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Diffstat (limited to 'newlib/libc/sys/linux/net/gethostbyname.3')
-rw-r--r-- | newlib/libc/sys/linux/net/gethostbyname.3 | 380 |
1 files changed, 0 insertions, 380 deletions
diff --git a/newlib/libc/sys/linux/net/gethostbyname.3 b/newlib/libc/sys/linux/net/gethostbyname.3 deleted file mode 100644 index 51ed2f864..000000000 --- a/newlib/libc/sys/linux/net/gethostbyname.3 +++ /dev/null @@ -1,380 +0,0 @@ -.\" Copyright (c) 1983, 1987, 1991, 1993 -.\" The Regents of the University of California. All rights reserved. -.\" -.\" Redistribution and use in source and binary forms, with or without -.\" modification, are permitted provided that the following conditions -.\" are met: -.\" 1. Redistributions of source code must retain the above copyright -.\" notice, this list of conditions and the following disclaimer. -.\" 2. Redistributions in binary form must reproduce the above copyright -.\" notice, this list of conditions and the following disclaimer in the -.\" documentation and/or other materials provided with the distribution. -.\" 3. All advertising materials mentioning features or use of this software -.\" must display the following acknowledgement: -.\" This product includes software developed by the University of -.\" California, Berkeley and its contributors. -.\" 4. Neither the name of the University nor the names of its contributors -.\" may be used to endorse or promote products derived from this software -.\" without specific prior written permission. -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND -.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE -.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS -.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) -.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY -.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -.\" SUCH DAMAGE. -.\" -.\" From: @(#)gethostbyname.3 8.4 (Berkeley) 5/25/95 -.\" $FreeBSD: src/lib/libc/net/gethostbyname.3,v 1.26 2002/01/14 16:59:00 ru Exp $ -.\" -.Dd May 25, 1995 -.Dt GETHOSTBYNAME 3 -.Os -.Sh NAME -.Nm gethostbyname , -.Nm gethostbyname2 , -.Nm gethostbyaddr , -.Nm gethostent , -.Nm sethostent , -.Nm endhostent , -.Nm herror , -.Nm hstrerror -.Nd get network host entry -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.In netdb.h -.Vt extern int h_errno ; -.Ft struct hostent * -.Fn gethostbyname "const char *name" -.Ft struct hostent * -.Fn gethostbyname2 "const char *name" "int af" -.Ft struct hostent * -.Fn gethostbyaddr "const char *addr" "int len" "int type" -.Ft struct hostent * -.Fn gethostent void -.Ft void -.Fn sethostent "int stayopen" -.Ft void -.Fn endhostent void -.Ft void -.Fn herror "const char *string" -.Ft const char * -.Fn hstrerror "int err" -.Sh DESCRIPTION -.Bf -symbolic -The -.Xr getaddrinfo 3 -and -.Xr getnameinfo 3 -functions are preferred over the -.Fn gethostbyname , -.Fn gethostbyname2 , -and -.Fn gethostbyaddr -functions. -.Ef -.Pp -The -.Fn gethostbyname , -.Fn gethostbyname2 -and -.Fn gethostbyaddr -functions -each return a pointer to an object with the -following structure describing an internet host -referenced by name or by address, respectively. -.Pp -The -.Fa name -parameter passed to -.Fn gethostbyname -or -.Fn gethostbyname2 -should point to a -.Dv NUL Ns -terminated -hostname. -The -.Fa addr -parameter passed to -.Fn gethostbyaddr -should point to an address which is -.Fa len -bytes long, -in binary form -(i.e. not an IP address in human readable -.Tn ASCII -form). -The -.Fa type -parameter specifies the address family -(e.g.\& -.Dv AF_INET , AF_INET6 , -etc.) of this address. -.Pp -The structure returned contains either the information obtained from the name -server, -.Xr named 8 , -broken-out fields from a line in -.Pa /etc/hosts , -or database entries supplied by the -.Xr yp 8 -system. -The order of the lookups is controlled by the -.Sq hosts -entry in -.Xr nsswitch.conf 5 . -.Bd -literal -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 */ -.Ed -.Pp -The members of this structure are: -.Bl -tag -width h_addr_list -.It Va h_name -Official name of the host. -.It Va h_aliases -A -.Dv NULL Ns -terminated -array of alternate names for the host. -.It Va h_addrtype -The type of address being returned; usually -.Dv AF_INET . -.It Va h_length -The length, in bytes, of the address. -.It Va h_addr_list -A -.Dv NULL Ns -terminated -array of network addresses for the host. -Host addresses are returned in network byte order. -.It Va h_addr -The first address in -.Va h_addr_list ; -this is for backward compatibility. -.El -.Pp -When using the nameserver, -.Fn gethostbyname -and -.Fn gethostbyname2 -will search