gethostbyname和getservbyname这类调用是怎么实现的

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Subject: gethostbyname和getservbyname这类调用是怎么实现的
Author: neaoy    Posted: 2001-01-08 10:42    Length: 197 byte(s)

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这类系统调用在网络连接前就可以背调用，那他们从那里得到相应的并不是本机的信息呢

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Subject: Re: gethostbyname和getservbyname这类调用是怎么实现的
Author: astonia    Posted: 2001-01-08 23:10    Length: 63 byte(s)

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都是调的本地数据库：/etc/host, /etc/service

 

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Subject: Re: gethostbyname和getservbyname这类调用是怎么实现的
Author: r00t    Posted: 2001-01-08 23:36    Length: 231 byte(s)

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gethostbyname是网络数据库函数，其作用就是去internet的DNS主机去
查询相应主机的情况，这是通过分布在全球各个地方的DNS服务器来实现的。

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Subject: Re: gethostbyname和getservbyname这类调用是怎么实现的
Author: neaoy    Posted: 2001-01-09 10:59    Length: 233 byte(s)

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综合两位大虾的意见：是不是建立连接前调用本地数据库，建立连接以后被调用时先找本地数据库，找不着再到各个DNS主机去查？

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Subject: Re: gethostbyname和getservbyname这类调用是怎么实现的
Author: astonia    Posted: 2001-01-09 17:12    Length: 156 byte(s)

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look up in the local database(/etc/hosts) first, then the name server(dns, nis or something), whatever your machine is networked or not.