Take the 2-minute tour ×  I have a bash script which runs as
root:  /var/bin/svn_co -h $1 >> /var/log/svn/status.log  If the
following should somehow occur, I'm in trouble.
/var/svn/hooks.d/post-commit -h `rm / -fr`  I would like to take
rm / -fr and remove all instances of ` from it.  How does one
simply strip the grave accent? Or, even better, how does one
validate variables and options provided as input?  share|improve
this question add comment  1 Answer  This is one of the reasons
why we use quotes.  /var/bin/svn_co -h "$1" >>
/var/log/svn/status.log share|improve this answer Sometimes even
double quotes. :) –  jscott May 9 '12 at 22:56 But a string with
backticks in it will stay literal anyway unless eval'd, just
tried it. The quotes are necessary for other reasons though
(whitespace can otherwise easily add unintended arguments to
svn_co!). For really paranoid filtering, something like
var=${var//[^[:alpha:]]/} (thanks again to another posters hint
at regex brace subst!) would probably come closest, at