Re: [libvirt] [patch 2/5] Instantiate comments in ip(6)tables rules

On 09/24/2010 02:22 PM, Stefan Berger wrote: > I just tried the TCK test without and with double-escaping in libvirtd > and double-escaping does seem to be necessary otherwise `ls` and $(ls) > do get executed and their results end up in the comment. The spaces > are preserved, though, so I can revert the change to IFS. Hmm. > "res=`eval \"$cmd\"" CMD_SEPARATOR > + virBufferVSprintf(buf, > + " -m comment --comment \\\"%s\\\"", > + cmt); Thinking about it more:

My suggestion is to assign cmd using '' rather than "" (fewer things to quote), as well as moving the eval outside of the `` (so it becomes obvious which \ are interpreted by eval rather than by ``: cmd='iptables -m comment --comment '\''user $comment'\'' eval res=\`"$cmd"\` res=`iptables -m comment --comment 'user $comment'` And the nice part of that is the implementation: virBufferVSprintf(buf, " -m comment --comment '%s'", escapeSingleQuotes(user_comment)); virBufferVSprintf(cmd, "cmd='%s'\nres=\\`\"$cmd\"\\`", escapeSingleQuotes(buf));

On further thought, gnulib might be doing: #define strchr rpl_strchr on platforms where strchr is broken, so using #undef strchr is too risky. So I'd recommend sticking with (strchr)(a, b), which still works

if gnulib has to replace a broken strchr.