Hi all: I am new to Perl and having some problems... I have a txt file that contains data like this. 
A         B        C       D
1.0E-1  2.0E-2  3.1E-3  3.0E-9
1.0E-1  2.0E-2  3.2E-3  3.0E-9
1.0E-1  2.0E-2  3.3E-3  3.0E-9
1.0E-1  2.0E-2  3.4E-3  1.0E-1

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A B C D are separated by tab. I would like Perl to capture the C value right before D is larger than 1e-3 (capture Cn-1 when Dn > 1e-3; in this case that would be 3.3E-3), and my code right now looks like this: 
open (linedata, "/test.txt");
while  (<linedata>) {    
    ($A, $B, $C, $D) = split(/\t/, $_);
    print "$A, $B, $C, $D, \n"
    }
close (linedata);

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I don't really know how to process the "capturing Cn-1" part... Would someone please give me some insight? And if I add chomp to my code, the program whined about doesn't return a chomp value, which I don't know the reason. Appreciate to have some insight on chomp, too. Thank you guys!

In reply to Perl starter with questions about processing data from a txt file by willperl

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