.\" Copyright (C) 1994-2018 Altair Engineering, Inc.
.\" For more information, contact Altair at www.altair.com.
.\"
.\" This file is part of the PBS Professional ("PBS Pro") software.
.\"
.\" Open Source License Information:
.\"
.\" PBS Pro is free software. You can redistribute it and/or modify it under the
.\" terms of the GNU Affero General Public License as published by the Free
.\" Software Foundation, either version 3 of the License, or (at your option) any
.\" later version.
.\"
.\" PBS Pro is distributed in the hope that it will be useful, but WITHOUT ANY
.\" WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
.\" FOR A PARTICULAR PURPOSE.
.\" See the GNU Affero General Public License for more details.
.\"
.\" You should have received a copy of the GNU Affero General Public License
.\" along with this program.  If not, see <http://www.gnu.org/licenses/>.
.\"
.\" Commercial License Information:
.\"
.\" For a copy of the commercial license terms and conditions,
.\" go to: (http://www.pbspro.com/UserArea/agreement.html)
.\" or contact the Altair Legal Department.
.\"
.\" Altair’s dual-license business model allows companies, individuals, and
.\" organizations to create proprietary derivative works of PBS Pro and
.\" distribute them - whether embedded or bundled with other software -
.\" under a commercial license agreement.
.\"
.\" Use of Altair’s trademarks, including but not limited to "PBS™",
.\" "PBS Professional®", and "PBS Pro™" and Altair’s logos is subject to Altair's
.\" trademark licensing policies.
.\"
.TH pbs_connect 3B "18 March 2015" Local "PBS Professional"
.SH NAME
pbs_connect - connect to a PBS batch server
.SH SYNOPSIS
#include <pbs_error.h>
.br
#include <pbs_ifl.h>
.sp
.B int pbs_connect(\^char *server\^)
.RS 6
extern char *pbs_server;
.RE
.SH DESCRIPTION
A virtual stream (TCP/IP) connection is established with the server
specified by
.I server.
.LP
This function must be called before any of the other 
.B pbs_
functions.
They will transmit their batch requests over the connection established
by this function.
Multiple requests may be issued over the connection before it is closed.
.LP
The connection should be closed by a call to \f3pbs_disconnect\f1()
when all requests have been sent to the server.
.LP
The parameter called 
.I "server"
is of the form:
.RS 4
.I host_name[:port].
.RE
If 
.I port
is not specified, the standard PBS port number will be used.
.LP
If the parameter,
.I server,
is either the null string or a null pointer,
a connection will be opened to the default server.
The default server is defined
by (a) the setting of the environment
variable
.B PBS_DEFAULT
which contains a destination, or (b) by adding the parameter
.B PBS_SERVER
to the global configuration file /etc/pbs.conf.
.LP
The variable
.I pbs_server,
declared in pbs_ifl.h,
is set on return to point to the server
name to which pbs_connect() connected or attempted to connect.

.B pbs_connect()
determines whether or not the complex has a failover server configured.
It also determines which server is the primary and which is the secondary.
.B pbs_connect() 
is called by client commands, and directs traffic to the correct server.

In order to use 
.B pbs_connect 
with Windows, initialize the network
library and link with 
.B winsock2.  
To do this, call 
.B winsock_init() 
before calling 
.B pbs_connect(), 
and link against the 
.B ws2_32.lib 
library.

.SH SEE ALSO
qsub(1B),
pbs_alterjob(3B), pbs_deljob(3B), pbs_disconnect(3B), pbs_geterrmsg(3B), 
pbs_holdjob(3B), pbs_locjob(3B), pbs_manager(3B), pbs_movejob(3B), 
pbs_msgjob(3B), pbs_rerunjob(3B), pbs_rlsjob(3B), pbs_runjob(3B),
pbs_selectjob(3B), pbs_selstat(3B), pbs_sigjob(3B), pbs_statjob(3B), 
pbs_statque(3B), pbs_statserver(3B), pbs_submit(3B), pbs_terminate(3B),
pbs_server(8B),
and the PBS Professional Programmer's Guide
.SH DIAGNOSTICS
When the connection to batch server
has been successfully created, the routine will return a connection
identifier which is positive.
Otherwise, a negative value is returned.  The error number is set
in pbs_errno.