Re: [Printing-architecture] names of paper sizes

Michael Sweet <[email protected]> Wed, 17 May 2023 06:52:34 -0400

Newsgroups	dev.linux.lists.printing-architecture
Message-ID	<[email protected]>

Mignon,

> On May 14, 2023, at 6:04 PM, Mignon Pelletier <[email protected]> wrote:
> 
> I'm confused about the many names that a paper size can have.
> 
> If I query my DYMO LabelWriter 450 Turbo with code like this:
> 
>         ipp_attribute_t *media =
>             cupsFindDestSupported(CUPS_HTTP_DEFAULT, dest, info,
>                                   CUPS_MEDIA);
>         int i, count = ippGetCount(media);
> 
>         puts("media supported:");
>         for (i = 0; i < count; i ++)
>             printf("  %s\n", ippGetString(media, i, NULL));
> 
> Then I get names like this:
> 
>   custom_54.19x22.27mm_54.19x22.27mm
>   custom_25.4x54.02mm_25.4x54.02mm
>   custom_1x1in_1x1in
>   custom_2.25x1.25in_2.25x1.25in
>   custom_0.75x2in_0.75x2in
>   custom_41.32x88.9mm_41.32x88.9mm
> 
> However, if I run "lpoptions -p LabelWriter-450-Turbo -l", I get names like this:
> 
> PageSize/Media Size: w154h64 w72h154 w72h72 w162h90 w54h144 w118h252
> w167h188 w79h252 w167h252 *w167h288 w154h198 w82h248 w154h64.1
> w79h252.1 w102h252 w154h286 w154h198.1 w54h424 w131h221 w57h248

Correct.  The names you get via IPP are PWG self-describing media size names, while the names reported by lpoptions are the Adobe PPD media size names (a much older "standard").  Both are accepted by the current version of CUPS but going forward only PWG media size names will work.

> ...
> 1) Where are the names reported by cupsFindDestSupported() coming from?

From cupsd, which converts the PPD names to PWG names.  Localization information is placed in a separate .strings file for the queue that can be queried by the application.

> 2) How can I obtain the human-readable names, such as "30330 Return Address", preferably without using any deprecated APIs?

The cupsLocalizeDestMedia function is provided for this since CUPS 2.0.

________________________
Michael Sweet

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