Am Tue, 22 Dec 2015 08:16:28 -0500 schrieb Greg Wooledge <wool...@eeg.ccf.org>:
> On Tue, Dec 22, 2015 at 04:04:16AM +0100, Ángel González wrote: > > Aren't you making things more complex than needed, with so much > > pipes and awk? > > > > date(1) is your friend: > > > > For instance: > > $ for y in {1900..2199} ; do echo -n "$y "; for m in {1..12}; do > > date +%A -d $y-$m-13; done | grep -c Friday ; done > > > > shows there are between 1 and 3 Fridays per year. > > This is the most obvious approach, but it does a fair amount of > forking. Also, you're relying on GNU date. And on the assumption that Friday is called „Friday“ in the used locale which is a bit surprising since Ángel's name suggests that it is called differently in his native locale. It is called „Freitag“ in mine so I got no Friday 13th at all.