C strings vs Perl strings

• Perl strings ne C strings

    $a = "foo\000bar";	# embedded null!
    length($a) == 7;	# no terminal null
  

• Unwise to use strlen() on PVs
• SvPV macro extracts pointer and length

    char *p; SV *s; STRLEN len;
    p = SvPV(s, len);