ref: e1f02664d96e392a608d97c5bdd0c1c3c6a26c84
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;
}