Pdflatex began stopping on \showthe?

OK, this I cannot really understand..

Basically, I use `scite` that calls a `lua` script, and through that, `pdflatex`. (If `scite` is ran from a terminal, then the `pdflatex` output called through it is dumped to the same terminal, and then one can also interact with `pdflatex`, in case of errors)

Today, I added to one of my files:

``````\showthe\paperheight
\showthe\pdfpageheight
\showthe\paperwidth
\showthe\pdfpagewidth
``````

... and I'd run `pdflatex` as usual - and I'd notice this in the log:

``````? > 0.0pt.
l.6 \showthe\paperheight

? > 845.04684pt.
l.7 \showthe\pdfpageheight

? > 0.0pt.
l.8 \showthe\paperwidth

? > 597.50787pt.
l.9 \showthe\pdfpagewidth
``````

... and `pdflatex` kept on going, and all was fine.

Then, I keep working - and suddenly, `pdflatex` does not run over the `\showthe` commands anymore; instead, it starts waiting for a user input! Here I'd answer with 'scroll', i.e.

``````? > 845.04684pt.
l.7 \showthe\pdfpageheight

? S
OK, entering \scrollmode...
> 0.0pt.
l.8 \showthe\paperwidth

> 597.50787pt.
l.9 \showthe\pdfpagewidth
``````

... and then it would run through the end!

Now, I am forced to call `pdflatex` like:

``````pdflatex -interaction=scrollmode file.tex ...
``````

... so as to cause `pdflatex` to 'run through' these commands - but now I'm afraid it will not stop on some more serious error (where I'd otherwise prefer it to stop).

Does anyone have an idea about what happened here - and how do I get my old `pdflatex` behavior back?

``````\$ pdflatex --version
pdfTeX 3.1415926-1.40.10-2.2 (TeX Live 2009)
kpathsea version 5.0.0
\$ uname -r
2.6.32-26-generic
``````

Cheers!

-
Reading this question title, for a horrified moment I thought it meant TeX used C-style trigraphs. – Peter LeFanu Lumsdaine Nov 9 '11 at 16:32

``````\the\paperheight
``````\typeout{=== \the\paperheight ===}%
Thanks @Herbert! Wasn't sure really what was the default behavior... Now, I'd just need to discover how come `pdflatex` behaved as it did, without any particular command line switches ?! Thanks in any case... – sdaau Dec 19 '10 at 15:55
`\scrollmode` in the code triggers the same behavior as the flag `--interaction=scrollmode`. – Philipp Dec 19 '10 at 19:04