Need korn script to get date - 1 1

[Tison]

Does anyone have a script to get yesterdays date (catering for yesterday being last month or even 31 12 yy)?

 

[alexhu]

Checkout faq80-953

Alex

 

[RodKnowlton]

To deal with dates in the shell, it is useful to convert to Julian Day values (

http://www.wikipedia.org/wiki/Julian_day).

The listing below provides two functions for Julian Day conversions that I implemented in KornShell based on C routines appearing in The C Users Journal.

Save the listing to a file, source it ( [tt]. <filename>[/tt] ), and then yesterday's date can be calculated like so:

[tt]
today=$(ToJul `date +&quot;%m %e %Y&quot;`)
(( yesterday = today -1 ))
set `FromJul $yesterday`
month=$1
day=$2
year=$3
echo &quot;$month/$day/$year&quot;
[/tt]

Hope this helps.

**begin script**
[tt]
#!/bin/ksh

# KornShell implementation of Julian Day functions


# ToJul and FromJul functions based on C routines presented by
# David Burki, The C Users Journal, Vol. 11 , No 2, February, 1993,
# page 30.
#
# Burki's algorithm was an adaptation of the FORTRAN code used to
# implement the algorithm presented by H. Fliegl and T. Van Flanders,
# Communications of the ACM, Vol. 11, No. 10, October, 1968, page 657.


function ToJul #month day year
{
# ToJul prints the Julian Day value for the date passed

integer lmonth=${1}
integer lday=${2}
integer lyear=${3}

# set to defaults if null
if [[ ${lmonth}&quot;&quot; -eq &quot;&quot; ]]
then
lmonth=$(date +&quot;%m&quot
fi

if [[ ${lday}&quot;&quot; -eq &quot;&quot; ]]
then
lday=$(date +&quot;%d&quot
fi

if [[ ${lyear}&quot;&quot; -eq &quot;&quot; ]]
then
lyear=$(date +&quot;%Y&quot
fi


jul_day=$(( lday - 32075 + 1461 *
(lyear + 4800 + (lmonth - 14) /12) /
4 + 367 * (lmonth - 2 - (lmonth -14) /
12 * 12 ) / 12 - 3 * ((lyear + 4900 +
(lmonth - 14) / 12 ) / 100) /4 ))

echo ${jul_day}
}


function FromJul #julian_day
{
# FromJul prints the date represented by the passed Julian Day value in the
# form &quot;month day year&quot;

integer t1
integer t2
integer yr
integer mo

integer jul_date=${1}
integer month
integer day
integer year

t1=$((jul_date + 68569))
t2=$(( 4 * t1 / 146097 ))
t1=$(( t1 - (146097 * t2 + 3)/4))
yr=$(( 4000 * ( t1 + 1) /1461001 ))
t1=$(( t1 - 1461 * yr /4 + 31 ))
mo=$(( 80 * t1 / 2447 ))
day=$(( t1 - 2447 * mo / 80 ))
t1=$(( mo / 11 ))
month=$(( mo + 2 - 12 * t1 ))
year=$(( 100 * (t2 - 49) + yr + t1 ))
echo &quot;${month} ${day} ${year}&quot;
}

function DayOfWeek #julian_day
{
integer julian_day=${1}
echo $(( julian_day % 7 ))
}
[/tt]
**end script**

Rod Knowlton
IBM Certified Advanced Technical Expert pSeries and AIX 5L

 

[MoshiachNow]

That's what I have used to establish the date 1 week back in the format that errpt uses:
===================================

#Establish the date 1 week back in the format of errpt:
CURRENT_DATE=`date +%m%d%H%M%y`
integer MONTH=`echo $CURRENT_DATE |cut -c 1-2`
integer DAY=`echo $CURRENT_DATE |cut -c 3-4`
REMINDER=`echo $CURRENT_DATE |cut -c 5-10`
MONTH=$MONTH+12
if (( ($DAY + 23) <= 30 )) ;then
(( DAY=$DAY+23 ))
(( MONTH=$MONTH-13 ))
else
(( DAY=$DAY-7 ))
(( MONTH=$MONTH-12 ))
fi
if (( $MONTH ==0 )) ;then
MONTH_S=”12”
elif (( $MONTH <= 9 )) ;then
MONTH_S=&quot;0$MONTH&quot;
else
MONTH_S=$MONTH
fi
if (( $DAY <= 9 )) ;then
DAY_S=&quot;0$DAY&quot;
else
DAY_S=$DAY
fi


&quot;Long live king Moshiach !&quot;

http://www.7for70.com/

 

[Yegolev]

star for Rod... even though i use perl for such things. =)

IBM Certified -- AIX 4.3 Obfuscation

 

[RodKnowlton]

Thanks, Yegolev.

Perl's my choice these days, as well.

That script was so dusty, I'm suprised it didn't clog my net connection.



Rod Knowlton
IBM Certified Advanced Technical Expert pSeries and AIX 5L

 

[denisfo]

the most simple solution :
imagine you're in GMT-2

do the following :

export OLDTZ=$TZ
export TZ=GMT+22 # (-2 + 24) (if your're in GMT+6 do GMT+30)
DATE=`date`
export TZ=$OLDTZ

#this tip allow your to decrease or increase minutes too. (by GMT-2:30 you'll decrase time by 30 min)