$Sock Conn - Revision history

JALWiccan: Automatically generated page update

2018-09-21T00:00:32Z

Automatically generated page update

← Older revision		Revision as of 00:00, 21 September 2018
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	{{DISPLAYTITLE:$Sock_Conn}}		{{DISPLAYTITLE:$Sock_Conn}}
	<span class="pageSubtitle">Connect to remote using CLSOCK port</span>		<span class="pageSubtitle">Connect to remote using CLSOCK port</span>
	<p class="warn"><b>Note: </b>~~Most Sirius~~ $functions have been deprecated in favor of Object Oriented		<p class="warn"><b>Note: </b>Many $functions have been deprecated in favor of Object Oriented
	methods. The OO equivalent for <var>$Sock_Conn</var> is the <var>Socket</var> class <var>[[New (Socket constructor)\|New]]</var> method.</p>		methods. The OO equivalent for <var>$Sock_Conn</var> is the <var>Socket</var> class <var>[[New (Socket constructor)\|New]]</var> method.</p>
	[[Category: Janus Sockets $functions]]		[[Category: Janus Sockets $functions]]

JAL: clarify error code

2015-12-08T21:19:48Z

clarify error code

← Older revision		Revision as of 21:19, 8 December 2015
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	<table>		<table>
	<tr class="head"><th>Code</th><th>Meaning</th></tr>		<tr class="head"><th>Code</th>
			<th>Meaning</th></tr>

	<tr><td>0</td>		<tr><td>0</td>
	<td>Communications was successful.</td></tr>		<td>Communications was successful.</td></tr>

	<tr><td>100</td>		<tr><td>100</td>
	<td>The format of the response from the server was invalid.</td></tr>		<td>The format of the response from the server was invalid.</td></tr>

	<tr><td>101</td>		<tr><td>101</td>
	<td>A <var>Get</var> operation exceeded its [[Timeout (HttpRequest property)\|timeout]] value.</td></tr>		<td>A <var>Get</var> operation exceeded its [[Timeout (HttpRequest property)\|timeout]] value.</td></tr>

	<tr><td>102</td>		<tr><td>102</td>
	<td>The connection was closed before the complete response was received.</td></tr>		<td>The connection was closed before the complete response was received.</td></tr>

	<tr><td>-100</td>		<tr><td>-100</td>
	<td>No free socket numbers for user.</td></tr>		<td>No free socket numbers for user.</td></tr>

	<tr><td>-101</td>		<tr><td>-101</td>
	<td>Remote host name or IP address missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>		<td>Remote host name or IP address missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>

	<tr><td>-102</td>		<tr><td>-102</td>
	<td>Remote port number missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>		<td>Remote port number missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>

	<tr><td>-103</td>		<tr><td>-103</td>
	<td><var>CLSOCK</var> port not defined or not started.</td></tr>		<td><var>CLSOCK</var> port not defined or not started.</td></tr>

	<tr><td>-104</td>		<tr><td>-104</td>
	<td>All ports on specified <var>CLSOCK</var> port are busy.</td></tr>		<td>All ports on specified <var>CLSOCK</var> port are busy.</td></tr>

	<tr><td>-105</td>		<tr><td>-105</td>
	<td>Insufficient virtual storage.</td></tr>		<td>Insufficient virtual storage.</td></tr>

	<tr><td>-106</td>		<tr><td>-106</td>
	<td>Maximum connections exceeded.</td></tr>		<td>Maximum connections exceeded.</td></tr>

	<tr><td>-107</td>		<tr><td>-107</td>
	<td>Couldn't resolve remote host.</td></tr>		<td>Couldn't resolve remote host.</td></tr>

	<tr><td>-108</td>		<tr><td>-108</td>
	<td>Remote port not responding.</td></tr>		<td>Remote port not responding.</td></tr>

