[libvirt] [PATCH] virConnectGetHostname: return a fully qualified hostname

[Daniel P. Berrange]

On Wed, Dec 10, 2008 at 07:33:17PM -0800, David Lutterkort wrote:
> The attached patch makes virConnectGetHostname try a little harder to get a
> FQDN on systems where gethostname only returns a short name without a
> domain (which is pretty useless). The behavior is equivalent to 'hostname
> --fqdn'.
> 
> > From 2ae57d0c8c68c453b3f9715fcc9f83af0ebe84a0 Mon Sep 17 00:00:00 2001
> From: David Lutterkort <lutter at redhat.com>
> Date: Wed, 10 Dec 2008 18:34:39 -0800
> Subject: [PATCH] virConnectGetHostname: return a fully qualified hostname
> 
> Instead of doing the equivalent of 'hostname', do 'hostname --fqdn',
> i.e. try to qualify the local host name by an additional call to
> gethostbyname(3)
> +
> +char *virGetHostname(void)
> +{
> +    int r;
> +    char hostname[HOST_NAME_MAX+1], *str;
> +    struct hostent *he;
> +
> +    r = gethostname (hostname, HOST_NAME_MAX+1);
> +    if (r == -1)
> +        return NULL;
> +    if (!(he = gethostbyname(hostname)))
> +        return NULL;

Actually, gethostbyname should never be used in any modern code as it is
not thread safe. Instead use getaddrinfo() and  the AI_CANONNAME flag

Daniel
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