

Question

How can I convert tabs to spaces in every file of a directory (possibly recursively)?

Also, is there a way of setting the number of spaces per tab?

Answer 1

One can use vim for that:

find -type f \( -name '*.css' -o -name '*.html' -o -name '*.js' -o -name '*.php' \) -execdir vim -c retab -c wq {} \;

As Carpetsmoker stated, it will retab according to your vim settings. And modelines in the files, if any. Also, it will replace tabs not only at the beginning of the lines. Which is not what you generally want. E.g., you might have literals, containing tabs.