DCL to UNIX shell

Based on the experience acquired in the several VMS-to-UNIX migration projects, Software Resources International developed a flexible and sophisticated migration technology that guarantees an automated native migration of VMS applications to the UNIX shell environment. This technology does not require substantial manual work efforts since no manual conversion or redesign of the DCL code is involved. The automated conversion approach has many advantages over an emulation of the DCL environment on UNIX, including a complete migration of the VMS application to the UNIX environment.

The conversion process of a DCL command procedure comprises of two parts. First, the tool "DCL Converter" processes the command procedure and generates the shell script. Most of the script's code is fully converted during this phase. Second, the rest of the command procedure is converted manually. The converter creates comment lines in the resultant shell script that contain the original DCL command(s) and line numbers referring to the source file. This phase is required only for command procedures that contain some rarely used constructions, unsupported command qualifiers and other OpenVMS/DCL features that are hard to support in an automatic converter and require reengineering. The converter informs the user whether the script requires manual actions or not.

The "DCL Converter" is a tool that takes a syntactically correct DCL command procedure as input and produces one or both of the following outputs:

  • A UNIX shell script, which contains equivalents for the most of the command procedure's constructions.
  • A summary overview of OpenVMS features, utilized by the source command procedure, and the list of emulation environment commands, required for the proper execution of resultant shell scripts.

Produced UNIX shell scripts are not intended to run standalone; instead, they should be running in a special environment that emulates concepts having no direct analog in non-VMS systems: logical names, OpenVMS processes and images, file versions, etc. The target platform for automatically converted scripts is Korn shell.

Please contact SRI for documentation or more information.