Rob, I am glad that other Monks jumped in on this.

I agree with this: I'm not convinced that the need to pass NULL pointers from perl to C functions is all that common.

As I mentioned in previous posts, the OP is confronted with some poorly written C code that he can't change. This NULL pointer idea arises from an I/F that says: "if you give a pointer to memory, I will use that memory for output, assuming without question that you have given me enough memory for my yet to be generated output. If you don't give me such a pointer, I will give you a pointer to my non-thread-safe non-recursion-safe static memory." This is a bullshit I/F. But the OP can't change that.

NULL as the 2nd param is a weird situation. If there could be one arg and an optional second arg, then normally this would be implemented with a variable number of args - you don't put NULL, for that second arg - it is simply not there at all for the caller. This of course requires different C code than what the OP is dealing with. printf() for example uses a variable number of arguments.

I did have fun with Inline::C and found it to be "easy to use" for all the "heavy lifting" that is does.

In reply to Re^9: Inline::C and NULL pointers by Marshall
in thread Inline::C and NULL pointers by markong

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.