	<tr><td>-109</td>		<tr><td>-109</td>
	<td>Already have <var>[[SOCKPMAX]]</var> sockets open on this <var>CLSOCK</var> port.</td></tr>		<td>Already have <var>[[SOCKPMAX]]</var> sockets open on this <var>CLSOCK</var> port.</td></tr>

	<tr><td>-110</td>		<tr><td>-110</td>
	<td>SSL/NOSSL setting mismatch.</td></tr>		<td>SSL/NOSSL setting mismatch.</td></tr>

	<tr><td>-111</td>		<tr><td>-111</td>
	<td>SSL handshake error.</td></tr>		<td>SSL handshake error.</td></tr>

	<tr><td>-112</td>		<tr><td>-112</td>
	<td>Access to <var>CLSOCK</var> port not enabled by <var>[[JANUS WEB ALLOW\|ALLOW]]</var> rule.</td></tr>		<td>Access to <var>CLSOCK</var> port not enabled by <var>[[JANUS WEB ALLOW\|ALLOW]]</var> rule.</td></tr>

	<tr><td>-149</td>		<tr><td>-149</td>
	<td>Other error during connection.</td></tr>		<td>Other error during connection attempt which prevents establishment of the connection.</td></tr>
	</table>		</table>

	==Usage notes==		==Usage notes==
	<ul>		<ul>
	<li>$Sock_xxx functions that encounter an "unusable" socket can ordinarily be handled by a jump to an <var>ONRESET</var> label, by request cancellation, or by continuation of the request at the next statement with an error return code. <var>$Sock_Conn</var>, however, always continues execution with the next statement. It does not have a socket number argument, and it cannot encounter a reset socket. You must check the error return code: if it is negative and you try to use it in a subsequent $Sock_xxx call, the request will be cancelled at that time. <li>When <var>$Sock_Conn</var> detects an error, it also issues an error message to the user. If you want to suppress this, and the <var>APSY</var> facility for suppressing error messages is not appropriate for your application, you can use the <var>[[$Resetn]]</var> function to set the <var>MSGCTL</var> user parameter to 4.		<li>$Sock_xxx functions that encounter an "unusable" socket can ordinarily be handled by a jump to an <var>ONRESET</var> label, by request cancellation, or by continuation of the request at the next statement with an error return code. <var>$Sock_Conn</var>, however, always continues execution with the next statement. It does not have a socket number argument, and it cannot encounter a reset socket. You must check the error return code: if it is negative and you try to use it in a subsequent $Sock_xxx call, the request will be cancelled at that time.
			</li>

			<li>When <var>$Sock_Conn</var> detects an error, it also issues an error message to the user. If you want to suppress this, and the <var>APSY</var> facility for suppressing error messages is not appropriate for your application, you can use the <var>[[$Resetn]]</var> function to set the <var>MSGCTL</var> user parameter to 4. </li>

	<li><var>$Sock_Conn</var> initiates a connection to a remote port over a client socket port. If the remote host and port were specified on the client socket port definition, they don't have to be specified in the function call.		<li><var>$Sock_Conn</var> initiates a connection to a remote port over a client socket port. If the remote host and port were specified on the client socket port definition, they don't have to be specified in the function call.
	In the following example, because the port definition specifies that all client requests on port <code>SOCKEM</code> will go to port 80 at host IP address <code>198.242.244.47</code>, specifying the destination on the function call is superfluous. <code>%num</code> contains either a positive number identifying the socket number or a negative number identifying the type of error received during the attempt to establish a new socket connection. A negative number indicates an error condition, and processing is routed to an error-handling subroutine.		<p>
			In the following example, because the port definition specifies that all client requests on port <code>SOCKEM</code> will go to port 80 at host IP address <code>198.242.244.47</code>, specifying the destination on the function call is superfluous. <code>%num</code> contains either a positive number identifying the socket number or a negative number identifying the type of error received during the attempt to establish a new socket connection. A negative number indicates an error condition, and processing is routed to an error-handling subroutine. </p>
	<p class="code">JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE 198.242.244.47 80		<p class="code">JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE 198.242.244.47 80
	Begin		Begin
Line 94:		Line 118:
	Call PROCESS_SOCKET_ERROR		Call PROCESS_SOCKET_ERROR
	End If ... </p>		End If ... </p>
	In the example below, the port is defined to accept client requests to any remote port. The <var>$Sock_Conn</var> function specifies a connection to the default web port (80) at a well-known satirical news provider.		<p>
			In the example below, the port is defined to accept client requests to any remote port. The <var>$Sock_Conn</var> function specifies a connection to the default web port (80) at a well-known satirical news provider. </p>
	<p class="code">* Define the client sockets port.		<p class="code">* Define the client sockets port.
	JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE * *		JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE * *
Line 102:		Line 127:
	If %num Lt 0 Then		If %num Lt 0 Then
	Call PROCESS_SOCKET_ERROR		Call PROCESS_SOCKET_ERROR
	End If ... </p>		End If ... </p> </li>

