Work Flow Language: Difference between revisions

Revision as of 20:27, 10 July 2005

Revision as of 13:40, 19 August 2005

Line 1:

'''Work Flow Language''', or '''WFL''' (pronounced wiffle) was developed for the [[B5000]] line of computers and its operating system [[Master Control Program]]. It is still used as the operations language on the [[Unisys]] [[ClearPath/MCP]] range of machines. Developed soon after the B5000, WFL is the ClearPath equivalent of [[JCL]] on other machines and the [[shell scriptsscript]]s of [[Unix]]-style operating systems. Unlike JCL and shell scripts though, WFL is a high-level structured language complete with routines (procedures and functions) with arguments and high-level program control flow instructions. WFL programs are compiled so that they don't fail on statements during the run of a WFL job.

WFL is used for high-level system operations, such as running tasks, moving and copying files, providing high-level recoverability. Thus it is not a general purpose language in that you would not use it to do general computations. You can open and close files to check their attributes for example; however, you cannot read or change their contents in WFL – that you do in a general purpose language, and invoke it as a task from WFL.

WFL has a high-level [[ALGOL]]-like readable syntax. It has none of the low-level assembler-like commands of JCL like //SYSIN DD, etc in order to connect hardware devices and open files for programs. All WFL constructs deal with the high-level abstractions of tasks and files. Parameters are also real HLL parameters, not the $1, $2... style position parameters of shell scripts.

WFL also has an instruction block command which is used to give operators instructions needed to run the current job. These instructions are displayed using the 'IB' operator command.