Question

I have a file like this: (is much longer though)

     1  5.60
     2  6.20
     3  6.58
     4  7.32
     5  8.10
     6  7.70

how can I use sed to make the list like this:

     1: 5.60
     2: 6.20
     3: 6.58
     4: 7.32
     5: 8.10
     6: 7.70

Thanks

Answer 1

sed 's/\(\S\)\s/\1:/' your_file

This should work with multiple digit numbers as well, as long as there is always at least one space between the two numbers on each line.