The following table contains a summary of
the BSD Sockets
system calls.
Table 8-1 BSD
Sockets System Calls
System Call | Description |
|---|
socket | Creates
a socket, or communication endpoint for the calling process. |
bind | Assigns
a socket address to the socket specified by the calling process. |
listen | Sets up a queue for incoming connection requests.
(Stream
sockets only.) |
connect | For stream sockets, requests and creates
a connection between the remote socket (specified by address) and
the socket (specified by descriptor) of the calling process. For
datagram
sockets, permanently specifies the remote peer socket. |
accept | Receives
a connection between the socket of the calling process and the socket
specified in the associated connect call. (Stream sockets only.) |
send,
sendto, sendmsg | Sends data from the specified socket. |
recv,
recvfrom, recvmsg | Receives data at the specified socket. |
shutdown | Disconnects
the specified socket. |
getsockname | Gets
the socket address of the specified socket. |
getsockopt,
setsockopt | Gets,
or sets, the options associated with a socket. |
getpeername | Gets
the name of the peer socket connected to the specified socket. |
The following table contains a summary of the other system
calls that can be used with BSD Sockets.
Table 8-2 Other
BSD Sockets System Calls
System Call | Description |
|---|
read | Can
be used
to read data at stream or datagram sockets
just like recv or recvfrom , without the benefit of the recv
flags. Read offers implementation independence; the descriptor can
be for a file, a socket or any other object. |
write | Can
be used to write data from stream sockets (and datagram
sockets if you declare a default remote socket address) just like
send. Write offers implementation independence; the descriptor can
be for a file, a socket or any other object. |
close | Deallocates socket descriptors. The last close
can be used to destroy a socket. Close does a graceful disconnect
or a hard close, depending on the LINGER option. Refer to the sections
on "Closing a Socket." |
select | Can
be used
to improve efficiency for a process that accesses multiple sockets
or other I/O devices simultaneously. Refer to the sections on "Synchronous
I/O Multiplexing with Select." |
ioctl | Can
be used for finding the number of receivable bytes with FIONREAD
and for setting the nonblocking I/O flag with FIOSBNBIO. Can also
be used for setting a socket to receive asynchronous signals with
FIOASYNC
. |
fcntl | Can
be used for duplicating a socket descriptor and for setting the
O_NDELAY
or O_NONBLOCK
flag. |
BSD Sockets attempts to isolate host-specific information
from applications by providing library calls that return the necessary information.
The following table contains a summary of the library calls
used with BSD Sockets. The library calls are in the common "c"
library named libc.sl. Therefore,
there is no need to specify any library name on the cc
command line to use these library calls, libc.sl
is used automatically.
Table 8-3 Library
Calls
Library Call | Description |
|---|
inet_addr inet_lnaof inet_makeaddr inet_netof inet_network | internet
address manipulation routines |
setservent endservent getservbyname getservbyport getservent | get
or set service entry |
setprotoent endprotoent getprotobyname getprotobynumber getprotoent | get
or set protocol entry |
setnetent endnetent getnetbyaddr getnetbyname getnetent | get
or set network entry |
sethostent endhostent gethostbyaddr gethostbyname gethostent | get or
set host entry |
