possible bug with start-stop-daemon and --test?

[Ed W]

On 04/04/2011 00:51, Denys Vlasenko wrote:
> On Thursday 31 March 2011 17:24, Ed W wrote:
>> Hi, the "full-fat" version of start-stop-daemon tends to be used in init
>> scripts using the --test option to see if the daemon is actually running
>> or crashed.  This isn't obviously working as expected for me with
>> busybox-1.18.3 ?
>>
>>   $ start-stop-daemon -K --test --pidfile /tmp/my.pid && echo true
>>   stopped process in pidfile '/tmp/my.pid' (pid 999999999)
>>   true
>>
>> I think the current behaviour isn't expected (man page says it should
>> return non zero)?  Would a fix be straightforward?
> 
> Yes, fixing this should be easy. But first, what is the expected behavior,
> including the message? "stopped process in pidfile FOO" doesn't
> look good... what "standard" start-stop-daemon says in this case?
> 

I think there might be a cut'n'paste typo here in that I may have
removed a "-v" from my command above.  Full repro case here:


Using start-stop-daemon from "openrc 0.6.8" (gentoo amd64)

# echo 9999999 > /tmp/my.pid && start-stop-daemon -K --test --pidfile
/tmp/my.pid -v && echo true
 * Will stop PID in pidfile `/tmp/my.pid'
 * start-stop-daemon: no matching processes found


On busybox 1.18.3

$ echo 9999999 > /tmp/my.pid && start-stop-daemon -K --test --pid
file /tmp/my.pid -v && echo true
stopped process in pidfile '/tmp/my.pid' (pid 9999999)
true

(note the "true" result returned with busybox?  $? is 1 with openrc,
it's 0 with busybox)


Expected behaviour is noted here:
	http://www.busybox.net/BusyBox.html

-K only:
        -t,--test         Match only, exit with 0 if a process is found

Obviously it's not explicit about return value if the process is NOT
found, but I think it's inferred that it shouldn't be zero?  I only have
gentoo machines to hand, but as a data point they return 1 in the event
of a process not found?

# echo 9999999 > /tmp/my.pid && start-stop-daemon -K --test --pidfile
/tmp/my.pid -v; echo "return: $?"
 * Will stop PID in pidfile `/tmp/my.pid'
 * start-stop-daemon: no matching processes found
return: 1


In the case of Gentoo the startup scripts use the idiom above quite a
bit to check for correct startup, crashed jobs and whether to cleanup
dead pids.  So with -t always returning 0 it's somewhat neutered some of
my init scripts?  (I guess other distros are moving to fancy upstart
derivatives so might not have noticed?)

Thanks for any help resolving?

Ed W