Re: Obtain hostnames from IP addresses
Quoting Conrado Badenas (Conrado.Badenas@uv.es):
> Does anyone know how to obtain hostnames (e.g., skywalker.termol.uv.es)
> from IP addresses (e.g., 147.156.6.236). I've written this program:
> [...]
> int l;
> char addr[]="147.156.6.236";
> struct hostent *ph;
>
> l=strlen(addr);ph=gethostbyaddr(addr,l,AF_INET);
You can do that sort of thing nicely in a language like Python
because it takes care of the structures for you. In C you've got
to do it all yourself. The value of l must be four, and addr
should be a pointer to an in_addr structure in network byte order.
> Is there any program (like a filter: input address in stdin, output name
> in stdout) that could do it? I've tried with nslookup but doesn't work
> (and it worked last month).
nslookup works here today. But I find python ideal for playing around
with these sorts of things. Elegant and easy.
Cheers,
--
Email: d.wright@open.ac.uk Tel: +44 1908 653 739 Fax: +44 1908 655 151
Snail: David Wright, Earth Science Dept., Milton Keynes, England, MK7 6AA
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official stationery. Views expressed here are either my own or plagiarised.
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