Shell Programming and Scripting

All right, I thought it were literal num's Try this:

Code:

sed 's/^\([0-9]\{18\}\)  \([0-9]\)\./\1 0\2\./'

Thank you it works! can you please explain what you did? to know what to do when I want to do it for e.g. the 5th column

You're welcome. This sed command makes use of "group capturing" and does following:

Short version: It matches a pattern of 18 numbers (from the beginning of the line, this is represented by the "^" sign) followed by 2 whitespaces followed by one number followed by a literal dot.

If matched, then following happens:
Collect the first 18 numbers, from the beginning of the line and put them in a "variable" called "1".
Collect the next single number (followed by a dot) and put it a "variable" called "2".

The whole matched pattern gets replaced by \1 0\2\.
\1 means that the variable 1 is being "restored"
whitespace
(preceding) zero
\2 variable 2 is being "restored"
\. is a escaped dot, thus a literal dot.

I hope this is understandable.

---------- Post updated at 04:58 PM ---------- Previous update was at 04:53 PM ----------

To perform the conversion on the fifth column, you could try this:

Code:

sed 's/^\(.\{35\}\)  \([0-9]\)\./\1 0\2\./'
The red dot means any character/number/sign.

Thank you again I am grateful! u r an inspiration!