for the named host in the current domain and its parents -unless the name ends in a dot. -If the name contains no dot, and if the environment variable -.Dq Ev HOSTALIASES -contains the name of an alias file, the alias file will first be searched -for an alias matching the input name. -See -.Xr hostname 7 -for the domain search procedure and the alias file format. -.Pp -The -.Fn gethostbyname2 -function is an evolution of -.Fn gethostbyname -which is intended to allow lookups in address families other than -.Dv AF_INET , -for example -.Dv AF_INET6 . -.Pp -The -.Fn sethostent -function -may be used to request the use of a connected -.Tn TCP -socket for queries. -If the -.Fa stayopen -flag is non-zero, -this sets the option to send all queries to the name server using -.Tn TCP -and to retain the connection after each call to -.Fn gethostbyname , -.Fn gethostbyname2 -or -.Fn gethostbyaddr . -Otherwise, queries are performed using -.Tn UDP -datagrams. -.Pp -The -.Fn endhostent -function -closes the -.Tn TCP -connection. -.Pp -The -.Fn herror -function writes a message to the diagnostic output consisting of the -string parameter -.Fa s , -the constant string -.Qq Li ":\ " , -and a message corresponding to the value of -.Va h_errno . -.Pp -The -.Fn hstrerror -function returns a string which is the message text corresponding to the -value of the -.Fa err -parameter. -.Sh FILES -.Bl -tag -width /etc/nsswitch.conf -compact -.It Pa /etc/hosts -.It Pa /etc/nsswitch.conf -.It Pa /etc/resolv.conf -.El -.Sh EXAMPLES -Print out the hostname associated with a specific IP address: -.Bd -literal -offset indent -const char *ipstr = "127.0.0.1"; -struct in_addr ip; -struct hostent *hp; - -if (!inet_aton(ipstr, &ip)) - errx(1, "can't parse IP address %s", ipstr); - -if ((hp = gethostbyaddr((const char *)&ip, - sizeof ip, AF_INET)) == NULL) - errx(1, "no name associated with %s", ipstr); - -printf("name associated with %s is %s\en", ipstr, hp->h_name); -.Ed -.Sh DIAGNOSTICS -Error return status from -.Fn gethostbyname , -.Fn gethostbyname2 -and -.Fn gethostbyaddr -is indicated by return of a -.Dv NULL -pointer. -The external integer -.Va h_errno -may then be checked to see whether this is a temporary failure -or an invalid or unknown host. -The routine -.Fn herror -can be used to print an error message describing the failure. -If its argument -.Fa string -is -.Pf non- Dv NULL , -it is printed, followed by a colon and a space. -The error message is printed with a trailing newline. -.Pp -The variable -.Va h_errno -can have the following values: -.Bl -tag -width HOST_NOT_FOUND -.It Dv HOST_NOT_FOUND -No such host is known. -.It Dv TRY_AGAIN -This is usually a temporary error -and means that the local server did not receive -a response from an authoritative server. -A retry at some later time may succeed. -.It Dv NO_RECOVERY -Some unexpected server failure was encountered. -This is a non-recoverable error. -.It Dv NO_DATA -The requested name is valid but does not have an IP address; -this is not a temporary error. -This means that the name is known to the name server but there is no address -associated with this name. -Another type of request to the name server using this domain name -will result in an answer; -for example, a mail-forwarder may be registered for this domain. -.El -.Sh SEE ALSO -.Xr getaddrinfo 3 , -.Xr getnameinfo 3 , -.Xr inet_aton 3 , -.Xr resolver 3 , -.Xr hosts 5 , -.Xr hostname 7 , -.Xr named 8 -.Sh CAVEAT -The -.Fn gethostent -function -is defined, and -.Fn sethostent -and -.Fn endhostent -are redefined, -when -.Xr libc 3 -is built to use only the routines to lookup in -.Pa /etc/hosts -and not the name server. -.Pp -The -.Fn gethostent -function -reads the next line of -.Pa /etc/hosts , -opening the file if necessary. -.Pp -The -.Fn sethostent -function -opens and/or rewinds the file -.Pa /etc/hosts . -If the -.Fa stayopen -argument is non-zero, -the file will not be closed after each call to -.Fn gethostbyname , -.Fn gethostbyname2 -or -.Fn gethostbyaddr . -.Pp -The -.Fn endhostent -function -closes the file. -.Sh HISTORY -The -.Fn herror -function appeared in -.Bx 4.3 . -The -.Fn endhostent , -.Fn gethostbyaddr , -.Fn gethostbyname , -.Fn gethostent , -and -.Fn sethostent -functions appeared in -.Bx 4.2 . -The -.Fn gethostbyname2 -function first appeared in -.Tn BIND -version 4.9.4. -.Sh BUGS -These functions use static data storage; -if the data is needed for future use, it should be -copied before any subsequent calls overwrite it. -Only the Internet -address format is currently understood. -.Pp -.Fn gethostbyname2 -cannot perform -.Dv AF_INET6 -lookups over NIS. -.Xr getaddrinfo 3 -must be used instead. |