	<li>The <code>FINCLOSE</code> option is useful in situations where <code>FIN</code> is as good as <code>RESET</code> for rendering a connection unusable, and where it's important to know that <code>FIN</code> has been sent to avoid wasted processing or even a hung connection.		<li>The <code>FINCLOSE</code> option is useful in situations where <code>FIN</code> is as good as <code>RESET</code> for rendering a connection unusable, and where it's important to know that <code>FIN</code> has been sent to avoid wasted processing or even a hung connection.
			<p>
	For example, an appropriate occasion for <code>FINCLOSE</code> is a <var class="product">Janus Sockets</var> application communicating with a web server that is using a keep-alive facility (multiple requests over the same TCP/IP connection). Such a web server could close the connection between any pair of requests, and probably would use <code>FIN</code>. Without <code>FINCLOSE</code>, the Janus thread that connected to the web server would remain in-use until the <var class="product">Janus Sockets</var> application tried to receive data on the connection and so noticed the closed connection. </ul>		For example, an appropriate occasion for <code>FINCLOSE</code> is a <var class="product">Janus Sockets</var> application communicating with a web server that is using a keep-alive facility (multiple requests over the same TCP/IP connection). Such a web server could close the connection between any pair of requests, and probably would use <code>FIN</code>. Without <code>FINCLOSE</code>, the Janus thread that connected to the web server would remain in-use until the <var class="product">Janus Sockets</var> application tried to receive data on the connection and so noticed the closed connection. </p></li>
			</ul>

JAL: /* $Sock_Conn return values */

2013-10-21T19:26:27Z

$Sock_Conn return values

← Older revision		Revision as of 19:26, 21 October 2013
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	<table>		<table>
	<tr class="head"><th~~><i~~>Code~~</i>~~</th><th~~><i~~>Meaning~~</i>~~</th></tr>		<tr class="head"><th>Code</th><th>Meaning</th></tr>
	<tr><td>0</td>		<tr><td>0</td>
	<td>Communications was successful.</td></tr>		<td>Communications was successful.</td></tr>

JAL: /* $Sock_Conn return values */

2013-10-21T19:25:55Z

$Sock_Conn return values

← Older revision		Revision as of 19:25, 21 October 2013
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	<table>		<table>
	<tr><th><i>Code</i></th><th><i>Meaning</i></th></tr>		<tr class="head"><th><i>Code</i></th><th><i>Meaning</i></th></tr>
	<tr><td>0</td>		<tr><td>0</td>
	<td>Communications was successful.</td></tr>		<td>Communications was successful.</td></tr>

