use strict;
use warnings;

# Initialise file names and open files, one
# for reading, two for writing.
#
my $inputFile  = q{spw579580.inp};
my $headerFile = q{spw579580.hdrs};
my $detailFile = q{spw579580.dets};

open my $inputFH, q{<}, $inputFile
   or die qq{open: $inputFile: $!\n};
open my $headerFH, q{>}, $headerFile
   or die qq{open: $headerFile: $!\n};
open my $detailFH, q{>}, $detailFile
   or die qq{open: $detailFile: $!\n};

# In a code block localise $/, the input record
# separator, to your end of record string.
#
{
    local $/ = qq{EOE\n};

    # Read each record in a while loop. Strip the
    # start and end record sentinels off.
    #
    while (defined(my $record = <$inputFH>))
    {
        $record =~ s{\A\^L\n}{};
        $record =~ s{EOE\n\z}{};

        # We now have the record in a scalar
        # variable $record ready for processing.
        #

        # FURTHER PROCESSING GOES HERE ...
    }
}

# Close open filehandles.
#
close $inputFH
   or die qq{close: $inputFile: $!\n};
close $headerFH
   or die qq{close: $headerFile: $!\n};
close $detailFH
   or die qq{close: $detailFile: $!\n};