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From: Chris on 1 Apr 2010 06:53
HI
Im trying to get this condition to work.

If snmpwalk command works correctly (i.e. returns status code of 0 -
community string ok etc) and does not return a string (i.e. matching
alarm I want from grep) then return either success code or a certain
string I can use in my condition/action.

I have tried

test1=`snmpwalk -v2c -c public localhost 2>&1 | grep "myalarm"`
echo $test1

But the status code returns fail (i.e. return 1) if snmpwalk doesnt
work (which I want), but return a success if the string is either
found or not found. I want to have

return 1 if either command does not work or string is found.
return 0 if command works and matching string not found.

Is there a way to do this in one command?
Cheers









From: Bill Marcum on 1 Apr 2010 07:49
On 2010-04-01, Chris <cconnell_1(a)lycos.com> wrote:
> HI
> Im trying to get this condition to work.
>
> If snmpwalk command works correctly (i.e. returns status code of 0 -
> community string ok etc) and does not return a string (i.e. matching
> alarm I want from grep) then return either success code or a certain
> string I can use in my condition/action.
>
> I have tried
>
> test1=`snmpwalk -v2c -c public localhost 2>&1 | grep "myalarm"`
> echo $test1
>
> But the status code returns fail (i.e. return 1) if snmpwalk doesnt
> work (which I want), but return a success if the string is either
> found or not found. I want to have
>
> return 1 if either command does not work or string is found.
> return 0 if command works and matching string not found.
>
> Is there a way to do this in one command?
> Cheers
>
The command "echo $test1" returns 0. If you want to use $? from the
pipe, you have to get it before the echo. If you use bash, you can
check ${PIPESTATUS[*]} to see whether snmpwalk or grep failed.


--
Alexander Hamilton started the U.S. Treasury with nothing - and that was
the closest our country has ever been to being even.
-- The Best of Will Rogers
From: Chris on 1 Apr 2010 09:15
On Apr 1, 1:49 pm, Bill Marcum <marcumb...(a)bellsouth.net> wrote:
> On 2010-04-01, Chris <cconnel...(a)lycos.com> wrote:
>
> > HI
> > Im trying to get this condition to work.
>
> > If snmpwalk command works correctly (i.e. returns status code of 0 -
> > community string ok etc) and does not return a string (i.e. matching
> > alarm I want from grep) then return either success code or a certain
> > string I can use in my condition/action.
>
> > I have tried
>
> > test1=`snmpwalk -v2c -c public localhost 2>&1 | grep "myalarm"`
> > echo $test1
>
> > But the status code returns fail (i.e. return 1) if snmpwalk doesnt
> > work (which I want), but return a success if the string is either
> > found or not found. I want to have
>
> > return 1 if either command does not work or string is found.
> > return 0 if command works and matching string not found.
>
> > Is there a way to do this in one command?
> > Cheers
>
> The command "echo $test1" returns 0. If you want to use $? from the
> pipe, you have to get it before the echo. If you use bash, you can
> check ${PIPESTATUS[*]} to see whether snmpwalk or grep failed.
>
> --
> Alexander Hamilton started the U.S. Treasury with nothing - and that was
> the closest our country has ever been to being even.
>                 -- The Best of Will Rogers

Thanks, I checked pipe status, is there a way for grep to return
status code 0 if the the string is "not" found? i.e. grep in reverse.
From: Jean-Rene David on 1 Apr 2010 10:08
* Chris [2010.04.01 13:15]:
>> > I have tried
>>
>> > test1=`snmpwalk -v2c -c public localhost 2>&1 | grep "myalarm"`
>> > echo $test1
>>
>> > But the status code returns fail (i.e. return 1) if snmpwalk doesnt
>> > work (which I want), but return a success if the string is either
>> > found or not found. I want to have
>>
>> > return 1 if either command does not work or string is found.
>> > return 0 if command works and matching string not found.
>>
>> > Is there a way to do this in one command?

Not sure this counts as one command:

x="$(snmpwalk -v2c yadayada...)" && \
if printf "$x" | grep -q myalarm ; then /bin/false ; fi

This will return the status code of "snmpwalk" if "snmpwalk"
fails, or 1 (the return value of /bin/false) if "myalarm" is
found in the output of "snmpwalk".

Maybe others can improve it.

Hope this can get you started.

--
JR
From: Thomas 'PointedEars' Lahn on 1 Apr 2010 10:51
Chris wrote:

> Bill Marcum wrote:
>> Chris wrote:
>> > test1=`snmpwalk -v2c -c public localhost 2>&1 | grep "myalarm"`
>> > echo $test1
>> >
>> > But the status code returns fail (i.e. return 1) if snmpwalk doesnt
>> > work (which I want), but return a success if the string is either
>> > found or not found. I want to have
>> >
>> > return 1 if either command does not work or string is found.
>> > return 0 if command works and matching string not found.
>> >
>> > Is there a way to do this in one command?
>> > [...]
>>
>> The command "echo $test1" returns 0. If you want to use $? from the
>> pipe, you have to get it before the echo. If you use bash, you can
>> check ${PIPESTATUS[*]} to see whether snmpwalk or grep failed.
>> [...]
>
> Thanks, I checked pipe status, is there a way for grep to return
> status code 0 if the the string is "not" found? i.e. grep in reverse.

Yes. And trim your quotes, please.

<http://www.catb.org/~esr/faqs/smart-questions.html>


PointedEars
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