Hi, this is presumably related to
% http://tracker.luatex.org/view.php?id=733 % http://tex.stackexchange.com/questions/65151/scantokens-in-luatex % http://tug.org/pipermail/lualatex-dev/2011-November/001376.html which address the behavior of \scantokens While investigating the issue I ended up with this, which might very well have been discussed here or is already on the tracker. If I assign catcode 12 to the CTRL-M character, and then \write ^^M to an external file: with pdftex/xetex we get ^^M (three characters) in the file with LuaTeX we get a single CTRL-M (ascii code 13) in the file as a result, the \input then behaves differently see MWE below %----START % author: jfbu % Mardi 24 mars 2015 a 19:25:11 \catcode 13 12 % \newwrite\out % \immediate\openout\out=\jobname.out % \immediate\write\out {a^^Mbcdef}% \immediate\closeout\out % \catcode 13 5 % % luatex writes to the file CTRL-M % pdftex/xetex write the three characters ^^M % as a result the input now behaves differently % luatex will see two lines, hence prints a<space>bcdef<space>+++ % pdftex/xetex see only one line with catcode 5 token and thus ignore bcdef % and print a<space>+++ \input \jobname.out +++ \bye %----STOP This is XeTeX, Version 3.14159265-2.6-0.99991 (TeX Live 2014) (preloaded format=xetex 2014.7.10) 24 MAR 2015 19:25 This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014) (preloaded format=pdfetex 2015.1.21) 24 MAR 2015 19:35 This is LuaTeX, Version beta-0.79.1 (TeX Live 2014) (rev 4971) (format=luatex 2014.7.10) 24 MAR 2015 19:36 Regards Jean-Francois
