Question

I’ve a file and I want to make the following changes in it:

Replace n consecutive spaces by n-1 spaces.

Example:

Input:

a b  c   e
fg j    ij k

Output:

ab c  e
fgj   ijk

How do I do it?

Answer 1

You can do it in sed as:

sed  -r -i 's/ ( *)/\1/g' in

The regex used / ( *)/ searches for a space followed by zero or more spaces. It remembers the zero or more spaces part and replaces the entire spaces by the remembered part.