CONNECT(2) System Calls Manual CONNECT(2)
+
+NAME
+ connect - initiate a connection on a socket
+
+SYNOPSIS
+ #include <sys/types.h>
+ #include <sys/socket.h>
+
+ int
+ connect(int s, const struct sockaddr *name, socklen_t namelen);
+
+DESCRIPTION
+ The parameter s is a socket. If it is of type SOCK_DGRAM, this call
+ specifies the peer with which the socket is to be associated; this
+ address is that to which datagrams are to be sent, and the only address
+ from which datagrams are to be received. If the socket is of type
+ SOCK_STREAM, this call attempts to make a connection to another socket.
+ The other socket is specified by name, which is an address in the commu-
+ nications space of the socket. Each communications space interprets the
+ name parameter in its own way. Generally, stream sockets may success-
+ fully connect() only once; datagram sockets may use connect() multiple
+ times to change their association. Datagram sockets may dissolve the
+ association by connecting to an invalid address, such as a null address.
+
+RETURN VALUES
+ If the connection or binding succeeds, 0 is returned. Otherwise a -1 is
+ returned, and a more specific error code is stored in errno.
+
+ERRORS
+ The connect() call fails if:
+
+ [EBADF] S is not a valid descriptor.
+
+ [ENOTSOCK] S is a descriptor for a file, not a socket.
+
+ [EADDRNOTAVAIL] The specified address is not available on this
+ machine.
+
+ [EAFNOSUPPORT] Addresses in the specified address family cannot be
+ used with this socket.
+
+ [EISCONN] The socket is already connected.
+
+ [ETIMEDOUT] Connection establishment timed out without establish-
+ ing a connection.
+
+ [EINVAL] A TCP connection with a local broadcast, the all-ones
+ or a multicast address as the peer was attempted.
+
+ [ECONNREFUSED] The attempt to connect was forcefully rejected.
+
+ [EINTR] A connect was interrupted before it succeeded by the
+ delivery of a signal.
+
+ [ENETUNREACH] The network isn't reachable from this host.
+
+ [EADDRINUSE] The address is already in use.
+
+ [EFAULT] The name parameter specifies an area outside the pro-
+ cess address space.
+
+ [EINPROGRESS] The socket is non-blocking and the connection cannot
+ be completed immediately. It is possible to select(2)
+ or poll(2) for completion by selecting the socket for
+ writing, and also use getsockopt(2) with SO_ERROR to
+ check for error conditions.
+
+ [EALREADY] The socket is non-blocking and a previous connection
+ attempt has not yet been completed.
+
+ The following errors are specific to connecting names in the UNIX domain.
+ These errors may not apply in future versions of the UNIX IPC domain.
+
+ [ENOTDIR] A component of the path prefix is not a directory.
+
+ [ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} charac-
+ ters, or an entire path name exceeded {PATH_MAX} char-
+ acters.
+
+ [ENOENT] The named socket does not exist.
+
+ [EACCES] Search permission is denied for a component of the
+ path prefix.
+
+ [EACCES] Write access to the named socket is denied.
+
+ [ELOOP] Too many symbolic links were encountered in translat-
+ ing the pathname.
+
+SEE ALSO
+ accept(2), getsockname(2), getsockopt(2), poll(2), select(2), socket(2)
+
+HISTORY
+ The connect() function call appeared in 4.2BSD.
+
+BSD February 15, 1999 BSD
+ |