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
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