Patch ShellEscape
Packages such as pdftricks.sty, epstopdf.sty (or pdftex.def)
call external programs. They do not work at all, if the
\write18 feature is not enabled. Therefore a robust method
would be useful in order to inform the user. For security
reasons the \write18 featuer must not be set by TeX macro
code.
Thus the patch introduces a new readonly primitive
\pdfshellescape that expands to "0" if the \write 18 feature
is disabled and "1" in the other case.
Use, for instance:
\ifnum\pdfshellescape=0
\message{The \string\write18 feature is disabled.}
\else
\message{The \string\write18 feature is enabled.}
\fi
Patch files:
pdftex.ch.diff for TeX/texk/web2c/pdftexdir/pdftex.ch
pdfetex.ch2.diff for TeX/texk/web2c/pdfetexdir/pdfetex.ch2
Yours sincerely
Heiko