Overview of named pipes with ABL

Named pipes provide a general exchange mechanism for text data, and there is no practical limit to the types of data you can exchange using them. Any data you can access as a character string within ABL, you can read or write to a named pipe. For example, you can use named pipes to issue SQL requests to an OpenEdge session from within a spreadsheet program and receive the resulting data in the spreadsheet. As such, you can use named pipes to implement some of the capabilities provided by ABL Host Language Call Interface (HLC).

The following figure shows a typical named pipe scenario.

The message handler procedure acts as a server for a non-OpenEdge application acting as requestor. The server reads each incoming request, processes it, and returns the results through a second named pipe. The messages can contain SQL statements, ABL statements, procedure names, or anything that your message handler procedure can manage.