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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();
which outputs (on Win32):
vatest foo: No error vatest foo bar 1234567890 12.345000: No error
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.


In reply to XS/Inline::C and ellipsis syntax by syphilis

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