JAL at 21:42, 23 July 2013

2013-07-23T21:42:09Z

← Older revision		Revision as of 21:42, 23 July 2013
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	<span class="pageSubtitle">Connect to remote using CLSOCK port</span>		<span class="pageSubtitle">Connect to remote using CLSOCK port</span>
	<p class="warn"><b>Note: </b>Most Sirius $functions have been deprecated in favor of Object Oriented		<p class="warn"><b>Note: </b>Most Sirius $functions have been deprecated in favor of Object Oriented
	methods. ~~There is currently no direct~~ OO equivalent for ~~this~~ $~~function~~.</p>		methods. The OO equivalent for <var>$Sock_Conn</var> is the <var>Socket</var> class <var>[[New (Socket constructor)\|New]]</var> method.</p>
	[[Category: Janus Sockets $functions]]		[[Category: Janus Sockets $functions]]

JALWiccan: Automatically generated page update

2013-07-19T18:59:24Z

Automatically generated page update

← Older revision		Revision as of 18:59, 19 July 2013
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	{{DISPLAYTITLE:$Sock_Conn}}		{{DISPLAYTITLE:$Sock_Conn}}
	<span class="pageSubtitle">Connect to remote using CLSOCK port</span>		<span class="pageSubtitle">Connect to remote using CLSOCK port</span>
	<p class="~~warning~~">Most Sirius $functions have been deprecated in favor of Object Oriented		<p class="warn"><b>Note: </b>Most Sirius $functions have been deprecated in favor of Object Oriented
	methods. There is currently no direct OO equivalent for this $function.</p>		methods. There is currently no direct OO equivalent for this $function.</p>
	[[Category: Janus Sockets $functions]]		[[Category: Janus Sockets $functions]]

JAL2 at 03:18, 20 January 2012

2012-01-20T03:18:39Z

← Older revision		Revision as of 03:18, 20 January 2012
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	<tr><th><var>SSL</var> </th>		<tr><th><var>SSL</var> </th>
	<td>Use SSL (Secure Sockets Layer) encryption over the connection (see <var>[[SSL (JANUS DEFINE parameter)\|SSL]]</var>, and see the <i>[http://www.sirius-software.com/maint/download/jansslr.pdf Janus Network Security Reference Manual]</i>). Setting <code>SSL</code> here is meaningful only if the port definition includes the <var>SSL</var> and <var>[[SSLOPT (JANUS DEFINE parameter)\|SSLOPT]]</var> parameters (in which case, by default, SSL is '''not''' used unless the socket connection explicitly requests it).		<td>Use SSL (Secure Sockets Layer) encryption over the connection (see <var>[[SSL (JANUS DEFINE parameter)\|SSL]]</var>, and see the <i>[http://www.sirius-software.com/maint/download/jansslr.pdf Janus Network Security Reference Manual]</i>). Setting <code>SSL</code> here is meaningful only if the port definition includes the <var>SSL</var> and <var>[[SSLOPT (JANUS DEFINE parameter)\|SSLOPT]]</var> parameters (in which case, by default, SSL is '''not''' used unless the socket connection explicitly requests it).
			<p>
	Setting <code>SSL</code> here is redundant if the port definition includes <var>SSL</var> but not <var>SSLOPT</var>, and setting it is invalid if the port definition excludes <var>SSL</var>. </td></tr>		Setting <code>SSL</code> here is redundant if the port definition includes <var>SSL</var> but not <var>SSLOPT</var>, and setting it is invalid if the port definition excludes <var>SSL</var>. </p></td></tr>
	<tr><th><var>NOSSL</var></th>		<tr><th><var>NOSSL</var></th>
	<td>Do not use SSL over the connection. This setting is valid only if the port definition includes the <var>SSLOPT</var> parameter. </td></tr>		<td>Do not use SSL over the connection. This setting is valid only if the port definition includes the <var>SSLOPT</var> parameter. </td></tr>

