PostScript - how to debug PostScript

Author

how to debug PostScript

lkrubner@geocities.com

2005-11-10, 7:01 pm

I was about to ask "How do you debug PostScript" but it sounded to me
like an FAQ type of question, so I ran a search on groups.google.com
first. I was surprised that nearly all the posts were from the
1990s.One from 1998 was about a product called PSAlster that everyone
seemed to like.

What are people doing this decade? Besides print lots of junk?

janus.astrolabe@verizon.net

2005-11-10, 7:01 pm

I can't speak for others, but I find PostScript to be no more difficult
to debug than other languages and I write a lot of C, C++ and Intel
Assembler. Basically, what you need to know is what didn't work and
the state of the program when it failed. My own PS coding is either
from scratch or program generated pictures. I don't do much text work
in PS except for labels on pictures. The book I am working on has over
250 eps figures and it has become somewhat easier to write and debug as
I gained experience.

I try to keep it simple so I just use Ghostview. I create the ps or
eps file and save it. Then, I display it with Ghostview. If the
picture has an error but the file runs without error, I have to figure
out my logic error which I usually do by taking checkpoints by
inserting an invalid command (I use "blow") in the code to see the
stack at various points in the program. If the PS blows with an error
I have found that just being able to see the stack and the problem
statement is usually enough, given that some errors are harder to track
down than others.

I tend to build pictures in steps from the easy, basic shapes and then
get more complicated. Sometimes, particularly for PS programs
generated from a C or C++ program, it helps to write computed values
into the PS output as comments so I can see what the PS is working
with.

In summary, Ghostview is a fabulous debugging tool, but the more
general programming experience you have, the easier it is work with PS.

Best regards,

Jim

lkrubner@geocities.com wrote:
> I was about to ask "How do you debug PostScript" but it sounded to me
> like an FAQ type of question, so I ran a search on groups.google.com
> first. I was surprised that nearly all the posts were from the
> 1990s.One from 1998 was about a product called PSAlster that everyone
> seemed to like.
>
> What are people doing this decade? Besides print lots of junk?

Jim Land

2005-11-10, 7:01 pm

> lkrubner@geocities.com wrote:
>

PSAlter is still around, and is still the premier PS debugging tool for
serious PS programming. Check out their free trial on the order page.

http://www.quite.com/psalter/

hoffmann@fho-emden.de

2005-11-10, 7:01 pm

PSAlter is fine, but restricted to PS Level 2.

IMO it should have at least a few features of PS 3, mainly
Gouraud shading for quadrilaterals.
This would be very helpful for programming illustrations
with color gradients.

Best regards --Gernot Hoffmann

François Robert

2005-11-10, 7:01 pm

lkrubner@geocities.com wrote in news:1131138058.145814.103400
@g44g2000cwa.googlegroups.com:

> I was about to ask "How do you debug PostScript" but it
> sounded to me like an FAQ type of question, so I ran
> a search on groups.google.com first. I was surprised
> that nearly all the posts were from the 1990s. One from
> 1998 was about a product called PSAlster that everyone
> seemed to like.
>
> What are people doing this decade? Besides print lots of junk?
>

http://wxghostscript.sourceforge.net/

which can be found under the third link returned by

http://groups.google.co.uk/groups?
q=debugging++group:comp.lang.postscript&start=0&scoring=d

(query Usenet "comp.lang.postscript" for "debugging", ordered by date)
________________________________________
_______________
François Robert
(to mail me, reverse character order in reply address)

Sponsored Links