lwres_gethostent.docbook

非常好的dns解析软件

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<refentry>

  <refentryinfo>
    <date>Jun 30, 2000</date>
  </refentryinfo>

  <refmeta>
    <refentrytitle>lwres_gethostent</refentrytitle>
    <manvolnum>3</manvolnum>
    <refmiscinfo>BIND9</refmiscinfo>
  </refmeta>

  <docinfo>
    <copyright>
      <year>2004</year>
      <year>2005</year>
      <year>2007</year>
      <holder>Internet Systems Consortium, Inc. ("ISC")</holder>
    </copyright>
    <copyright>
      <year>2001</year>
      <holder>Internet Software Consortium.</holder>
    </copyright>
  </docinfo>

  <refnamediv>
    <refname>lwres_gethostbyname</refname>
    <refname>lwres_gethostbyname2</refname>
    <refname>lwres_gethostbyaddr</refname>
    <refname>lwres_gethostent</refname>
    <refname>lwres_sethostent</refname>
    <refname>lwres_endhostent</refname>
    <refname>lwres_gethostbyname_r</refname>
    <refname>lwres_gethostbyaddr_r</refname>
    <refname>lwres_gethostent_r</refname>
    <refname>lwres_sethostent_r</refname>
    <refname>lwres_endhostent_r</refname>
    <refpurpose>lightweight resolver get network host entry</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
<funcsynopsisinfo>#include &lt;lwres/netdb.h&gt;</funcsynopsisinfo>
<funcprototype>
        <funcdef>
struct hostent *
<function>lwres_gethostbyname</function></funcdef>
        <paramdef>const char *<parameter>name</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent *
<function>lwres_gethostbyname2</function></funcdef>
        <paramdef>const char *<parameter>name</parameter></paramdef>
        <paramdef>int <parameter>af</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent *
<function>lwres_gethostbyaddr</function></funcdef>
        <paramdef>const char *<parameter>addr</parameter></paramdef>
        <paramdef>int <parameter>len</parameter></paramdef>
        <paramdef>int <parameter>type</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent *
<function>lwres_gethostent</function></funcdef>
        <paramdef>void</paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
void
<function>lwres_sethostent</function></funcdef>
        <paramdef>int <parameter>stayopen</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
void
<function>lwres_endhostent</function></funcdef>
        <paramdef>void</paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent *
<function>lwres_gethostbyname_r</function></funcdef>
        <paramdef>const char *<parameter>name</parameter></paramdef>
        <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>
        <paramdef>char *<parameter>buf</parameter></paramdef>
        <paramdef>int <parameter>buflen</parameter></paramdef>
        <paramdef>int *<parameter>error</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent  *
<function>lwres_gethostbyaddr_r</function></funcdef>
        <paramdef>const char *<parameter>addr</parameter></paramdef>
        <paramdef>int <parameter>len</parameter></paramdef>
        <paramdef>int <parameter>type</parameter></paramdef>
        <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>
        <paramdef>char *<parameter>buf</parameter></paramdef>
        <paramdef>int <parameter>buflen</parameter></paramdef>
        <paramdef>int *<parameter>error</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
struct hostent  *
<function>lwres_gethostent_r</function></funcdef>
        <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>
        <paramdef>char *<parameter>buf</parameter></paramdef>
        <paramdef>int <parameter>buflen</parameter></paramdef>
        <paramdef>int *<parameter>error</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
void
<function>lwres_sethostent_r</function></funcdef>
        <paramdef>int <parameter>stayopen</parameter></paramdef>
        </funcprototype>
<funcprototype>
        <funcdef>
void
<function>lwres_endhostent_r</function></funcdef>
        <paramdef>void</paramdef>
      </funcprototype>
</funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>DESCRIPTION</title>
    <para>
      These functions provide hostname-to-address and
      address-to-hostname lookups by means of the lightweight resolver.
      They are similar to the standard
      <citerefentry>
        <refentrytitle>gethostent</refentrytitle><manvolnum>3</manvolnum>
      </citerefentry>
      functions provided by most operating systems.
      They use a
      <type>struct hostent</type>
      which is usually defined in
      <filename>&lt;namedb.h&gt;</filename>.
    </para>
    <para><programlisting>
struct  hostent {
        char    *h_name;        /* official name of host */
        char    **h_aliases;    /* alias list */
        int     h_addrtype;     /* host address type */
        int     h_length;       /* length of address */
        char    **h_addr_list;  /* list of addresses from name server */
};
#define h_addr  h_addr_list[0]  /* address, for backward compatibility */
</programlisting>
    </para>
    <para>
      The members of this structure are:
      <variablelist>
        <varlistentry>
          <term><constant>h_name</constant></term>
          <listitem>
            <para>
              The official (canonical) name of the host.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><constant>h_aliases</constant></term>
          <listitem>
            <para>
              A NULL-terminated array of alternate names (nicknames) for the
              host.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><constant>h_addrtype</constant></term>
          <listitem>
            <para>
              The type of address being returned &mdash;
              <type>PF_INET</type>
              or
              <type>PF_INET6</type>.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><constant>h_length</constant></term>
          <listitem>
            <para>
              The length of the address in bytes.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><constant>h_addr_list</constant></term>
          <listitem>
            <para>
              A <type>NULL</type>
              terminated array of network addresses for the host.
              Host addresses are returned in network byte order.