bind update error?

[Kevin J. Cummings]

D. Hugh Redelmeier wrote:
> | From: Mitch <mitch48 at sbcglobal.net>
> 
> | If you are running a name server check some things.
> | You have a new /etc/sysconfig/named file
> | and the line 224 in  /usr/sbin/bind-chroot-admin
> | is making a test in this context:
> | 
> |     . /etc/sysconfig/named
> |     if [ "$ENABLE_ZONE_WRITE" =  [yY1]* ]; then
> |         return 0;
> |     fi;
> 
> That test is bogus in several ways.  Unless the man page expr(1) is
> bogus (never trust GNU-generated man pages).
> 
> The shell command "[" is supposed to be another name for "expr".

No, "[" is another name for "test"  See the CONDITIONAL EXPRESSIONS
section of "man bash"

> In expr, the binary operator "=" does not take regular expressions.
> So the "[yY1]*" makes no sense.  The test does not do what the author
> appears to think it will do.
> 
> But it is worse than that.  The shell does globbing on this operand
> since it isn't quoted.  So [yY1]* would get expanded to the list of
> filenames in the current directory whose names start with y, Y, or 1.
> If none match it would remain unchanged.  The result would be passed
> to the expr.  If it was a list, that would be a mess.  If it were a
> single item, it would just be wrong.
> 
> My guess is that the current directory has several matching files and
> the resulting list provokes a syntax error message from expr.
> 
> Perhaps the correct test is
>       if [ "$ENABLE_ZONE_WRITE" : '[yY1]*' ]; then
>                                 ^ ^      ^
> 
> Whoever wrote this script cannot have tested the "then" path of this
> if.
> 
> I've added a Bugzilla entry:
> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=241608
> 


-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)