In this case the values are hardcoded, so Colin was just warning about the
off-by-one counting difference between these two (functionally identical)
commands:
head -n -31
tail -n +32


On 16 August 2014 12:00, Chris Moore <[email protected]>
wrote:

> You mean $((X+1)), not $(X+1), right?
>
> $ X=42
> $ echo $(X+1)
> No command 'X+1' found, did you mean:
>  Command 'X11' from package 'x11-common' (main)
> X+1: command not found
>
> $ echo $((X+1))
> 43
>
>
>
> On Fri, Aug 15, 2014 at 5:31 PM, Bob <[email protected]> wrote:
>
>>
>> On 8/15/2014 10:52 AM, Bob wrote:
>>
>>>
>>> On 8/15/2014 9:47 AM, Colin Percival wrote:
>>>
>>>> [CCing Alex since it's his code we're talking about here...]
>>>>
>>>> On 08/15/14 09:19, Bob wrote:
>>>>
>>>>> On 8/14/2014 4:55 PM, Colin Percival wrote:
>>>>>
>>>>>> On 08/14/14 14:55, Bob wrote:
>>>>>>
>>>>>>> I am running ACTS to do my backups and cleanup my archive.
>>>>>>> Everything was fine
>>>>>>> for a month or so, now I get "
>>>>>>>
>>>>>>> head: illegal line count -- -31" at the end of the tarsnap backup.
>>>>>>> As far as I
>>>>>>> can tell, everything is still being backed up, but this message must
>>>>>>> mean
>>>>>>> something. Can anyone help?
>>>>>>>
>>>>>> That would be a problem with the script you're using -- looks like
>>>>>> it's in the
>>>>>> part of the script which deletes old daily backups.  The "-n negative
>>>>>> number"
>>>>>> option to the head utility is nonportable and presumably doesn't
>>>>>> exist on your
>>>>>> operating system.
>>>>>>
>>>>>>  That makes sense. I am using freeBSD 9.2. The only thing is that
>>>>> daily backup
>>>>> removal was going fine for a while. I am not an expert at this. Is
>>>>> there a fix
>>>>> or a different way to attack backup management?
>>>>>
>>>> Probably you never had an error earlier because you had less than 31
>>>> daily
>>>> backups and so none of them needed to be deleted.
>>>>
>>>> I think the easiest solution here is for 'head -n -X' to be replaced by
>>>> 'sort -rn | tail +$(X+1)' -- Alex, do you want to make this change?
>>>>
>>>>  Thanks so much for the fix!
>>>
>>
>> I spoke too soon. Now, when I run acts.sh (after changing the lines for
>> head), I get "
>>
>> /var/run/acts exists referencing PID <none>, aborting!"
>>
>> Seems odd.
>>
>>
>>
>

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