http://www.perlmonks.org?node_id=142643


     perl -MCPAN -e 'install jmcnamara & _ x ord $ ;'  | tail -1

--
John.

Replies are listed 'Best First'.
Re: Ghost in the machine.
by jmcnamara (Monsignor) on Feb 01, 2002 at 14:46 UTC

    For those who don't have CPAN configured, here is the output: 
    
    Don't be silly, you can't install John McNamara ;-)

    [download]

    --
    John.

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Re: Ghost in the machine.
by BazB (Priest) on Feb 02, 2002 at 14:58 UTC

    Could you explain how this is possible?

    I've grepped through CPAN/*.pm, but I've failed to find any relevant code.

[reply]
[d/l]

      This is more artifice than obfuscation.

      The "& _ x ord $ ;" code is used to convert my lowercase PerlMonks ID jmcnamara to my uppercase CPAN directory JMCNAMARA. I could have used uc but I thought that I should put in a little effort. ;-) 

          # The following are equivalent

    perl -MCPAN -e 'install jmcnamara & _ x ord $ ;'

    perl -MCPAN -e 'install "jmcnamara" & ( "_" x ord($;) )'

    perl -MCPAN -e 'install "jmcnamara" & ( "_" x 28 )'

    # With bitwise string "&" the longer string is truncated
    # to the length of the shorter string. Therefore:

    perl -MCPAN -e 'install "jmcnamara" & ( "_" x 9 )'

    perl -MCPAN -e 'install "jmcnamara" & "_________"'

    perl -MCPAN -e 'install JMCNAMARA'

      [download]

      Running this will cause CPAN to generate an error because you are trying to install a directory instead of module (or bundle). This helpfully translates my PerlMonks name into my real name. Here is the output as seen through tail -l.     Don't be silly, you can't install John McNamara ;-)

      This error message is buried in CPAN.pm.

      --
      John.

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