DCL, or the Digital Command Language, is the default command line interpreter for OpenVMS systems. It can be used to interact with OpenVMS systems on the command line and write command procedures (scripts).
See Command Line Interpreter for more information on DCL.
Command verbs and symbols in DCL can be abbreviated to the minimum number of characters that make the command unique: for example, as long as there is no other command that starts with the same letter, a command can be abbreviated to one character. Usually, however, it takes 2-4 letters to specify a command unambiguously.
DCL only looks at the first 4 characters of a command verb.
When processing a command line, DCL:
- translates all characters to uppercase
- removes multiple spaces, leading and trailing spaces
- removes comments (whatever starts with an exclamation point(!))
Normalization also applies to filenames if the process's parse style is set to TRADITIONAL. Extended file specifications (uppercase letters, extended character set) available for ODS-5 disks can be entered when the parse style is set to EXTENDED with the SET PROCESS/PARSE_STYLE=EXTENDED command.
Information in double quotes (such as equivalence strings, search queries, and multi-word qualifier values) is not subject to normalization.
In DCL scripts, all command lines including comment lines need to be preceded with a dollar sign ($). All lines not preceded with a dollar sign are considered to be data lines for the previous command.