Shell Programming and Scripting

I have a data of the form

0.0117843924 0. 0. 0. 0.
0.011036017 0. 0. 0. 0.
0.0103351669 0. 0. 0. 0.
4839.41211 0. 0. 0. 0.
4532.08203 0. 0. 0. 0.

I would like to insert a couple of blank lines before the 4839 line, every time it appears. The numbers in the first column follow the same pattern throughout the file, but the next 4 columns may change, so I can't just match the whole line.
Is there a neat way to do this, as I've had no luck with sed.

If I correctly understand you problem, one option would be:

Code:

awk '/^4839/{ for(i=1;i<=n;i++) printf RS; print; next }1' n=2 file

Change n to any number if you need more newlines.

perfect
Cheers