Perl can handle both ends of CRLF and LF with an embedded :crlf PerlIO layer :
open(my $in, '<:crlf', $filename);
CRLF LF LF . CR - . , CR-, $/ "\r" ( CR LF).
( ), PerlIO::eol. :
open(my $in, '<:raw:eol(LF)', $filename);
CR, CRLF LF LF .
- $/ undef, slurp. /\r\n?|\n/. , , .