In PARSEC VMS classes, we also say that “Error messages are your friends.” But sometimes just the error message text itself doesn't tell you quite enough to fix a command problem.
A little known and infrequently used variant of the HELP command allows you to review help-text specifically for the current or last-occurring DCL error message displayed on your screen – see in particular:
$ HELP HELP /MESSAGE ...
Best shown by example:
$ cp login.txt foo.txt %DCL-W-IVVERB, unrecognized command verb - check validity and spelling \CP\ $ copy login.txt foo.txt %COPY-E-OPENIN, error opening DSA2:[LRICKER]login.txt; as input -RMS-E-FNF, file not found $ help /message OPENIN, error opening 'input-file-spec' as input Facility: Shared by several facilities Explanation: The specified input file cannot be opened. User Action: Make sure the file exists and is accessible, or take action based on an accompanying message.
By default (without a command parameter),
HELP /MESSAGE shows the error-message help for the last/latest/current command. If you want to see help-text for a previous error, be sure to note the error-message “abbreviation string”, whatever follows the
-F- part of the error message, and use that as the parameter for
$ help /message ivverb IVVERB, unrecognized command verb - check validity and spelling Facility: CLI, Command Language Interpreter (DCL) Explanation: The first word in the command is not a valid DCL command or a symbol name equated with a command. The rejected portion of the command is displayed between backslashes. User Action: Check the spelling of the command name or symbol name, then reenter the command.
User Action and
Explanation texts are usually sufficient to figure out what's wrong with the command and how to fix it.