BPX1GHA (gethostbyaddr) example
The following code returns a pointer to a HOSTENT structure, which contains the alias names and the internet addresses of a host whose address is specified as input. For the callable service, see gethostbyaddr (BPX1GHA, BPX4GHA) Get the IP address and alias of a host name for the specified IP address. AMODE 64 callers use BPX4GHA (gethostbyaddr) example.
The HOSTENT structure has the following
format:
- h_name - The address of the host name returned by the service. The host name is a variable length field that is ended by x'00'. #$
- h_aliases - The address of a list of addresses that point to the alias names returned by the service. The list is ended by the pointer x'00000000'. Each alias name is a variable length field that is ended by x'00'.
- h_addrtype - The value 2, which signifies AF_INET.
- h_length - The length of the host internet addresses pointed to by h_addr_list.
- h-addr_list - The address of a list of addresses that point to the host internet addresses returned by this service. The list is ended by the pointer x'00000000'.
* MVC HOST_ADDR,=XL4'C90E0256' IP Address of Host
MVC HOST_ADDRLEN,=F'4' Address length
SPACE ,
CALL BPX1GHA, Get host by address +
(HOST_ADDR, Input: IP address of queried HOST +
HOST_ADDRLEN, Input: Length of IP address +
HOSTENT_PTR, Output: 0 or -> HOSTENT structure +
=A(AF_INET), Input: Domain - AF_INET +
RETVAL, Return code +
RETCODE, Return code +
RSNCODE), Reason code +
VL,MF=(E,PLIST) ----------------------------------