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Cron job every three days
Is it possible to run a cronjob every three days? Or maybe 10 times/month.
11 Answers
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How do I execute a command and get the output of the command within C++ using POSIX?
...ited Dec 5 '18 at 2:16
gregpaton08
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answered Jan 26 '09 at 6:12
waqaswaqas
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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...le(a = c(1, 2), b = c(11, 12))
newDT <- DT
.Internal(inspect(DT))
# @0000000003B7E2A0 19 VECSXP g0c7 [OBJ,NAM(2),ATT] (len=2, tl=100)
# @00000000040C2288 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 1,2
# @00000000040C2250 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 11,12
# ATTRIB: # ..snip..
.Inte...
Finding quaternion representing the rotation from one vector to another
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answered Jul 23 '09 at 14:04
Polaris878Polaris878
31.6k3535 gold badges105105 silver badges139139 bronze badges
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How to sleep for five seconds in a batch file/cmd [duplicate]
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30 Answers
30
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What is this operator in MySQL?
...e the regular = operator, two values are compared and the result is either 0 (not equal) or 1 (equal); in other words: 'a' <=> 'b' yields 0 and 'a' <=> 'a' yields 1.
Unlike the regular = operator, values of NULL don't have a special meaning and so it never yields NULL as a possible outco...
Checking images for similarity with OpenCV
...ue (maybe a percentage) that indicates how similar these images are? E.g. 100% would be returned if the same image was passed twice, 0% would be returned if the images were totally different.
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How do I create a dictionary with keys from a list and values defaulting to (say) zero? [duplicate]
I have a = [1,2,3,4] and I want d = {1:0, 2:0, 3:0, 4:0}
5 Answers
5
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Code Golf: Collatz Conjecture
Inspired by http://xkcd.com/710/ here is a code golf for it.
70 Answers
70
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How can I implode an array while skipping empty array items?
...ode('-', array_filter($array));
Obviously this will not work if you have 0 (or any other value that evaluates to false) in your array and you want to keep it. But then you can provide your own callback function.
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