[Info-vax] Logical names, was: Re: Command Procedure Pipe output to a variable

[Tad Winters]

On 10/10/2021 6:38 AM, David Jones via Info-vax wrote:
> On Sunday, October 10, 2021 at 8:51:26 AM UTC-4, Arne Vajhøj wrote:
>> Logicals make good sense for devices, directories and files.
>>
>> Arne
>
> DCL has 2 commands to create logical names, ASSIGN and DEFINE. The first
> one doesn't get much mention anymore but seems sensible if you have a
> program that reads from 'TAPE1' and writes to 'TAPE2'.


I recall using ASSIGN /MERGE to move a large number of entries from one
queue to another.

I've used logical names to:

- temporarily start sending print jobs to an alternate queue.
- redirect the log file of a batch job to NLA0: when no error occurs.
- point at different data sets, sometimes on different disks, based on
the selection of branch (office) or "site."
- cause the print symbiont to modify the stream of output sent to the
target device.

I'm sure I've used them for other purposes, but it's been so long since
I've done any real development, that those uses escape me.