Greetings, fellow Monks.

I need help with yet another problem. I want to test the next line in a file to see if it is a certain type, or a new data set, or the end of file. Any idea how I can do this? Here's what I have so far:

open(IN, '<', $file) or die "Couldn't open $file for reading: $!\n\n";

my (@hdr, %stn, %seg);
my ($lname);
while (<IN>) {
        if (/^H/ ... /[<\[]/)    ## If it's a header line...
        {
                push(@hdr, $_);  ## ...add it to @hdr
                next;
        }

        next if (/reclin/i);
        ## If it's a DISCO header, ignore; continue to
        ## next iteration

        ## Not a header, so must be data....
        ( $lname =  substr($_,1,16) ) =~ s/\s+//g;
        ( my $s  =  substr($_,17,8) ) =~ s/\s+//g;
        ( my $x  =  substr($_,45,8) ) =~ s/\s+//g;
        ( my $y  =  substr($_,53,8) ) =~ s/\s+//g;
        ( my $z  =  substr($_,61,5) ) =~ s/\s+//g;

        $stn{$s} = [ $x, $y, $z ];
                   ## HoA:  Keys   =  Stn ID
                   ##       Value  =  Stn Coords

[download]

This builds an HoA of station numbers and coordinates. After this point, I want to check if the next line is a header line (/^H/ or /reclin/) or data from another seismic line. (The first header line always starts with 'H'.) If it is any of those, I want to "save" the current %stn hash and @hdr array to a hash as follows:

$seg{$lname} = { 'header'   => \@hdr,
                 'stations' => \%stn, };

[download]

(I think I've done the references correctly.) Then I need to clear the @hdr array and %stn hash to get ready for the next set of data. Data samples follow.

Data Sample, Case 1:

__DATA__
 80-101               412 54175659N114551423W 635314260187896 6756
 80-101               413 54175657N114551794W 635247260187870 6760
 80-101               414 54175655N114552165W 635180260187843 6775
 80-101               415 54175653N114552535W 635113360187817 6748
 80-101               416 54175650N114552905W 635046560187790 6721
H CLIENT      : *************
H PROSPECT    : *************
H CONTRACTOR  : CANJAY EXPLORATION          LINE NAME      : 80-103
H SURVEY CO.  : CANJAY EXP.                 UNIQUE ID      : *******

[download]

Data Sample, Case 2:

__DATA__
 80-101               412 54175659N114551423W 635314260187896 6756
 80-101               413 54175657N114551794W 635247260187870 6760
 80-101               414 54175655N114552165W 635180260187843 6775
 80-101               415 54175653N114552535W 635113360187817 6748
 80-101               416 54175650N114552905W 635046560187790 6721
 80-103               224 54160602N114433190W 648117760157647 6774
 80-103               225 54160602N114433561W 648050760157627 6769
 80-103               226 54160602N114433931W 647983760157606 6763
 80-103               227 54160602N114434302W 647916760157585 6758
 80-103               228 54160603N114434672W 647849760157564 6753

[download]

In reply to Matching next line in text file by YYCseismic

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