It's generally considered "bad form" to call sed or awk from perl, as Perl for the most part supercedes both of them. For instance, your example could be expressed as: 
$haha =~ s/tyre/tire/g;

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Also, as part of the standard perl distribution, there'a a2p and s2p, the awk-to-perl and sed-to-perl translators, respectively.

Welcome to perl,
thor

Feel the white light, the light within
Be your own disciple, fan the sparks of will
With all of us waiting, your kingdom will come

In reply to Re: sed in perl by thor
in thread sed in perl by Anonymous Monk

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