ref: a5488ad1e64e34f8a2f2e604ca5bcd2a0b750f67
dir: /sys/src/cmd/upas/fs/readdir.c/
#include <u.h>
#include <libc.h>
void
main(void)
{
Dir d;
int fd, n;
fd = open("/mail/fs", OREAD);
while((n = dirread(fd, &d, sizeof(d))) > 0){
print("%s\n", d.name);
}
print("n = %d\n", n);
}