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

The use of expand as suggested in other answers seems the most logical approach for this task alone.

That said, it can also be done with Bash and Awk in case you may want to do some other modifications along with it.

If using Bash 4.0 or greater, the shopt builtin globstar can be used to search recursively with **.

With GNU Awk version 4.1 or greater, sed like "inplace" file modifications can be made:

shopt -s globstar
gawk -i inplace '{gsub("\t","    ")}1' **/*.ext

In case you want to set the number of spaces per tab:

gawk -i inplace -v n=4 'BEGIN{for(i=1;i<=n;i++) c=c" "}{gsub("\t",c)}1' **/*.ext