1 Hour less

UNIX for Beginners Q & A UNIX for Dummies Questions & Answers
1

set DAY=`date +%y%m%d`
set H=`date +%H`
set M=`date +%M`

mailx -s "$H-Mydata" myemail@mail.com<mydata

I am looking to set the current hour to have 1 hour less in the subject header:

For example: let's say the system time is 8

I want to have "7-Mydata" not "8-Mydata"

Can some1 helps?

Many thanks!

2

Go into the FAQ and look for datecalc - Perderabo wrote a script to handle time/date arithmetic.

3

let HOUR=$(date +%H)-1
echo ${HOUR}

Works in korn and bash

4

What happens if it is midnight? Would't the HOUR get set to -1?

5

Good question :slight_smile:
Pesky 00's

if (( $(date +%H) < 1 )); then
HOUR=23
else
let HOUR=$(date +%H)-1
fi

6

#!/usr/bin/csh

Thanks!

7

Something like this probably.

#!/bin/csh

if( `date +%H` < 1 ) then
        set HOUR=23
else
        set HOUR=`date +%H`
        set HOUR=`expr $HOUR - 1`
endif
echo $HOUR

But this may not be as elegant of efficient as it should be. I'm no csh scripter.