Format of DCL Commands

DCL commands follow a uniform format, separating DCL from most other CLIs. On many other systems, the command line is simply passed in its entirety to the program. Each program performs its own command line processing, resulting in some inconsistencies between the command line formats for different programs.

DCL, on the other hand, performs full command line processing and rejects many invalid commands without the need to invoke the corresponding program. Most OpenVMS programs retrieve command line elements from DCL during execution and never examine the full command line as typed by the user.

Once you understand the general DCL command format, you will be able to apply that experience to OpenVMS programs you have never used before.

For those programs that process their own command lines, DCL does provide a mechanism for passing the command line directly to them (see "Foreign Commands" in Chapter 7, "The User Environment").