[erlang-questions] How to find the full OTP release number (including patch level)?

[Per Hedeland]

Bill Clementson <billclem@REDACTED> wrote:
>
>Mats Cronqvist <mats.cronqvist <at> ericsson.com> writes:
>
>> 
>> Bill Clementson wrote:
>> > So is there any "canonical" way that erlangers condition code based on 
>> > functionality that is in a specific patch level of a release? 
>> 
>> 1> erlang:system_info(version).
>> "5.5.4"
>> 
>>    this is the erts version. version X.Y.Z is roughly the same as "R"Y+6"B-"Z 
>> (e.g. 5.5.4 is R11B-4).
>
>Thanks.

Take note of the "roughly" though - e.g. this is R10B-7:

1> erlang:system_info(version).
"5.4.9"

- and this is R10B-9:

1> erlang:system_info(version).
"5.4.12"

AFAIK there isn't even a guarantee that the Y+6 will hold (it certainly
doesn't if you go way back, where X was 4). I.e. Björn's answer is (of
course) the only correct one. Then again, for erts functionality (like
the existence of a BIF), the erts version is what you *should* check...

--Per Hedeland