2019-08-01 02:08:59 -0600, Assaf Gordon: [...] > Three notes: > 1. > I would recommend using "-%7.0f minutes" format in "seq" > instead of "%g", as the latter will result in a scientific notation > for large values: > > $ seq -f '-%7g minutes' 2563200 | tail -n1 > -2.5632e+06 minutes > > $ seq -f '-%7.0f minutes' 2563200 | tail -n1 > -2563200 minutes
Good point, though $ seq -f '-%7.0f minutes' 1 - 1 minutes You'd want: seq -f '-%.0f minutes' 2563200 Or seq -f '%.0f minutes' -- -1 -1 -2563200 [...] > For reference, on my old desktop it takes: > > $ time seq -f "2019-08-01 01:53:22Z +%7.0f minutes" 2563200 \ > | date -u -f - +%Y%m%d_%I%M%p \ > | datamash --full md5 1 | wc -l -c > 2563200 125596800 > > real 0m14.185s > user 0m17.739s > sys 0m0.527s > > And results in ~125MB of data - reasonable for an ad-hoc reverse > lookup table for MD5 values. [...] Thanks. I definitely need to have a better look at datamash. -- Stephane
