2006/12/26, Peter Münster <pmlists at free.fr>:
> There is such a command in pdfTeX-1.40 but I don't remember the name
> (I think it's "\ifshellescape").
It's new in 1.30:
- \pdfshellescape is a read-only integer that is 1 if \write18 is enabled, 0
otherwise.
Best
Martin