'\" t
.\"     Title: modbus_tcp_listen
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 11/30/2016
.\"    Manual: Libmodbus Manual
.\"    Source: libmodbus 3.0.6
.\"  Language: English
.\"
.TH "MODBUS_TCP_LISTEN" "3" "11/30/2016" "libmodbus 3\&.0\&.6" "Libmodbus Manual"
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.SH "NAME"
modbus_tcp_listen \- create and listen a TCP Modbus socket
.SH "SYNOPSIS"
.sp
\fBint modbus_tcp_listen(modbus_t *\fR\fB\fIctx\fR\fR\fB, int \fR\fB\fInb_connection\fR\fR\fB);\fR
.SH "DESCRIPTION"
.sp
The \fImodbus_tcp_listen()\fR function shall create a socket and listen for \fInb_connection\fR incoming connections\&.
.SH "RETURN VALUE"
.sp
The \fImodbus_tcp_listen()\fR function shall return a new socket if successful\&. Otherwise it shall return \-1 and set errno\&.
.SH "EXAMPLE"
.sp
For a detailed example, see source file bandwith\-server\-many\-up\&.c provided in tests directory\&.
.sp
.if n \{\
.RS 4
.\}
.nf
\&.\&.\&.

ctx = modbus_new_tcp("127\&.0\&.0\&.1", 502);
if (modbus_connect(ctx) == \-1) {
    fprintf(stderr, "Connection failed: %s\en", modbus_strerror(errno));
    modbus_free(ctx);
    return \-1;
}

/* Handle until 10 established connections */
server_socket = modbus_tcp_listen(ctx, 10);

/* Clear the reference set of socket */
FD_ZERO(&refset);

/* Add the server socket */
FD_SET(server_socket, &refset);

if (select(server_socket + 1, &refset, NULL, NULL, NULL) == \-1) {
}

\&.\&.\&.

close(server_socket);
modbus_free(ctx);
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fBmodbus_tcp_accept\fR(3) \fBmodbus_tcp_pi_accept\fR(3) \fBmodbus_tcp_pi_listen\fR(3)
.SH "AUTHORS"
.sp
The libmodbus documentation was written by St\('ephane Raimbault <\m[blue]\fBstephane\&.raimbault@gmail\&.com\fR\m[]\&\s-2\u[1]\d\s+2>
.SH "NOTES"
.IP " 1." 4
stephane.raimbault@gmail.com
.RS 4
\%mailto:stephane.raimbault@gmail.com
.RE