ref: 12634d25a1f63f5422cd6dabb14a3d0eb2b1ff22
dir: /sys/src/libc/fmt/vseprint.c/
#include <u.h>
#include <libc.h>
char*
vseprint(char *buf, char *e, char *fmt, va_list args)
{
Fmt f;
if(e <= buf)
return nil;
f.runes = 0;
f.start = buf;
f.to = buf;
f.stop = e - 1;
f.flush = nil;
f.farg = nil;
f.nfmt = 0;
f.args = args;
dofmt(&f, fmt);
*(char*)f.to = '\0';
return f.to;
}