Note: Programming skills may be required to understand the following section.

Developers may take advantage of the programmatic interface to the Georgia SoftWorks SSH2/Telnet Server for Windows. Programmatic, language independent access to the SSH2/Telnet Server allows developers to write an application that (when run under the SSH2/Telnet Server environment) takes control of its input and/or output from/to the client. This can be utilized to create a custom or highly specialized communications application. The SSH2/Telnet Server still maintains critical functionality such as logon, security, application launch and termination. Normally the application before it terminates will release control to the SSH2/Telnet server.

SSH2/Telnet Server communicates with the client through a WINSOCK socket. A protocol/mechanism is provided that allows a custom application to take and release control of the socket. Objects involved in taking and releasing control of the socket are passed through environment variables as are described below.

• GWTN_HSOCKET - This environment variable holds the value of the handle of the open socket. Note: Never close or otherwise destroy the socket.
• GWTN_HSOCKET - This environment variable holds the value of the handle of the open socket. Note: Never close or otherwise destroy the socket.
• GWTN_GET_I - This environment variable holds the name of the WIN32 event that when signaled notifies the SSH2/Telnet server that the custom application wants to take control of the input from the client.
• GWTN_RLS_I - This environment variable holds the name of the WIN32 event that when signaled notifies the SSH2/Telnet server that the custom application wants to release control of the input from the client.
• GWTN_GET_O - This environment variable holds the name of the WIN32 event that when signaled notifies the SSH2/Telnet server that the custom application wants to take control of the output to the client.
• GWTN_RLS_O - This environment variable holds the name of the WIN32 event that when signaled notifies the SSH2/Telnet server that the custom application wants to release control of the output to the client<
• GWTN_ACK - - This environment variable holds the name of the WIN32 event that when signaled notifies the custom application that the request is granted.

Note1: All of the above mentioned events are autoreset events.

Note2: The above environment variables are automatically injected into the session's environment and will vary from session to session. Please do not attempt to modify those variables or set them in the autoexec files or Control Panel/System/Environment.

Please see the file interface.c included on the installation disks for a code sample. interface.c contains a short program that takes control of the input and output and echoes characters to the client until a lowercase q is encountered