connect

Initiates a connection on a socket.

Format 

#include  <socket.h>

int connect  (int s, struct sockaddr *name, int
             namelen);
Routine Variants This socket routine has a variant named __bsd44_connect. Enabled by defining _SOCKADDR_LEN, this variant implements 4.4BSD-compatible semantics. See Section A.7 for more information.

Arguments

s
A socket descriptor that has been created with socket.
name
The address of a structure that specifies the name of the remote socket in the format specific to the address family (AF_ INET).
namelen
The size, in bytes, of the structure pointed to by name.

Description

If s is a socket descriptor of type SOCK_DGRAM, then this call permanently specifies the peer to which data is to be sent. If it is of type SOCK_STREAM, then this call attempts to make a connection to another socket.

Each communications space interprets the name parameter in its own way. This argument specifies the socket to which the socket specified in s is to be connected.

See also accept, select, socket, getsockname, and shutdown in this appendix.

Return Values
0  Indicates success. 
-1  Indicates an error; errno is set to one of the following:

  • EBADF - The socket descriptor is invalid.

  • ENOTSOCK - The socket descriptor references a file, not a socket.

  • EADDRNOTAVAIL - specified address is not available from the local machine.

  • EAFNOSUPPORT - Address in the specified address family cannot be used with this socket.

  • EISCONN - The socket is already connected.

  • ETIMEOUT - Connection establishment timed out without establishing a connection.

  • ECONNREFUSED - The attempt to connect was forcefully rejected.

  • ENETUNREACH - The network is not reachable from this host.

  • EADDRINUSE - The specified Internet address and ports are already in use.

  • EFAULT - The name parameter is not a valid part of the user address space.

  • EWOULDBLOCK - The socket is nonblocking and the connection cannot be completed immediately. It is possible to select the socket while it is connecting by selecting it for writing.
 

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