What is this doing ??

[T.S. Ravi Shankar]

Hi all :

I see these lines at the very beginning lines of a perl program.  Could
anyone explain what this is doing ??

eval '(exit $?0)' && eval 'exec perl $PERL_OPTIONS $0 ${1+"$@"}'
    & eval 'exec perl $PERL_OPTIONS $0 $argv:q'
    if 0;

In what way "eval" help here in traping the errors ??   Where does
$PERL_OPTIONS get value ??


Thank you very much,
Ravi