lib/liblwres/man/lwres_getnameinfo.html

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  17 <HTML
  18 ><HEAD
  19 ><TITLE
  20 >lwres_getnameinfo</TITLE
  21 ><META
  22 NAME="GENERATOR"
  23 CONTENT="Modular DocBook HTML Stylesheet Version 1.61
  24 "></HEAD
  25 ><BODY
  26 CLASS="REFENTRY"
  27 BGCOLOR="#FFFFFF"
  28 TEXT="#000000"
  29 LINK="#0000FF"
  30 VLINK="#840084"
  31 ALINK="#0000FF"
  32 ><H1
  33 ><A
  34 NAME="AEN1"
  35 >lwres_getnameinfo</A
  36 ></H1
  37 ><DIV
  38 CLASS="REFNAMEDIV"
  39 ><A
  40 NAME="AEN8"
  41 ></A
  42 ><H2
  43 >Name</H2
  44 >lwres_getnameinfo&nbsp;--&nbsp;lightweight resolver socket address structure to hostname and service name</DIV
  45 ><DIV
  46 CLASS="REFSYNOPSISDIV"
  47 ><A
  48 NAME="AEN11"
  49 ></A
  50 ><H2
  51 >Synopsis</H2
  52 ><DIV
  53 CLASS="FUNCSYNOPSIS"
  54 ><A
  55 NAME="AEN12"
  56 ></A
  57 ><P
  58 ></P
  59 ><PRE
  60 CLASS="FUNCSYNOPSISINFO"
  61 >#include &lt;lwres/netdb.h&gt;</PRE
  62 ><P
  63 ><CODE
  64 ><CODE
  65 CLASS="FUNCDEF"
  66 >int
  67 lwres_getnameinfo</CODE
  68 >(const struct sockaddr *sa, size_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags);</CODE
  69 ></P
  70 ><P
  71 ></P
  72 ></DIV
  73 ></DIV
  74 ><DIV
  75 CLASS="REFSECT1"
  76 ><A
  77 NAME="AEN24"
  78 ></A
  79 ><H2
  80 >DESCRIPTION</H2
  81 ><P
  82 > This function is equivalent to the <SPAN
  83 CLASS="CITEREFENTRY"
  84 ><SPAN
  85 CLASS="REFENTRYTITLE"
  86 >getnameinfo</SPAN
  87 >(3)</SPAN
  88 > function defined in RFC2133.
  89 <TT
  90 CLASS="FUNCTION"
  91 >lwres_getnameinfo()</TT
  92 > returns the hostname for the
  93 <SPAN
  94 CLASS="TYPE"
  95 >struct sockaddr</SPAN
  96 > <TT
  97 CLASS="PARAMETER"
  98 ><I
  99 >sa</I
 100 ></TT
 101 > which is
 102 <TT
 103 CLASS="PARAMETER"
 104 ><I
 105 >salen</I
 106 ></TT
 107 > bytes long.  The hostname is of length
 108 <TT
 109 CLASS="PARAMETER"
 110 ><I
 111 >hostlen</I
 112 ></TT
 113 > and is returned via
 114 <TT
 115 CLASS="PARAMETER"
 116 ><I
 117 >*host.</I
 118 ></TT
 119 > The maximum length of the hostname is
 120 1025 bytes: <TT
 121 CLASS="CONSTANT"
 122 >NI_MAXHOST</TT
 123 >.</P
 124 ><P
 125 > The name of the service associated with the port number in
 126 <TT
 127 CLASS="PARAMETER"
 128 ><I
 129 >sa</I
 130 ></TT
 131 > is returned in <TT
 132 CLASS="PARAMETER"
 133 ><I
 134 >*serv.</I
 135 ></TT
 136 >
 137 It is <TT
 138 CLASS="PARAMETER"
 139 ><I
 140 >servlen</I
 141 ></TT
 142 > bytes long.  The maximum length
 143 of the service name is <TT
 144 CLASS="CONSTANT"
 145 >NI_MAXSERV</TT
 146 > - 32 bytes.</P
 147 ><P
 148 > The <TT
 149 CLASS="PARAMETER"
 150 ><I
 151 >flags</I
 152 ></TT
 153 > argument sets the following
 154 bits:
 155 <P
 156 ></P
 157 ><DIV
 158 CLASS="VARIABLELIST"
 159 ><DL
 160 ><DT
 161 ><TT
 162 CLASS="CONSTANT"
 163 >NI_NOFQDN</TT
 164 ></DT
 165 ><DD
 166 ><P
 167 >A fully qualified domain name is not required for local hosts.
