MiKTeX failed to test file existence for /dev/null, on macOS and Linux

[Liam0205]

• I have read the MiKTeX Contributing Guidelines

As mentioned by @fylimas in #77 (comment), MiKTeX failed to test OS on macOS and Linux. The origin of the problem rooted in the failure of a file existence test: /dev/null.

Both CTeX (CTeX-org/ctex-kit#340 and CTeX-org/ctex-kit#313) and ifplatform consider Windows if /dev/null doesn't exist. However, MiKTeX always gives False by the following test, on macOS and Linux, which cause problems:

\ExplSyntaxOn
\file_if_exist:nTF { /dev/null } { True } { False }
\ExplSyntaxOff

Please consider to check and fix it. Thanks!

---

MWE:

% macOS High Sierra 10.13
% MiKTeX 2.9.6637
% CTeX 2.4.14
% xelatex --shell-escape mwe.tex
\documentclass{article}
\usepackage{ifplatform}
\usepackage[fontset=none]{ctex}

\begin{document}

ifplatform test:\\
\ifshellescape shell escape on\else shell escape off\fi\\
\IfFileExists{/dev/null}{dev null exists}{dev null not exists}\\
\ifwindows windows true \else windows false \fi

\ExplSyntaxOn
\LaTeX3 ~ test: \\
\file_if_exist:nTF { /dev/null } { dev ~ null ~ exists } { dev ~ null ~ not ~ exists } \\
\file_if_exist:nTF { /Library/Fonts/Songti.ttc } { Library ~ Fonts ~ Songti ~ exists } { Library ~ Fonts ~ Songti  ~ not ~ exists } \\
\ctex_detected_platform:
g_ctex_fontset_tl: ~ \g__ctex_fontset_tl \\
\ExplSyntaxOff

\end{document}

Result:

ifplatform test:
shell escape on
dev null not exists
windows true
LATEX3 test:
dev null not exists
Library Fonts Songti exists
g_ctex_fontset_tl: windows

[Liam0205]

c.c. @leo-liu @qinglee @WenboSheng

[edocevoli]

Thank you for the report. This has been fixed now.