[Info-vax] SEARCH ''

[Stephen Hoffman]

On 2022-01-18 17:26:06 +0000, hb said:

> On 1/18/22 16:52, Stephen Hoffman wrote:
>> $ search x.com "'" + "'"
> 
> SEARCH (or DCL - which seems more likely) uses "+" as a list separator, 
> so the above command is the same as
> search x.com "'" , "'"
> That is, it finds single quotes.

Yeah, I see that now.

I'd forgotten how limited DCL was.

Ah, well.

$ pipe x="'" + "'" | search x.com &x
$ write sys$output "Page size: ''ps'"


> 
>> grep or find or other tools will work here too, when those are 
>> installed and available.
>> 
>> DCL doesn't have an equivalent to the backslash 
>> escape-the-next-character syntax present in some other contexts.
>> 
> 
> Using grep on *nix for this search is straight forward: grep "''" x.com
> On VMS it's not that obvious: grep "[']\{2\}" x.com
> but there may be an easier way to do that, which I missed.

Works the same.

$ run gnv$gnu:[bin]bash
bash$ grep "''" x.com
$ write sys$output "Page size: ''ps'"
bash$

That avoids using DCL input processing, which avoids the DCL symbol 
substitution.

Can't say I find DCL particularly competitive for text-processing 
tasks, though it is available in the default install.

One of the arguable advantages of DCL over most shells is the 
default-fail error handling. Most shells have to request that. And set 
-e is its own fine mess in bash. Though trap is ~close to ON, and a bit 
more flexible.



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