[arch-projects] [initscripts] [PATCH 20/20] Catch all errors within status blocks

[Kurt J. Bosch]

Tom Gundersen, 2011-07-10 22:11:
> On Sun, Jul 10, 2011 at 6:57 PM, Kurt J. Bosch
> <kjb-temp-2009 at alpenjodel.de>  wrote:
>> Rationale:
>> Instead of ignoring any errors of all commands but the last within a status
>> block it is much better to use trap to catch them and report 'FAIL'. One
>> might for example miss the utmp group which is needed to propperly install
>> /var/run/utmp.
>> This also makes the code a bit more simple and readable.
>>
>> Note:
>> We enable this explicitely (by calling stat_err_trap) because most daemon
>> scriptlets don't work well with this by now. Moreover we don't use 'set -E'
>> to avoid breaking/complicating [custom/hook] functions.
>
> I think this is too complicated for too little gain, especially if it
> will not work everywhere and has to be enabled explicitly. We should
> avoid being too clever I think. If we want to check for more exit
> statuses we should add more " || stat_fail".
>
> -t

OK here we go:

  1st alternative
-----------------

functions:

stat_done() {
   printf ...
   STAT_ERR=0
}

stat_fail() {
   printf ...
   STAT_ERR=1
}

stat_done() {
   (( STAT_ERR )) && return 0
   printf ...
}

rc.sysinit:

stat_busy "Removing Leftover Files"
   rm -rf /etc/{nologin,shutdownpid} /forcefsck /tmp/* /tmp/.[^.]* 
/tmp/..?* /var/run/daemons || stat_fail
   [[ ! -L /var/lock ]] && rm -rf /var/lock/* || stat_fail
   if [[ ! -L /var/run && -d /var/run ]]; then
     find /var/run/ \! -type d -delete || stat_fail
     ln -s /run/daemons /var/run/daemons || stat_fail
   fi
   install -Tm 0664 -o root -g utmp <(:) /var/run/utmp || stat_fail
   # Keep {x,k,g}dm happy with xorg
   mkdir -m 1777 /tmp/.{X11,ICE}-unix || stat_fail
stat_done

  2nd alternative
-----------------

rc.sysinit:

stat_busy "Removing Leftover Files"; e=0
   rm -rf /etc/{nologin,shutdownpid} /forcefsck /tmp/* /tmp/.[^.]* 
/tmp/..?* /var/run/daemons || e=1
   [[ ! -L /var/lock ]] && rm -rf /var/lock/* || e=1
   if [[ ! -L /var/run && -d /var/run ]]; then
     find /var/run/ \! -type d -delete || e=1
     ln -s /run/daemons /var/run/daemons || e=1
   fi
   install -Tm 0664 -o root -g utmp <(:) /var/run/utmp || e=1
   # Keep {x,k,g}dm happy with xorg
   mkdir -m 1777 /tmp/.{X11,ICE}-unix || e=1
(( e )) && stat_fail || stat_done

Both look very ugly and are even more complicated IMHO.

I admit this is not really urgent as long as no bug reports arise which 
would suggest catching more errors.

-- 
Kurt