bash - 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

Simple replacement with sed is okay but not the best possible solution. If there are "extra" spaces between the tabs they will still be there after substitution, so the margins will be ragged. Tabs expanded in the middle of lines will also not work correctly. In bash, we can say instead

find . -name '*.java' ! -type d -exec bash -c 'expand -t 4 "$0" > /tmp/e && mv /tmp/e "$0"' {} ;

to apply expand to every Java file in the current directory tree. Remove / replace the -name argument if you're targeting some other file types. As one of the comments mentions, be very careful when removing -name or using a weak, wildcard. You can easily clobber repository and other hidden files without intent. This is why the original answer included this:

You should always make a backup copy of the tree before trying something like this in case something goes wrong.