ngx_snprintf question

[Piotr Sikora]

Hi,

> I am getting unexpected results from ngx_snprintf in the following 
> statement:
>
>         ngx_snprintf((u_char *) buf, sizeof(buf), "%s\n",
> peer->peer_config->name.data);
>
> with peer->peer_config->name.data == "127.0.0.1:9000\0".
>
> I expect ngx_snprintf to yield buf == "127.0.0.1:9000\n\0", but
> instead it yields buf == "127.0.0.1:9000\n\bf\0" (I was not expecting
> that '\bf' character to be inserted there.)
>
> When I change ngx_snprintf to just snprintf, it works as expected.

ngx_snprintf isn't snprintf-equivalent (I was burned by this once myself), 
it doesn't add trailing '\0' and the "\bf\0" you're seeing is just the data 
that was in the buffer before.

You should either add "%Z" ('\0') to the format string or explicitly set 
'\0' yourself after ngx_snprintf() call.

Best regards,
Piotr Sikora < piotr.sikora at frickle.com >