How to convert string(variable) into date( epoch) in ksh on HPUX machine?

Shell Programming and Scripting
1

Hi all,
I have used a bash script which ultimately converts a string into date using date --date option:

 
DATE=$DATE" "$TIME" "`date +%Y` //concatenating 2 strings
TMRW_DATE=`date --date="$DATE" +"%s"` //applying date command on string and getting the unixtime

but i'm not able to convert it into a ksh equivalent.So can anybody help me to do so?

2

What do you exactly mean by ksh equivalent? The date tool that you've used in your bash script is a utility installed on your system running HP-UX, and not a shell feature specific to bash.. You may invoke it from ksh as much you did from bash, if that's what your concern is all about.

3

and that date syntax is specific to your OS... You will need to look at what HP-UX date command proposes and try to figure out what you need...

4

You have posix-sh in your UX - use it or download ksh93

Then you can do using ksh builtin printf , no need for external GNU date.

((day=24*60*60))  
fromdate="04/01/11" 
todate="05/04/11" 
# datestr => epoc 
epoc1=$(printf "%(%#)T" "$fromdate") 
epoc2=$(printf "%(%#)T" "$todate") 
echo $(( (epoc2-epoc1) /day)) 

fromdate="2011-04-01" 
todate="2011-05-04" 
# datestr => epoc 
epoc1=$(printf "%(%#)T" "$fromdate") 
epoc2=$(printf "%(%#)T" "$todate") 
echo $(( (epoc2-epoc1) /day))

Or using some function which give you julian value - works with almost any shell. I have used this set:

#########################################################################
Date2Jul()
{
        oifs="$IFS"
        IFS="-"
        array=($1)
        IFS="$oifs"
        dd=${array[2]}
        mm=${array[1]}
        yyyy=${array[0]}
        ((a= (14-mm)/12 ))
        ((y= yyyy+4800 - a ))
        ((m= mm + 12*a -3 ))
        ((jd= dd + (153*m+2)/5 + 365*y + y/4 - 32083 ))
        echo $jd
}

#########################################################################
Julian2Date()
{
        Xjd="$1"
        Xb=0
        (( Xc=Xjd+32082))
        (( Xd= (4*Xc+3)/1461 ))
        (( Xe= Xc-((1461*Xd)/4)  ))
        (( Xm= (5*Xe+2)/153 ))
        (( Xday= Xe - (153*Xm+2)/5 + 1 ))
        (( Xmonth= Xm + 3 - 12*(Xm/10) ))
        (( Xyear= 100*Xb + Xd - 4800 + Xm/10 ))
        Xdstr="$Xday"
        Xmstr="$Xmonth"
        [ "$Xday" -lt 10 ] && Xdstr="0$Xdstr"
        [ "$Xmonth" -lt 10 ] && Xmstr="0$Xmstr"
        Xjulstr="$Xyear$Xmstr$Xdstr"


        ((Xa= (14-Xmonth)/12 ))
        ((Xy= Xyear - Xa ))
        ((Xm= Xmonth + 12*Xa - 2 ))
        ((Xweekday=  (6 + Xday + Xy + Xy/4 + (31*Xm)/12 ) % 7  ))
        ((Xday<10)) && Xday="0$Xday"
        ((Xmonth<10)) && Xmonth="0$Xmonth"
        echo "$Xjd $Xdstr $Xmstr $Xyear $Xweekday $Xjulstr"
}

######################

        # yyyy-mm-dd 
        [ "$#" -lt 1 ] && echo "usage:$0 yyyy-mm-dd" >&2 && exit 1
        datestr="$1"

        julian=$(Date2Jul "$datestr")
        Julian2Date "$julian" | read julian2 d m y dayOfWeek yyyymmdd
        echo "$julian: $d.$m.$y "
        echo "weekday (mon=1):$dayOfWeek"
        echo "yyyymmdd: $yyyymmdd"
        ((tomorrow=julian+1))
        Julian2Date "$tomorrow" | read julian2 d m y dayOfWeek yyyymmdd
        echo "tomorrow $tomorrow: $d.$m.$y "
5

To be more specific, in bash

TMRW_DATE=`date --date="$DATE" +"%s"`

where 'date --date' is converting the string $DATE into its epoch time (in sec) but in ksh there is no such option with date.

As another limitation I can't download ksh93 or any higher version.I'm currently having ksh88 installed in HPUX machine .If its not possible in ksh script then can i accomplish it using any perl script?

6

@Rashu123: From your first post, what does $DATE, $TIME contain? Please provide sample input and expected output.

7

According to my bash script:

 
DATE=`TZ=IST-24 date |awk -F' ' '{print $2,$3}'`
 echo $DATE
 TIME="10:00:00 IST"
DATE1=$DATE" "$TIME" "`date +%Y`
echo $DATE1
TMRW_DATE=`date --date="$DATE1" +"%s"`
echo $TMRW_DATE

gives output as:

Sep 19
Sep 19 10:00:00 IST 2012
1348029000

So how implement it in ksh or perl ?

8

I'm not sure if you understood post #2 and post #3.

In perl, you may use the timelocal routine from Time::Local module to get the time in seconds since epoch. Check the perldocs for instructions on how to implement the same.