[Chapter 40] 40.10 nextday, nextweekday: Tomorrow or Next Weekday

40.10 nextday, nextweekday: Tomorrow or Next Weekday

nextday	Before my UNIX systems had personal crontabs ( 40.12 ) , I wanted a way to make an at job ( 40.3 ) repeat itself the next weekday (skipping Saturday and Sunday) or, sometimes, every day. Our at was simple-minded and didn't understand dates like now + 1 day . This script with two names, nextday and nextweekday , did the job. I called it from inside my at job, like this:

`...`	% `cat atjob` `somecommand` sleep 60 at 2325 `nextweekday` < atjob

On Thursday, the result will be a command like at 2325 Friday atjob . On Friday, the command will be at 2325 Monday atjob ; using nextday instead, the result would be at 2325 Saturday atjob .

The -n option returns a numeric weekday.

NOTE: This script only works with some versions of date . If your version doesn't understand format strings like +% format , install the date ( 51.10 ) from the CD-ROM.

You can install this script from the CD-ROM or from the online archive ( 52.7 ) . If you get it from the archive, ask tar to install nextday and its other link:

% 

tar xvf 



archive.tar



 nextday nextweekday


x nextday, 1564 bytes, 4 tape blocks
nextweekday linked to nextday

The script tests the name it was called with, in $0 , to decide which command to run.

- JP