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

Use backslash-escaped sed.

On linux:

• Replace all tabs with 1 hyphen inplace, in all *.txt files:

  sed -i $'s/\t/-/g' *.txt
  

• Replace all tabs with 1 space inplace, in all *.txt files:

  sed -i $'s/\t/ /g' *.txt
  

• Replace all tabs with 4 spaces inplace, in all *.txt files:

  sed -i $'s/\t/    /g' *.txt
  

On a mac:

• Replace all tabs with 4 spaces inplace, in all *.txt files:

  sed -i '' $'s/\t/    /g' *.txt