# cat s.c
main(int ac, char **av) { execv("/home/thayer/foo.pl", av); }
# gcc s.c -o s
# chown root s; chmod a+rx,u+s s ; ls -l s
-rwsrwxr-x   1 root     users       11394 Dec 15 11:43 s
# cat foo.pl
#!/usr/local/bin/perl -T
print "$< $>\n";
# ls -l foo.pl
-r-xr-xr-x   1 thayer   users          43 Dec 15 11:42 foo.pl
$ ./s
3068 0