Hi,
In response to XS on 64-bit: Warning from sv_vsetpvf call almut posted some code that led me to the following Inline::C script:

use warnings;

use Inline C => <<'EOC';

void vatest__(char* format, va_list* args) {
    char buf[1024];
    vsprintf(buf, format, *args);
    errno = 0;  // "Success"
    perror(buf);
}


void vatest_(char* format, va_list* args) {
    
    vatest__(format, args);
}


void vatest(char* format, ...) {
    va_list args;
    va_start (args, format);
    vatest_(format, &args);
    va_end (args);
}

SV * foo () {
    char* msg0 = "vatest";
    char* msg1 = "foo";
    char* msg2 = "bar";
    double d = 12.345;
    unsigned long l = 1234567890;
    vatest("%s %s", msg0, msg1);
    vatest("%s %s %s %u %f", msg0, msg1, msg2, l, d);
    return newSViv(0);
}

EOC

foo();
[download]

which outputs (on Win32):

vatest foo: No error
vatest foo bar 1234567890 12.345000: No error
[download]

which is correct and as expected.

But then I got to wondering whether vatest() could be called directly from perl - ie, instead of having the perl section of the above script do foo(); have it do something like vatest('%s %s', 'foo', 'bar'); which would output foo bar: No error.
But, of course, that doesn't work - and I'm unable to find a way of making it work.

So, is there a way of accessing the XSub vatest() directly from perl (with either XS or Inline::C) ? I'm pretty sure there isn't ... but I'm so often wrong. Faik, there could well be some clever typemapping (or other technique) that makes it possible.

Cheers,
Rob

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.