It's difficult to know what the OP needs, even after the OP said, "...I read text from file into string...", since the following reads text from a file into a string, but chomp--in this case--will not remove newlines from $record:

use strict;
use warnings;

local $/ = \1024;

open my $fh, '<', 'records.txt' or die $!;

while ( my $record = <$fh> ) {

    # process 1024-byte, fixed-length, newline-containing record
}

close $fh;
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