- This functionality is
rarely used:
- Find host information (e.g., the symbolic host name) using a binary IP address
In case you do need it, the function is:
gethostbyaddr( ... )
- Find host information
using its binary IP address:
- struct hostent*
gethostbyaddr( char *addr, int len,
int type)
- Input:
- addr =
starting address of the
4 byte IP address
in network byte order
- len = always set to
4 for
IPv4 address
- type = always set to AF_INET for IPv4 address
- addr =
starting address of the
4 byte IP address
in network byte order
- Output:
- a pointer to
a
host entry
data structure
- Returns NULL if error.
- a pointer to
a
host entry
data structure
- Input:
- struct hostent*
gethostbyaddr( char *addr, int len,
int type)
- gethostbyaddr( ) will
also return a
"host entry" data structure
(just like gethostbyname( )):
(It is the same data structure returned by gethostbyname()
Therefore, I will skip on how to use this data structure....
You can read the program below yourself....)
- Example Program:
(Demo above code)
- Prog file: click here
Notes:
- Compile with: cc -o gethostbyaddr gethostbyaddr.c -lnsl