Date subtraction in Korn shell scripting

[macrun95]

I was wondering if there is an easy way to subtract one day from the current date? I've found some old shell scripts online that convert to Julian, subtract, and then convert back to Gregorian. That seems like a lot of work and if there is an easier way to do it, that would be great. I need to copy a file from one directory to another with yesterday's date and need to search for that file and copy it. The format is IDXMS-MSY-031708T0601.RPT.

Thanks,
Eric

 

[columb]

PHV's excellent faq80-4800 will help here.

On the internet no one knows you're a dog

Columb Healy

 

[columb]

To elaborate from my earlier posting try

#!/bin/ksh

#GetDate function from PHV's FAQ
GetDate(){ # GetDate nDays [format]
  typeset -i nDays=$1; format=$2
  eval $(echo $TZ | sed '
s!\([^-0-9]*\)\([-0-9]*\)\(.*\)!typeset -i localOffset=\2;zon1=\1;zon2=\3!')
  TZ=$zon1$((localOffset-24*nDays))$zon2 date $format
}

#Find files in source dir with yesterday's date and move them to object dir
find /source/dir -name "IDXMS-MSY-$(GetDate 1 +%m%d%y)*" -exec mv {} /object/dir \;

On the internet no one knows you're a dog

Columb Healy

 

[TunaAdmiral]

This fellow wrote a WONDERFUL script named "datecalc". I use it in many of my scripts. EASY to use!

http://www.unix.com/unix-dummies-questions-answers/4870-days-elapsed-between-2-dates.html#post16559

 

[macrun95]

Thanks for the help. I will look at the datecalc script and see if it will help with what I need. The one from columb worked really well. I tested it on my test lpar with all different kinds of dates and it worked every time.

Thanks again!



Eric