find /home/site/htdocs -name "*.html" | xargs -n 1 perl -pi <<'PRG_END'
s|<!--#include virtual="/ssi/footer.txt"-->|<?php include(\$_SERVER['D
+OCUMENT_ROOT'].'/ssi/footer.txt'); ?>|g;
PRG_END

##</code><code>##

Can't open perl script "s|<!--#include": No such file or directory.
Use -S to search $PATH for it.
Can't open perl script "virtual=/ssi/edfooter.txt-->|<?php": No such file or directory.
Use -S to search $PATH for it.
Can't open perl script "include($_SERVER[DOCUMENT_ROOT]./ssi/edfooter.txt);": No such file or directory.
Use -S to search $PATH for it.
Can't open perl script "?>|g;": No such file or directory.
Use -S to search $PATH for it.