You probably really shouldn't do any detecting :)

You should be liberal in what you accept  s/[\r\n]+$//; and be strict in what you output  binmode  $fh, '...:crlf';

See also File::LocalizeNewlines and Encode::Newlines, PerlIO::eol and Devel::CheckOS

In reply to Re: Native newline encoding by Anonymous Monk
in thread Native newline encoding by salva

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