connect.2 (2010 09)

connect(2) connect(2)

[ENETUNREACH] The network is not reachable from this host.

For AF_CCITT only: X.25 Level 2 is down. The X.25 link is not working:

wires might be broken, connections are loose on the interface hoods at the

modem, the modem failed, or noise interfered with the line for an

extremely long period of time.

[ENOBUFS] No buffer space is available. The

connect() has failed.

[ENODEV] The x25ifname ﬁeld refers to a nonexistent interface.

[ENOENT] The ﬁle or the directory path speciﬁed in the target address for AF_UNIX

domain does not exist.

[ENOMEM] No memory is available. The

connect() has failed.

[ENOPROTOOPT] The remote system or an intermediate system in the communications path

does not support a protocol option sent by the local system. This option

may have been set using a

getsockopt() or

setsockopt() call, or

set as a system parameter.

[ENOSPC] All available virtual circuits are in use.

[ENOTSOCK] s is a valid ﬁle descriptor, but it is not a socket.

[EOPNOTSUPP] The socket referenced by s does not support

connect(); an attempt is

made to issue a connect() call on a listen() socket.

[ETIMEDOUT] Connection establishment timed out without establishing a connection.

One reason could be that the connection requests queue at the remote

socket may be full (see listen (2)).

OBSOLESCENCE

Currently, the

socklen_t and size_t types are the same size. This is compatible with the UNIX 95

and UNIX 03 proﬁles. However, in a future release, socklen_t might be a different size, but that

should not adversely affect application behavior in this case. Applications may use socklen_t now.

But applications that need to be portable to the UNIX 95 proﬁle should follow the X/Open speciﬁcation

(see xopen_networking(7)).

WARNINGS

Linking binary objects compiled to X/Open Sockets speciﬁcation and binary objects compiled to HP-UX

BSD Sockets speciﬁcation to the same executable may result in unexpected behavior, including applica-

tion abnormal termination and unexpected socket errors. See xopen_networking(7) for details and

remedy.

FUTURE DIRECTION

Currently, the default behavior is the HP-UX BSD Sockets; however, it might be changed to X/Open

Sockets in a future release. At that time, any HP-UX BSD Sockets behavior that is incompatible with

X/Open Sockets might be obsoleted. Applications that conform to the X/Open speciﬁcation now will

avoid migration problems (see xopen_networking(7)).

AUTHOR

connect() was developed by HP and the University of California, Berkeley.