print "\$adollarsign";
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Is surely in the docs but i cannot find it easely.. anyway look at quoted-interpolated-and-escaped-strings

PS perlop tell us Unary "\" creates a reference to whatever follows it. See perlreftut and perlref. Do not confuse this behavior with the behavior of backslash within a string, although both forms do convey the notion of protecting the next thing from interpolation.

PPS quotemeta can be also helpfull in your case. You can also use single quote or heredoc to prevent interpolation.

L*