About NCL

NCL is a high-level interpretive language integrated into many components to provide a fast, comprehensive, and advanced development tool to implement the specific requirements of an installation. NCL is the vehicle through which your product region is rapidly tailored to the needs of the installation.

NCL is based on free-form statement syntax that can process both system and user-supplied data. Data is maintained in variables, which is manipulated and changed as required.

Collections of NCL statements, which may include system commands, are termed procedures and are stored in partitioned data sets (z/OS) or CMS files (z/VM) called procedure libraries, which is edited and updated while your product region is operational. Each NCL procedure is a separate member within a procedure library.

There is one principal procedure library (or concatenation of libraries) used by your product region. In addition to this system library, individual users under z/OS is allocated an individual procedure library for their own use, as part of the definition of their user ID.

NCL procedures can take many forms. They is a simple collection of comment statements that provide an effective means of online documentation. They is a collection of your product region commands in exactly the same format as entered from a terminal. They is extended to include logical decision making capabilities, the display of full-screen panels and the use of file processing capabilities.

An NCL procedure can call or nest to another procedure to improve modularity.

In addition, certain NCL procedures are reserved for performing special functions such as interfacing to unsolicited messages from VTAM (PPOPROC), intercepting and reacting to other messages sent to the user terminal (MSGPROC), and processing messages destined for the activity logs (LOGPROC).