gethostbyaddr

Searches the host database sequentially from the beginning of the database for a host record with a given address.

Format

#include  <netdb.h>

struct hostent *gethostbyaddr  (char *addr, int
                               len, int type);

Routine Variants This socket routine has a variant named __bsd44_gethostbyaddr. Enabled by defining _SOCKADDR_LEN, this variant implements 4.4BSD-compatible semantics. See Section A.7 for more information.

Arguments

addr: A pointer to a series of bytes in network order specifying the address of the host sought. This argument does not point to an ASCII string.
len: The number of bytes in the address pointed to by the addr argument.
type: The type of address format being sought. Currently, only AF_ INET (defined in <socket.h>) is supported.)

Description

This routine finds the first host record in the host database with the given address.

The gethostbyaddr routine uses a common static area for its return values. This means that subsequent calls this routine will overwrite any existing host entry. You must make a copy of the host entry if you wish to save it.

Return Values

NULL Indicates an error.

x A pointer to an object having the hostent structure. See <netdb.h> for a description of the hostent structure.
Depending on the error condition and the socket implementation selected, errno or h_errno might be set to further indicate the error. (See sections A.5 and A.6.)

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NULL	Indicates an error.
x	A pointer to an object having the hostent structure. See <netdb.h> for a description of the hostent structure. Depending on the error condition and the socket implementation selected, errno or h_errno might be set to further indicate the error. (See sections A.5 and A.6.)