Re: Can Bash do simple math?

[alex xmb sw ratchev]

~ $ declare -a tm
~ $ alias tm='timemark+=( $EPOCHREALTIME )'
~ $ tm
[Process completed (signal 11) - press Enter]

On Tue, Aug 6, 2024, 18:38 alex xmb sw ratchev <fxmbsw7@gmail.com> wrote:

> ~ $ alias tm='timemark+=( $EPOCHREALTIME )'
> ~ $ tm
>
> [Process completed (signal 11) - press Enter]
>
> i think this is new
> aliases like this worked all the time
>
> On Tue, Aug 6, 2024, 18:35 alex xmb sw ratchev <fxmbsw7@gmail.com> wrote:
>
>> ~ $ alias tm='timemark+=( $EPOCHREALTIME )'
>> tm ; sleep .313373 ; tm IFS=- ;
>>
>> [Process completed (signal 11) - press Enter]
>>
>> ( two lines , one alias , one rest )
>>
>> On Tue, Aug 6, 2024, 18:32 alex xmb sw ratchev <fxmbsw7@gmail.com> wrote:
>>
>>> also btw for preciese timings
>>> u need float math
>>> like with awk
>>>
>>> two methods
>>>
>>> use date +%s.%N
>>>
>>> or inline script
>>> do
>>> timemarker+=( $EPOCHREALTIME )
>>> on beginning
>>> and end
>>> and math together , like
>>>
>>> awk '{
>>>
>>> .. i was writing
>>> any idea why following exits android termux ? andro kill policy ?
>>>
>>> ~ $ alias tm='timemark+=( $EPOCHREALTIME )'    ~ $ tm ; sleep .313373 ;
>>> tm ; IFS=- ; gawk ' { print ( $0 ) } ' <<<"${timemark[*]: -2:2}"
>>> Vim: Caught deadly signal 'SIGTERM'
>>>
>>> [Process completed (signal 11) - press Enter]
>>>
>>> On Tue, Aug 6, 2024, 18:24 alex xmb sw ratchev <fxmbsw7@gmail.com>
>>> wrote:
>>>
>>>>
>>>>
>>>> On Tue, Aug 6, 2024, 17:53 Greg Wooledge <greg@wooledge.org> wrote:
>>>>
>>>>> On Tue, Aug 06, 2024 at 17:08:23 +0200, alex xmb sw ratchev wrote:
>>>>> > i really dont see why 60
>>>>>
>>>>> Because there are 60 seconds in each minute, and 60 minutes in each
>>>>> hour.
>>>>>
>>>>> Let's say you measure how long a program takes to run, and it ends up
>>>>> being 179 seconds.  You'd like to convert this number (179) to an
>>>>> interval expressed as "x minutes and y seconds".
>>>>>
>>>>> There are a few ways you can do this.  They all give you the same
>>>>> answer.
>>>>>
>>>>> The way that I find simplest to understand is always to divide by the
>>>>> next conversion factor.  So:
>>>>>
>>>>>  1) We divide 179 by 60, to get the number of minutes.
>>>>>
>>>>
>>>> u misread big
>>>> the users original code
>>>> makes , seconds minus math
>>>> the currency of it is still 1second
>>>>
>>>> now look what u write
>>>> ' to get minutes '
>>>>
>>>> i say users code has
>>>> seconds = diffinseconds % 60
>>>> not
>>>> minutes = diffinseconds % 60
>>>>
>>>> i use / 60 anyway
>>>> i must benchmark somewhen
>>>>
>>>>     We're using integer division, so any fractions are discarded.
>>>>>     179 / 60 = 2
>>>>>     So the final answer includes "2 minutes" as the first component.
>>>>>
>>>>>  2) Now that we know how many whole minutes there are, we remove those
>>>>>     from the original number.
>>>>>     2 * 60 = 120
>>>>>     We decrease the original number by 120.
>>>>>     179 - 120 = 59
>>>>>
>>>>>  3) The amount that's left over (59) is the number of seconds.
>>>>>     So our final answer is "2 minutes and 59 seconds".
>>>>>
>>>>> The conversion that the OP used is very similar to this, except they
>>>>> went for hours, minutes and seconds.
>>>>>
>>>>> Let's say you run a different program and it takes 7701 seconds, and
>>>>> you'd like to convert this to "x hours, y minutes and z seconds".  We
>>>>> can apply a similar recipe:
>>>>>
>>>>>  1) Divide 7701 by 3600 to get the number of whole hours.
>>>>>     7701 / 3600 = 2
>>>>>     "2 hours"
>>>>>
>>>>>  2) Subtract the whole hours from the original number.
>>>>>     7701 - (2 * 3600) = 501
>>>>>
>>>>>  3) Divide by 60 to get the number of minutes.
>>>>>     501 / 60 = 8
>>>>>     "8 minutes"
>>>>>
>>>>>  4) Subtract the whole minutes from the original number
>>>>>     501 - (8 * 60) = 21
>>>>>
>>>>>  5) The remaining number is the number of seconds.
>>>>>     "21 seconds"
>>>>>
>>>>> So in this case, our final answer is "2 hours, 8 minutes and 21
>>>>> seconds".
>>>>>
>>>>> The OP chose to use slightly different recipes, which involve modulus
>>>>> and which don't decrease the total as we go.  That's fine.  As I said,
>>>>> there are different ways to do it, which all give the same answer.
>>>>>
>>>>>