Hello, I slightly modified the example - my code now is: ---- \ctxlua{os.execute([[echo lua -e "print 'WWW'"]])} \starttext A \stoptext ---- So now I'm able to diagnose what exactly is passed to the command line. I'm getting: " ... languages > language en is active lua -e "print "WWW"" {c:/ConTeXt/tex/texmf-context/fonts/map/pdftex/context/mkiv-base.map} ... " So it can be seen that [surprisingly] character ' was substituted for " - and IMHO this causes the problem. Could anyone explain why this substitution is performed and how to avoid it? Best regards, Lukas -- Ing. Lukáš Procházka [mailto:LPr@pontex.cz] Pontex s. r. o. [mailto:pontex@pontex.cz] [http://www.pontex.cz] Bezová 1658 147 14 Praha 4 Tel: +420 244 062 238 Fax: +420 244 461 038