<html> I have to write some BASH scripts.We have all heard about security problems with shell variables(i.e. when entering a name someone enters something like "Tony; rm -rf /root/*" )so that if the BASH scripts echoes it will will do something like echo Tony; rm -rf /root/*. Now we have honest users here, but I still want to do some checks. If I read in or get a shell variable from a userI could do something like echo "$VAR" | grep '[^a-zA-Z/_-]' if [ $? -eq 0 ] then echo "You have entered a bad character" exit 1 fi but that still runs into the problem like above with the echo. I also could do case "$VAR" in \;|\:) echo "you have a bad character" ;; esac but I am not sure that is best either. Is there anyway to validate shell variables?I know Javascript, etc., has something like url_encode() </html>