 168 The local part of the fully qualified domain name is returned instead.</P
 169 ></DD
 170 ><DT
 171 ><TT
 172 CLASS="CONSTANT"
 173 >NI_NUMERICHOST</TT
 174 ></DT
 175 ><DD
 176 ><P
 177 >Return the address in numeric form, as if calling inet_ntop(),
 178 instead of a host name.</P
 179 ></DD
 180 ><DT
 181 ><TT
 182 CLASS="CONSTANT"
 183 >NI_NAMEREQD</TT
 184 ></DT
 185 ><DD
 186 ><P
 187 >A name is required. If the hostname cannot be found in the DNS and
 188 this flag is set, a non-zero error code is returned.
 189 If the hostname is not found and the flag is not set, the
 190 address is returned in numeric form.</P
 191 ></DD
 192 ><DT
 193 ><TT
 194 CLASS="CONSTANT"
 195 >NI_NUMERICSERV</TT
 196 ></DT
 197 ><DD
 198 ><P
 199 >The service name is returned as a digit string representing the port number.</P
 200 ></DD
 201 ><DT
 202 ><TT
 203 CLASS="CONSTANT"
 204 >NI_DGRAM</TT
 205 ></DT
 206 ><DD
 207 ><P
 208 >Specifies that the service being looked up is a datagram
 209 service,  and causes getservbyport() to be called with a second
 210 argument of "udp" instead of its default of "tcp".  This is required
 211 for the few ports (512-514) that have different services for UDP and
 212 TCP.</P
 213 ></DD
 214 ></DL
 215 ></DIV
 216 ></P
 217 ></DIV
 218 ><DIV
 219 CLASS="REFSECT1"
 220 ><A
 221 NAME="AEN70"
 222 ></A
 223 ><H2
 224 >RETURN VALUES</H2
 225 ><P
 226 ><TT
 227 CLASS="FUNCTION"
 228 >lwres_getnameinfo()</TT
 229 >
 230 returns 0 on success or a non-zero error code if an error occurs.</P
 231 ></DIV
 232 ><DIV
 233 CLASS="REFSECT1"
 234 ><A
 235 NAME="AEN74"
 236 ></A
 237 ><H2
 238 >SEE ALSO</H2
 239 ><P
 240 ><SPAN
 241 CLASS="CITEREFENTRY"
 242 ><SPAN
 243 CLASS="REFENTRYTITLE"
 244 >RFC2133</SPAN
 245 ></SPAN
 246 >,
 247 <SPAN
 248 CLASS="CITEREFENTRY"
 249 ><SPAN
 250 CLASS="REFENTRYTITLE"
 251 >getservbyport</SPAN
 252 >(3)</SPAN
 253 >,
 254 <SPAN
 255 CLASS="CITEREFENTRY"
 256 ><SPAN
 257 CLASS="REFENTRYTITLE"
 258 >lwres</SPAN
 259 >(3)</SPAN
 260 >,
 261 <SPAN
 262 CLASS="CITEREFENTRY"
 263 ><SPAN
 264 CLASS="REFENTRYTITLE"
 265 >lwres_getnameinfo</SPAN
 266 >(3)</SPAN
 267 >,
 268 <SPAN
 269 CLASS="CITEREFENTRY"
 270 ><SPAN
 271 CLASS="REFENTRYTITLE"
 272 >lwres_getnamebyaddr</SPAN
 273 >(3)</SPAN
 274 >.
 275 <SPAN
 276 CLASS="CITEREFENTRY"
 277 ><SPAN
 278 CLASS="REFENTRYTITLE"
 279 >lwres_net_ntop</SPAN
 280 >(3)</SPAN
 281 >.</P
 282 ></DIV
 283 ><DIV
 284 CLASS="REFSECT1"
 285 ><A
 286 NAME="AEN94"
 287 ></A
 288 ><H2
 289 >BUGS</H2
 290 ><P
 291 >RFC2133 fails to define what the nonzero return values of
 292 <SPAN
 293 CLASS="CITEREFENTRY"
 294 ><SPAN
 295 CLASS="REFENTRYTITLE"
 296 >getnameinfo</SPAN
 297 >(3)</SPAN
 298 >
 299 are.</P
 300 ></DIV
 301 ></BODY
 302 ></HTML
 303 >