JAL2: /* Syntax */

2012-01-20T03:15:27Z

Syntax

← Older revision		Revision as of 03:15, 20 January 2012
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	==Syntax==		==Syntax==
	<p class="syntax"><span class="term">%num</span> <span class="literal">= $Sock_Conn(</span><span class="term">socketPortName</span><span class="literal">,</span> <span class="term">remoteHost</span><span class="literal">,</span> <span class="term">remotePort</span><span class="literal">,</span> <span class="term">options</span><span class="literal">)</span> </p>		<p class="syntax"><span class="term">%num</span> <span class="literal">= $Sock_Conn(</span><span class="term">socketPortName</span><span class="literal">,</span> <span class="term">remoteHost</span><span class="literal">,</span> <span class="term">remotePort</span><span class="literal">,</span> <span class="squareb">[</span><span class="term">options</span><span class="squareb">]</span><span class="literal">)</span> </p>

	===Syntax terms===		===Syntax terms===
Line 26:		Line 26:
	<table class="syntaxTable">		<table class="syntaxTable">
	<tr><th><var>SSL</var> </th>		<tr><th><var>SSL</var> </th>
	<td>Use SSL (Secure Sockets Layer) encryption over the connection (see <var>[[SSL (JANUS DEFINE parameter)\|SSL]]</var>, and see the [http://www.sirius-software.com/maint/download/jansslr.pdf Janus Network Security Reference Manual]). Setting <code>SSL</code> here is meaningful only if the port definition includes the <var>SSL</var> and <var>[[SSLOPT (JANUS DEFINE parameter)\|SSLOPT]]</var> parameters (in which case, by default, SSL is '''not''' used unless the socket connection explicitly requests it).		<td>Use SSL (Secure Sockets Layer) encryption over the connection (see <var>[[SSL (JANUS DEFINE parameter)\|SSL]]</var>, and see the <i>[http://www.sirius-software.com/maint/download/jansslr.pdf Janus Network Security Reference Manual]</i>). Setting <code>SSL</code> here is meaningful only if the port definition includes the <var>SSL</var> and <var>[[SSLOPT (JANUS DEFINE parameter)\|SSLOPT]]</var> parameters (in which case, by default, SSL is '''not''' used unless the socket connection explicitly requests it).

	Setting <code>SSL</code> here is redundant if the port definition includes <var>SSL</var> but not <var>SSLOPT</var>, and setting it is invalid if the port definition excludes <var>SSL</var>. </td></tr>		Setting <code>SSL</code> here is redundant if the port definition includes <var>SSL</var> but not <var>SSLOPT</var>, and setting it is invalid if the port definition excludes <var>SSL</var>. </td></tr>
Line 80:		Line 80:
	<tr><td>-149</td>		<tr><td>-149</td>
	<td>Other error during connection.</td></tr>		<td>Other error during connection.</td></tr>
	</table>		</table>

	==Usage notes==		==Usage notes==

Admin: 1 revision

2012-01-20T02:53:45Z

1 revision

← Older revision	Revision as of 02:53, 20 January 2012
(No difference)

JAL at 21:04, 19 January 2012

2012-01-19T21:04:54Z

New page

{{DISPLAYTITLE:$Sock_Conn}}
Connect to remote using CLSOCK port
Most Sirius $functions have been deprecated in favor of Object Oriented
methods. There is currently no direct OO equivalent for this $function.
[[Category: Janus Sockets $functions]]

<var>$Sock_Conn</var> creates a connection to a remote host using a Janus
client socket port.

==Syntax==
%num = $Sock_Conn(socketPortName, remoteHost, remotePort, options) 

