Hi,

I have a number of large (500Mb) txt files in the following format:

  8.05475136E+05  9.69428147E+05  1 14  2968.00   3419.00     59.00   59 3.4028235E+38 2 w99-100
  8.05464719E+05  9.69435064E+05  1 14  2968.03   3418.50     60.00   60 3.4028235E+38 2 w99-100
  8.05454301E+05  9.69441981E+05  1 14  2968.05   3418.00     61.00   61 3.4028235E+38 2 w99-100
  8.05443884E+05  9.69448898E+05  1 14  2968.08   3417.50     62.00   62 3.4028235E+38 2 w99-100
  8.05433466E+05  9.69455815E+05  1 14  2968.11   3417.00     63.00   63 3.4028235E+38 2 w99-100
  8.05423048E+05  9.69462733E+05  1 14  2968.14   3416.50     64.00   64 3.4028235E+38 2 w99-100
  8.05412631E+05  9.69469650E+05  1 14  2968.16   3416.00     65.00   65 3.4028235E+38 2 w99-100
  8.05402213E+05  9.69476567E+05  1 14  2968.19   3415.50     66.00   66 3.4028235E+38 2 w99-100
  8.05391795E+05  9.69483484E+05  1 14  2968.22   3415.00     67.00   67 3.4028235E+38 2 w99-100
  8.05381378E+05  9.69490401E+05  1 14  2968.24   3414.50     68.00   68 3.4028235E+38 2 w99-100
  8.05370960E+05  9.69497318E+05  1 14  2968.27   3414.00     69.00   69 3.4028235E+38 2 w99-100

If losing the blank space formatting is ok with you, then one option could be:

$
$ awk '{printf("%.3f %.3f %s %s %s %s %s %s %s %s %s\n",$1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11)}' data.txt
805475.136 969428.147 1 14 2968.00 3419.00 59.00 59 3.4028235E+38 2 w99-100
805464.719 969435.064 1 14 2968.03 3418.50 60.00 60 3.4028235E+38 2 w99-100
805454.301 969441.981 1 14 2968.05 3418.00 61.00 61 3.4028235E+38 2 w99-100
805443.884 969448.898 1 14 2968.08 3417.50 62.00 62 3.4028235E+38 2 w99-100
805433.466 969455.815 1 14 2968.11 3417.00 63.00 63 3.4028235E+38 2 w99-100
805423.048 969462.733 1 14 2968.14 3416.50 64.00 64 3.4028235E+38 2 w99-100
805412.631 969469.650 1 14 2968.16 3416.00 65.00 65 3.4028235E+38 2 w99-100
805402.213 969476.567 1 14 2968.19 3415.50 66.00 66 3.4028235E+38 2 w99-100
805391.795 969483.484 1 14 2968.22 3415.00 67.00 67 3.4028235E+38 2 w99-100
805381.378 969490.401 1 14 2968.24 3414.50 68.00 68 3.4028235E+38 2 w99-100
805370.960 969497.318 1 14 2968.27 3414.00 69.00 69 3.4028235E+38 2 w99-100
$
$

Cheers @tyler_durden for the quick response.
I've reviewed what I've been requested to do and figured that I really only need columns $1, $2, and $5 which are all the same length so losing the blank space formatting is okay at this point.

However keeping the space formatting is essential for most requests.

If anyone knows how this can be achieved I would be interested to hear it.

Cheers,
Barry

Try this:

awk -F" |:" '
{$3=sprintf("%.3f", $3)}
{$5=sprintf("%.3f", $5)}
1' file

That's perfect @Franklin52
Good job

Thanks very much @Franklin52 and @tyler_durden!!!
Barry