Janus Sockets $functions

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The User Language sockets API is implemented as the Janus Sockets $function set. The Janus SOAP Socket, HTTP Helper, Email, and LDAP objects and methods are alternatives that generalize the Janus Sockets $functions and are designed to be easier to use. These $functions and object methods provide User Language programs with the ability to receive and send using socket ports.

This topic is primarily concerned with how to use the individual $functions, though much of its text applies as well to the Socket object methods that are largely analogous to the $functions.

There are a few restrictions on the order in which the Janus Sockets $functions are used: for example, a socket port must be connected before data is sent using it, and data may not be sent after the FIN indicator is sent. For more information about Janus Sockets programming, see Janus Sockets User Language coding considerations.

Sample programs using $functions are included in Sample Janus Sockets programs and in the JANUS file distributed with this product.

Janus Sockets $function summary

The Janus Sockets SOUL $functions for communicating with remote hosts over TCP/IP are listed below and described individually in sections that follow:

$Sock_Capture Change print capture setting
$Sock_Cert_Info Get value of entity in partner's certificate
$Sock_Cert_Levels Get number of levels in partner's certificate
$Sock_Close Terminate sending and receiving of data on, and remove from use, one or all Janus Sockets connection(s)
$Sock_Conn Create connection to remote host using CLSOCK port
$Sock_ErrInfo Get info about last Janus Sockets error
$Sock_Info Get info about socket
$Sock_Num Get selected socket numbers
$Sock_OnReset Set label to handle RESET conditions
$Sock_Recv Receive string based on count
$Sock_RecvPrs Receive parsed string
$Sock_Send Send string
$Sock_SendLn Send string followed by LINEND
$Sock_Set Change parameter or setting on one or all sockets
$Sock_SSL_On Switch to SSL processing on a socket
$Sock_Tran_In Translate string, from character set of remote, to local internal character set ("EBCDIC")
$Sock_Tran_Out Translate string, from local internal character set ("EBCDIC"), to character set of remote
$Sock_URL_Encode Encode special characters into the URL "% hex hex" format
Print operations In addition to the above list of $functions, data may be sent over a socket as the result of a "print" operation. This is accomplished by the $Sock_Capture function. Note that print operations outside a User Language request can be captured as well, if a capturing socket has the NOCLOSE setting.

For example, the DISPLAY command, and the User Language Print statement and Html statement block are all print operations; if they are invoked while print is captured to one or more sockets, their output lines are sent to the sockets. A print line is sent followed by the socket's current LINEND value, if any. See Print capturing hierarchy and other considerations and Print capturing example.

CALLing Sirius $functions

You can invoke many of the Sirius $functions using a SOUL Call statement instead of assigning the function result to a %variable. For example:

%l = $ListNew $ListAdd(%L, 'Once upon a midnight dreary') $ListAdd(%L, 'As I pondered weak and weary') Call $List_Print(%l)

You can Call such $functions and still test for their return code, if necessary. For example:

Call $List_Print(%l) If $List_Print(%l) Then

This "callability" is an optional approach; it does not replace %variable assignment.

The callable $functions are indicated as such in their individual function descriptions. Typically they are $functions that do more than simply return a value, and the value they return is primarily an indicator of whether the function completed successfully. $ListCnt, for example, is a (non-callable) $function that just returns a value.

See also