On Thu, 23 Sep 2004, Michal Marek wrote: > grep -E '^([^ax]|a[^b]|x[^y]|ab[^c]|xy[^z]|a$|x$|ab$|xy$)*$' Spatne. Zkuste retezec "ababca". Udela z nej: (aba)(b)(c)(a) a projde to. --Pavel Kankovsky aka Peak [ Boycott Microsoft--http://www.vcnet.com/bms ] "Resistance is futile. Open your source code and prepare for assimilation."