On Wed, Oct 06, 2010 at 06:51:05AM -0600, Serge Dubrouski wrote:
> On Wed, Oct 6, 2010 at 5:51 AM, Lars Ellenberg
> <[email protected]> wrote:
> > On Wed, Oct 06, 2010 at 01:31:07PM +0900, [email protected] wrote:
> >> Hi Serge,
> >>
> >> I confirm the movement of your patch from now on.
> >> And I am going to contribute the patch of the change of loglevel of the
> >> monitor processing at the time
> >> of the start.
> >>
> >> However, there is a problem to your this patch.
> >> The -q option of the monitor is lost.
> >>
> >> - runasowner -q "$OCF_RESKEY_psql $psql_options -c 'select now();'"
> >> + runasowner "$OCF_RESKEY_psql $psql_options -c
> >> '$OCF_RESKEY_monitor_sql'"
> >
> > Make sure you properly shellescape OCF_RESKEY_monitor_sql first,
> > or you'll get unexpected results -- it may contain single qutotes itself.
>
> Thanks. Attached is the final (I hope) version of this patch.
> - runasowner -q "$OCF_RESKEY_psql $psql_options -c 'select now();'"
> + runasowner -q "$OCF_RESKEY_psql $psql_options -c
> \"$OCF_RESKEY_monitor_sql\""
Nice try ;-)
It may contain double quotes just the same.
my_runasowner() {
# actually is is su $someuser -c "$*", but
# for demo it's equivalent to:
bash -c "$*";
}
x="blub"
my_runasowner "echo blah $x"
blah blub
expected.
x="; echo blub"
my_runasowner "echo blah $x"
blah
blub
oh. let's quote it.
x="; echo blub"
my_runasowner "echo blah \"$x\""
blah ; echo blub
yes, we fixed it.
Or, did we?
x="\"; echo blub\""
my_runasowner "echo blah \"$x\""
blah
blub
Oh ;(
You have to _shell escape_ that variable. Not add quotes around it in a
string that will be passed as input to a subshell.
In sufficiently recent bash, you could do
printf -v escaped %q "$unescaped", and be done with it.
In stupid sh, you may have to do something similar to
escaped=$(echo "$unescaped" | sed -e "s/'/'\\\\''/g"):
x="'; echo \\ \$(uname -a); echo blub'"
x=$(echo "$x" | sed -e "s/'/'\\\\''/g")
my_runasowner "echo blah '$x'"
blah '; echo \ $(uname -a); echo blub'
Seems like we're good, after all.
end-of-shell-quoting-workshop
--
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com
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