connect

Requests a connection to be made on the given server_sockaddr. Returns 0 if successful, otherwise an exception is raised.

Parameter

• server_sockaddr - the struct sockaddr contained in a string

Example:

# Pull down Google's web page
require 'socket'
include Socket::Constants
socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
sockaddr = Socket.pack_sockaddr_in( 80, 'www.google.com' )
socket.connect( sockaddr )
socket.write( "GET / HTTP/1.0\r\n\r\n" )
results = socket.read 

Unix-based Exceptions

On unix-based systems the following system exceptions may be raised if the call to connect fails:

• Errno::EACCES - search permission is denied for a component of the prefix

path or write access to the +socket+ is denided

• Errno::EADDRINUSE - the sockaddr is already in use

• Errno::EADDRNOTAVAIL - the specified sockaddr is not available from the

local machine

• Errno::EAFNOSUPPORT - the specified sockaddr is not a valid address for

the address family of the specified +socket+

• Errno::EALREADY - a connection is already in progress for the specified

socket

• Errno::EBADF - the socket is not a valid file descriptor

• Errno::ECONNREFUSED - the target sockaddr was not listening for connections

refused the connection request

• Errno::ECONNRESET - the remote host reset the connection request

• Errno::EFAULT - the sockaddr cannot be accessed

• Errno::EHOSTUNREACH - the destination host cannot be reached (probably

because the host is down or a remote router cannot reach it)

• Errno::EINPROGRESS - the O_NONBLOCK is set for the socket and the

connection cnanot be immediately established; the connection will be
established asynchronously

• Errno::EINTR - the attempt to establish the connection was interrupted by

delivery of a signal that was caught; the connection will be established
asynchronously

• Errno::EISCONN - the specified socket is already connected

• Errno::EINVAL - the address length used for the sockaddr is not a valid

length for the address family or there is an invalid family in _sockaddr_ 

• Errno::ENAMETOOLONG - the pathname resolved had a length which exceeded

PATH_MAX

• Errno::ENETDOWN - the local interface used to reach the destination is down

• Errno::ENETUNREACH - no route to the network is present

• Errno::ENOBUFS - no buffer space is available

• Errno::ENOSR - there were insufficient STREAMS resources available to

complete the operation

• Errno::ENOTSOCK - the socket argument does not refer to a socket

• Errno::EOPNOTSUPP - the calling socket is listening and cannot be connected

• Errno::EPROTOTYPE - the sockaddr has a different type than the socket

bound to the specified peer address

• Errno::ETIMEDOUT - the attempt to connect time out before a connection

was made.

On unix-based systems if the address family of the calling socket is AF_UNIX the follow exceptions may be raised if the call to connect fails:

• Errno::EIO - an i/o error occured while reading from or writing to the

file system

• Errno::ELOOP - too many symbolic links were encountered in translating

the pathname in _sockaddr_

• Errno::ENAMETOOLLONG - a component of a pathname exceeded NAME_MAX

characters, or an entired pathname exceeded PATH_MAX characters

• Errno::ENOENT - a component of the pathname does not name an existing file

or the pathname is an empty string

• Errno::ENOTDIR - a component of the path prefix of the pathname in sockaddr

is not a directory 

Windows Exceptions

On Windows systems the following system exceptions may be raised if the call to connect fails:

• Errno::ENETDOWN - the network is down

• Errno::EADDRINUSE - the socket’s local address is already in use

• Errno::EINTR - the socket was cancelled

• Errno::EINPROGRESS - a blocking socket is in progress or the service provider

is still processing a callback function. Or a nonblocking connect call is 
in progress on the +socket+.

• Errno::EALREADY - see Errno::EINVAL

• Errno::EADDRNOTAVAIL - the remote address is not a valid address, such as

ADDR_ANY TODO check ADDRANY TO INADDR_ANY

• Errno::EAFNOSUPPORT - addresses in the specified family cannot be used with

with this +socket+

• Errno::ECONNREFUSED - the target sockaddr was not listening for connections

refused the connection request

• Errno::EFAULT - the socket’s internal address or address length parameter

is too small or is not a valid part of the user space address

• Errno::EINVAL - the socket is a listening socket

• Errno::EISCONN - the socket is already connected

• Errno::ENETUNREACH - the network cannot be reached from this host at this time

• Errno::EHOSTUNREACH - no route to the network is present

• Errno::ENOBUFS - no buffer space is available

• Errno::ENOTSOCK - the socket argument does not refer to a socket

• Errno::ETIMEDOUT - the attempt to connect time out before a connection

was made.

• Errno::EWOULDBLOCK - the socket is marked as nonblocking and the

connection cannot be completed immediately

• Errno::EACCES - the attempt to connect the datagram socket to the

broadcast address failed

See

• connect manual pages on unix-based systems

• connect function in Microsoft’s Winsock functions reference

static VALUE
sock_connect(VALUE sock, VALUE addr)
{
    rb_io_t *fptr;
    int fd, n;

    StringValue(addr);
    addr = rb_str_new4(addr);
    GetOpenFile(sock, fptr);
    fd = fptr->fd;
    n = ruby_connect(fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_LEN(addr), 0);
    if (n < 0) {
        rb_sys_fail("connect(2)");
    }

    return INT2FIX(n);
}