I need some advice with working with a fixed length file that uses two different formats, the format switches every other line in the file. Here is an example of the file contents 

03002068454210482                            000000004204.572011-04-14
+ 19:53:41I
NTERNET  C  750467375                   ^M
0214833                                                               
+          
                    G02042954           ^M
03002068703214833                            000000002558.662011-04-15
+ 08:17:19I
NTERNET  C  761212737                   ^M
0211561                                                               
+          
                    05601207284         ^M
03002068802911561                            000000001463.702011-04-15
+ 08:40:52I
NTERNET  C  719807216                   ^M
029911                                                                
+          
                    00100275296         ^M

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The lines that have "03" as the first two characters match the following patterns: 02:10:33:15:19:10:3:18:6:4 While the other lines match this pattern: 02:98:11:9 Is using read and unpack the best way to approach this? The way that I am currently working with this I don't think this will work here becuase it loads in a file that has the pattern that matches the currently loaded file, in all I am working with four files and this is the only one that differs like this. 
#!/usr/bin/perl
use strict;
use warnigns;

my $filename = 'fixedfile.txt';
my $datname = $filename;
$datname =~ s/\.txt//g;
my $fc = 0;
my @fla;
my @fna;
open my $dat, '<', "$datname.dat";
while (<$dat>) {
    chomp;
    my @fields = split(/\|/);
    foreach(@fields) {
        my ($field, $length) = split(/\:/, $_);
        if ( $length < 1 ) {
            $length = 1;
        }
        $fla[$fc] = $length;
        $fna[$fc] = $field;
        $fc++;
    }
}
close $dat;
open my $fixedfile, '<', "$filename";
while (<$fixedfile>) {
    chomp;
    s/\r|\n//g;
    s/^M//g;
    s/^\s*//;
    s/\s*$//;
    my $line = $_;
    my $dc = 0;
    my $start = 0;
    foreach (@fna) {
        my $garbage = substr($line,$start,$fla[$dc]);
        $garbage =~ s/\'//g;
        $garbage =~ s/\"//g;
        $garbage =~ s/\\//g;
        $garbage =~ s/\(//g;
        $garbage =~ s/\)//g;
        $garbage =~ s/^\s*//;
        $garbage =~ s/\s*$//;
        $start = $start + $fla[$dc];
        $dc++;
    }
    close $fixedfile;
}

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In reply to Working with fixed length files by vendion

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