pSOSystem System Calls - Read

pNA+ System Calls getsockopt
getsockopt Gets options on a socket.
#include
long getsockopt(
int s, /* socket descriptor */
int level, /* SOL_SOCKET, IPPROTO_IP, */
/* or IPPROTO_TCP */
int optname, /* retrieval option */
char *optval, /* return buffer */
int *optlen /* input/output buffer size */
)
Description
Arguments
The getsockopt() system call obtains the status of options associated with the
specified socket. Socket level, IP protocol level, or TCP protocol level options may be
retrieved.
s Specifies the socket.
level Specifies the level of the option to be queried and must be set to
SOL_SOCKET for socket level operations, IPPROTO_IP for IP
protocol level operations, or IPPROTO_TCP for TCP protocol
level operations.
optname Specifies the option to be queried, and uses a symbolic constant.
The symbolic constants available for each level are provided
below and in .
optval Points to a buffer where getsockopt() stores the value for the
requested option. For most options, an int is returned in the
buffer pointed to by optval. A nonzero value means the option
is set, and a 0 means the option is off.
optlen An input-output parameter. On input, it should contain the size
of the buffer pointed to by optval. On output, it contains the
actual size of the value returned in the optval buffer.
pSOSystem System Calls 4-17
4