ref: 424dea82a52d6d8ca3f16c34d1a5aa8d85a822b4
dir: /sys/src/ape/lib/ap/stdio/vsnprintf.c/
/*
* pANS stdio -- vsnprintf
*/
#define _C99_SNPRINTF_EXTENSION
#include "iolib.h"
int vsnprintf(char *buf, size_t nbuf, const char *fmt, va_list args){
int n;
FILE *f=_IO_sopenw();
if(f==NULL)
return 0;
setvbuf(f, buf, _IOFBF, nbuf);
n=vfprintf(f, fmt, args);
_IO_sclose(f);
return n;
}