===Syntax terms===
<table class="syntaxTable">
<tr><th>%num</th>
<td>An integer socket identifier or an error code. </td></tr>
<tr><th>socketPortName</th>
<td>The client socket port name. The <var class="term">socketPortName</var> default is the <var>[[MASTER (JANUS DEFINE parameter)|MASTER]]</var> port, if any is defined. However, if you omit <var class="term">socketPortName</var> and no <var>MASTER</var> port is defined, the request is canceled. </td></tr>
<tr><th>remoteHost</th>
<td>The remote host name or IP address. This argument is optional or may be the null string if the remote host or remote IP address is fully specified on the port definition <var>[[REMOTE (JANUS DEFINE parameter)|REMOTE]]</var> clause.
If <var class="term">remoteHost</var> is specified and is not the null string, it must match the remote host specified explicitly or indicated by a pattern on the port definition. If an asterisk (*) was specified for the remote host on the port definition, <var class="term">remoteHost</var> must be specified. The remote host may also be restricted by <var>[[JANUS_CLSOCK#JANUS_CLSOCK_ALLOW|JANUS CLSOCK ALLOW]]</var> rules. </td></tr>
<tr><th>remotePort</th>
<td>The port number on the remote host to which the socket will connect. If a port number was specified on the <var>REMOTE</var> clause of the port definition, this argument can be either the matching number or -1, or it can be omitted. If an asterisk (*) was specified for the remote port on the port definition, <var class="term">remotePort</var> must be specified. The port number may also be restricted by <var>[[JANUS_CLSOCK#JANUS_CLSOCK_ALLOW|JANUS CLSOCK ALLOW]]</var> rules. </td></tr>
<tr><th>options</th>
<td>An option string that can be used to invoke socket-specific processing that is not already explicitly specified on the <var>[[JANUS DEFINE]]</var> command for the port. The argument string may contain one or two options, selected from the two pairs of alternatives below. If the argument string is omitted, the option defaults depend on the <var>[[JANUS DEFINE#type|CLSOCK]]</var> port definition. If the argument string contains an option that conflicts with the port definition, the request is canceled.
<table class="syntaxTable">
<tr><th><var>SSL</var> </th>
<td>Use SSL (Secure Sockets Layer) encryption over the connection (see <var>[[SSL (JANUS DEFINE parameter)|SSL]]</var>, and see the [http://www.sirius-software.com/maint/download/jansslr.pdf Janus Network Security Reference Manual]). Setting <code>SSL</code> here is meaningful only if the port definition includes the <var>SSL</var> and <var>[[SSLOPT (JANUS DEFINE parameter)|SSLOPT]]</var> parameters (in which case, by default, SSL is '''not''' used unless the socket connection explicitly requests it).

Setting <code>SSL</code> here is redundant if the port definition includes <var>SSL</var> but not <var>SSLOPT</var>, and setting it is invalid if the port definition excludes <var>SSL</var>. </td></tr>
<tr><th><var>NOSSL</var></th>
<td>Do not use SSL over the connection. This setting is valid only if the port definition includes the <var>SSLOPT</var> parameter. </td></tr>
<tr><th><var>FINCLOSE</var></th>
<td>If the remote host closes the connection, even if it does so "cleanly" (that is, with <code>FIN</code> rather than <code>RESET</code>), <var class="product">Janus Sockets</var> closes the connection immediately. This setting avoids wasted processing or even a hung connection in a situation(like a keep-alive facility) where a remote application uses a <code>FIN</code> to close a connection with a request. </td></tr>
<tr><th><var>NOFINCLOSE</var>
</th><td>Do not use <var>FINCLOSE</var> processing for this connection. </td></tr>
</table>
</table>

===$Sock_Conn return values===
The number returned from <var>$Sock_Conn</var> is a positive value which is used as the
identifier of the successfully connected socket, or otherwise it is an error code as shown below:

