Bash script taking account a leap year

TB0ne · 05-07-2016, 06:13 PM

Quote:

Originally Posted by theki

Hello I am new at bash, the question is that I am creating a bash script which it shows the number of days in a month using arguments like "./numberMonth.sh 3 2016" and taking account a leap year.
I am having difficult to make it, can anyone help me a little?
I wrote this:

And it shows the number of days(31) but I want the name of month followed by the number of days like "March has 31 days"
I tried with echo command and doesn't work.

Read the "Question Guidelines" link in my posting signature. We are happy to help you with a script, but you've posted a single command...show us what you have written/tried on your own, and we will help.

Habitual · 05-07-2016, 07:17 PM

If you want to " taking account a leap year" then March is the wrong month.
http://xyproblem.info/

grail · 05-08-2016, 04:50 AM

I am not sure what the leap year part has to do with the question? You are going to supply the year and the numeral version of the month which cal will then return the necessary information (including
return 29 days for February if needed).

A simple awk seems to do the trick.

HMW · 05-08-2016, 07:39 AM

Quote:

Originally Posted by grail

A simple awk seems to do the trick.

Yep. Managed to do this with cal | tail | awk

You can do this using echo | tail

Another way is to use Python and monthrange, or php and cal_days_in_month

But the first way is probably fastest.

/HMW

TB0ne · 05-08-2016, 08:50 AM

...and this, right here, is why I always quote the original questions. The OP came and deleted what they posted, instead of posting what they ACTUALLY DID to solve their issue.

grail · 05-08-2016, 03:54 PM

Yes ... poor form on behalf of the OP

So for others, here was my solution:

Code:

cal 3 2016 | awk 'NR == 1 { b = $1}NF{a = $NF}END{print b,"has",a,"days"}'

HMW · 05-09-2016, 02:18 AM

This is what I boiled it down to:

Code:

$ echo $(cal 5 2016) | tail -c 3
31

Best regards,
HMW

Edit: Just now I reread OP's original question. He/she also wants the name of the month. It's done fairly easy using my, or grail's approach. DS.

Habitual · 05-09-2016, 06:25 AM

Quote:

Originally Posted by grail

I am not sure what the leap year part has to do with the question?

Well, as much as I love "date math" in bash, I'd still have to defer to other more experienced
opinions, such as grail's.

keefaz · 05-09-2016, 09:30 AM

Code:

date -d "5/1/2016 next month yesterday" "+%B has %d days"

Habitual · 05-09-2016, 09:55 AM

Quote:

Originally Posted by keefaz

Code:

date -d "5/1/2016 next month yesterday" "+%B has %d days"

Now you're just showing off!

HMW · 05-10-2016, 02:21 AM

Quote:

Originally Posted by keefaz

Code:

date -d "5/1/2016 next month yesterday" "+%B has %d days"

Bravo!

AnanthaP · 05-10-2016, 06:17 AM

yesterday's solution cal 3 2016 | grep -v [a-z] | wc -w also seems to be deleted.