I suspect that what you really need is chomp, and that you don't need a regex at all. 
while (<$fh>) {
    chomp; # Line in $_ no longer has trailing \n

[download]
However, without seeing your code we can't confidently advise you either way.

In reply to Re: Replace new line with white space by wind
in thread Replace new line with white space by fattahsafa

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