<table>
<tr><th>Code</th><th>Meaning</th></tr>
<tr><td>0</td>
<td>Communications was successful.</td></tr>
<tr><td>100</td>
<td>The format of the response from the server was invalid.</td></tr>
<tr><td>101</td>
<td>A <var>Get</var> operation exceeded its [[Timeout (HttpRequest property)|timeout]] value.</td></tr>
<tr><td>102</td>
<td>The connection was closed before the complete response was received.</td></tr>
<tr><td>-100</td>
<td>No free socket numbers for user.</td></tr>
<tr><td>-101</td>
<td>Remote host name or IP address missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>
<tr><td>-102</td>
<td>Remote port number missing or mismatch with <var>CLSOCK</var> port definition.</td></tr>
<tr><td>-103</td>
<td><var>CLSOCK</var> port not defined or not started.</td></tr>
<tr><td>-104</td>
<td>All ports on specified <var>CLSOCK</var> port are busy.</td></tr>
<tr><td>-105</td>
<td>Insufficient virtual storage.</td></tr>
<tr><td>-106</td>
<td>Maximum connections exceeded.</td></tr>
<tr><td>-107</td>
<td>Couldn't resolve remote host.</td></tr>
<tr><td>-108</td>
<td>Remote port not responding.</td></tr>
<tr><td>-109</td>
<td>Already have <var>[[SOCKPMAX]]</var> sockets open on this <var>CLSOCK</var> port.</td></tr>
<tr><td>-110</td>
<td>SSL/NOSSL setting mismatch.</td></tr>
<tr><td>-111</td>
<td>SSL handshake error.</td></tr>
<tr><td>-112</td>
<td>Access to <var>CLSOCK</var> port not enabled by <var>[[JANUS WEB ALLOW|ALLOW]]</var> rule.</td></tr>
<tr><td>-149</td>
<td>Other error during connection.</td></tr>
</table>

==Usage notes==
<ul>
<li>$Sock_xxx functions that encounter an "unusable" socket can ordinarily be handled by a jump to an <var>ONRESET</var> label, by request cancellation, or by continuation of the request at the next statement with an error return code. <var>$Sock_Conn</var>, however, always continues execution with the next statement. It does not have a socket number argument, and it cannot encounter a reset socket. You must check the error return code: if it is negative and you try to use it in a subsequent $Sock_xxx call, the request will be cancelled at that time. <li>When <var>$Sock_Conn</var> detects an error, it also issues an error message to the user. If you want to suppress this, and the <var>APSY</var> facility for suppressing error messages is not appropriate for your application, you can use the <var>[[$Resetn]]</var> function to set the <var>MSGCTL</var> user parameter to 4.
<li><var>$Sock_Conn</var> initiates a connection to a remote port over a client socket port. If the remote host and port were specified on the client socket port definition, they don't have to be specified in the function call.
In the following example, because the port definition specifies that all client requests on port <code>SOCKEM</code> will go to port 80 at host IP address <code>198.242.244.47</code>, specifying the destination on the function call is superfluous. <code>%num</code> contains either a positive number identifying the socket number or a negative number identifying the type of error received during the attempt to establish a new socket connection. A negative number indicates an error condition, and processing is routed to an error-handling subroutine.
JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE 198.242.244.47 80
Begin
...
%num = $Sock_Conn('SOCKEM')
If %num Lt 0 Then
Call PROCESS_SOCKET_ERROR
End If ... 
In the example below, the port is defined to accept client requests to any remote port. The <var>$Sock_Conn</var> function specifies a connection to the default web port (80) at a well-known satirical news provider.
* Define the client sockets port.
JANUS DEFINE SOCKEM * CLSOCK 5 REMOTE * *
Begin
...
%num = $Sock_Conn('SOCKEM', 'www.theonion.com', 80)
If %num Lt 0 Then
Call PROCESS_SOCKET_ERROR
End If ... 
<li>The <code>FINCLOSE</code> option is useful in situations where <code>FIN</code> is as good as <code>RESET</code> for rendering a connection unusable, and where it's important to know that <code>FIN</code> has been sent to avoid wasted processing or even a hung connection.

For example, an appropriate occasion for <code>FINCLOSE</code> is a <var class="product">Janus Sockets</var> application communicating with a web server that is using a keep-alive facility (multiple requests over the same TCP/IP connection). Such a web server could close the connection between any pair of requests, and probably would use <code>FIN</code>. Without <code>FINCLOSE</code>, the Janus thread that connected to the web server would remain in-use until the <var class="product">Janus Sockets</var> application tried to receive data on the connection and so noticed the closed connection. </ul>