TCP/IP Tutorial and Technical Overview - IBM Redbooks

► Send and receive data on a socket
Format:
sendmsg(sockfd, data, datalength, flags)
recvmsg(sockfd, data, datalength, flags)
Definition of fields:
sockfd This is the socket across which the data will be sent or read.
data This is the data to be sent, or the buffer into which the read
data will be placed.
datalength When writing data, this is the length of the data to be written.
When reading data, this is the amount of data to be read
from the socket.
flags This field, which is in many implementations optional,
provides any specific information to TCP/IP regarding any
special actions to be taken on the socket when sending or
receiving the data.
Note: Other variations of sendmsg() and recv() can be as follows:
sendmsg(): send(), sendto(), write()
recvmsg(): recv(), recvfrom(), read()
RFC 3493 does not specifically discuss the fields passed on the sendmsg()
function. The fields discussed earlier are drawn from those typically used
by most implementations.
► Close a socket
Format:
close(sockfd)
Definition of fields:
sockfd This is the socket which is to be closed.
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