Bash scripting question (CAL & DATE)

Coldmiser · 05-10-2010, 12:42 PM

Hi,

I am trying to create a calendar (on the fly) that will display next month.

I'm not talking about June 2010 (although since this is may that is next month). I want to have a script that will display a calendar for next month no matter when it is run.

If it is run in February, it will create a calendar for March.
If it is run in June, it will create a calendar for July.
If it is run in December, it will create a calendar for January.

I have tried:

Code:

cal -m `date +"%m"`

but it doesn't like that format (I'm assuming because of the leading zero.

Any suggestions anyone?

yooy · 05-10-2010, 01:08 PM

%M stands for minutes

Coldmiser · 05-10-2010, 01:10 PM

Thanks for catching the typo
Lower case m for months

Tinkster · 05-10-2010, 01:42 PM

Something like this?

Code:

cal -m $(date +"%m %Y" -d "next month")

Coldmiser · 05-10-2010, 02:16 PM

Although that works on Linux, it doesn't seem to work on my Mac where I had intended on using it.
I was hoping there wouldn't be a difference but apparently there is.

Anyway to do this on a Mac?
(Yes, I realize this is LINUXQUESTIONS and not MACQUESTIONS but I can hope for an answer right?)

Tinkster · 05-10-2010, 02:22 PM

Not knowing how or why it's failing on your Mac I cannot answer this.
But I'm moving the question over to "Other *Nix" since it doesn't
belong here for obvious reasons.

Cheers,
Tink

Coldmiser · 05-10-2010, 02:26 PM

Thanks for your help.

Yeah, I should have mentioned that.
When I run the command on my Mac, I'm getting the following errors:

Code:

date: illegal time format
usage: date [-jnu] [-d dst] [-r seconds] [-t west] [-v[+|-]val[ymwdHMS]] ...
            [-f fmt date | [[[mm]dd]HH]MM[[cc]yy][.ss]] [+format]
cal: option requires an argument -- m
usage: cal [-jy] [[month] year]
       cal [-j] [-m month] [year]
       ncal [-Jjpwy] [-s country_code] [[month] year]
       ncal [-Jeo] [year]

Obviously date doesn't like the time format.

anomie · 05-10-2010, 02:39 PM

Break the problem down into two parts. First, you need to focus on getting the numeric value for next month returned. Then you need to feed that value to the cal(1) command.

I won't have access to my OSX box until later today, but this may help in the meantime. (Or, it may be totally useless.)

Code:

# uname 
FreeBSD

# date -v+1m +%m
06

If your date(1) program honors those precise options and formatting, you should be in business. If not, I'll check OSX later.

Coldmiser · 05-10-2010, 03:08 PM

Yup, that was exactly what I needed.
This is the answer to my question:

Code:

cal -m`date -v-1m +"%m"`

Thanks for everyone's help.