I repeat: "Note that there are only 14 lines following the 1st line, but the 1st line contains #data: 15 ;". The script you're using assumes that the 15 in the 1st line of your input file is correct and your output is wrong because that 15 should be 14 for the data in your input file.

If your input data is invalid, you will not get valid output. Or more commonly: GIGO (Garbage in; garbage out).

You can get the output you said want from that input with the following awk script (although I STRONGLY suggest that you not put a space in your filenames):

Code:

awk '
$1 == ">" {
        if(f) close(f)
        f="file " ++n
        next
}
{       print > f
}' UNZA2250.txt