#include <sys/types.h> #include <sys/socket.h>
int send(s, msg, len, flags) int s; char *msg; int len, flags;
int sendto(s, msg, len, flags, to, tolen) int s; char *msg; int len, flags; struct sockaddr *to; int tolen;
int sendmsg(s, msg, flags) int s; struct msghdr *msg; int flags;
s is a socket created with socket.2 send(), sendto(), and sendmsg() are used to transmit a message to another socket. send() may be used only when the socket is in a connected state, while sendto() and sendmsg() may be used at any time.
The address of the target is given by to with tolen specifying its size. The length of the message is given by len. If the message is too long to pass atomically through the underlying protocol, then the error EMSGSIZE is returned, and the message is not transmitted.
No indication of failure to deliver is implicit in a send(). Return values of -1 indicate some locally detected errors.
If no buffer space is available at the socket to hold the message to be transmitted, then send() normally blocks, unless the socket has been placed in non-blocking I/O mode. The select.2 call may be used to determine when it is possible to send more data.
If the process calling send(), sendmsg() or sendto() receives a signal before any data are buffered to be sent, the system call is restarted unless the calling process explicitly set the signal to interrupt these calls using sigvec() or sigaction() (see the discussions of SV_INTERRUPT on sigvec.2 and SA_INTERRUPT on sigaction.3v
The flags parameter is formed by ORing one or more of the following:
See recv.2 for a description of the msghdr structure.
the number of bytes sent.
to indicate the error.
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97