Hi ,
Thanks Branden for your answer. but it wasn't really what I was looking for.
I found a solution to set the right page length for each ticket.
Like Deri said it cuts after each print job but I just needed to tell how
long each ticket is.
so here is my solution:
the last line of my groff script is:
".tm \\n[nl]"
This shows me the page length in groff units.
For convenience I put it in a footer macro.
Then in a bash script I have this:
size=$(groff -P-p6.5c,7c -z kasticket.groff 2>&1)
size=$(echo "scale=2;$size / 28346 + 0.5" | bc)
groff -P-p${siz}c,7.2c kasticket.groff > kasticket.ps
The first line gets the size from groff with -z option so no other output
is given.
the second converts the units to cm and adds a little bit of margin.
The last line creates the ticket with the right length.
Kind regards,
Wim Stockman
Op vr 9 dec. 2022 om 00:48 schreef Deri <d...@chuzzlewit.myzen.co.uk>:
> On Thursday, 8 December 2022 17:19:49 GMT G. Branden Robinson wrote:
> > Hi Wim,
> >
> > At 2022-12-08T15:51:07+0100, Wim Stockman wrote:
> > > I am making a simple cash register with a ticket printer. and I want
> > > to figure out how I can detect how long my physical paper should be
> > > without cutting some text off. So I can set it for the device. The
> > > width is fixed so that is no issue. Eventually I can run it in some
> > > loop and detect when it stops having more than one page.
> >
> > I reckon I would have a couple of macros that open and close a
> > diversion, then measure against an argument that specifies the limit
> > imposed by the hardware (i.e., length of paper roll remaining).
> >
> > Here's a conceptual sketch.
> >
> > .de StartTicket
> > . br
> > . di Ticket
> > ..
> > .
> > .de EndTicket
> > . di
> > ..
> > .
> > .while 1 \{\
> > . StartTicket
> > .\" input for ticket text goes here
> > . EndTicket
> > . if (\n[dn] > \n[ticket-printer-paper-length]) \
> > . ab ticket too long for remaining paper; aborting
> > .\}
> >
> > Please clarify if I've overlooked a requirement.
> >
> > Regards,
> > Branden
>
> I'm probably missing something here, but ticket printers are normally
> continuous rolls with a cutter, so isn't this a problem of controlling the
> cutter rather than specifying a media size. There is usually a printer
> option
> to cut after each print job, so if you make each receipt a separate print
> job,
> it should do the cutting for you. Just give groff a sufficiently long page
> length for the longest ticket you expect.
>
> I have a Brother thermal printer which I use for labels, but it will take
> a
> continuous role instead, and I believe it has a proprietary EscP command
> for
> controlling the cutting, so there may be a solution using something
> similar.
>
> Cheers
>
> Deri
>
>
>
>
>
>
