SUMMARY: seconds since Jan 1970 00:00:00

From: Sugan Moodley (suganm@is.co.za)
Date: Fri Apr 07 2000 - 07:34:11 CDT

Thanks to:

Charles Seeger
Bryan Mawhinney
Xaniotakis Vaggelis
Scott D. Yelich
Gerhard den Hollander
Neil Clifford
David Mitchell
Michael F Gordon
Delaney, Ray (FUSA)

My original question was:

---------------------------
Hello,

I was wondering if there was a way, without coding, that one can calculate the seconds since 1 Jan 1970, 00:00:00 till present. This is preferably on Solaris 2.6 I've checked the date command but the GNU version only supports this.

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Most replies were that I should use perl(_UNFORTUNATELY_ not allowed on this
production box):

 perl -e 'print time, "\n"'

However Charles Seeger had THIS to say:

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On Solaris you can use truss like this (sh/ksh syntax):

        set -- `truss -t time date 2>&1 >/dev/null`
        while [ $# -gt 1 ]; do shift ; done
        TIME=$1

Or, if you have perl:

        TIME=`perl -e '$val=time; print -- "$val\n"'`

More portable, though more complicated, sh and ksh versions:

        set -- `env LC_ALL=C LC_TIME=C LANG=C date -u '+%Y %j %H %M %S'`
        DAYS=`expr 365 \* \( $1 - 1970 \) + \( $1 - 1969 \) / 4 + $2 - 1`
        # XXX This will begin to fail in 2100 A.D. unless the following line
        # XXX that adjusts for 100 and 400 years periods is uncommented.
        #[ $1 -gt 2100 ] && DAYS=`expr $DAYS - \( $1 - 2000 \) / 100 \
        # + \( $1 - 2000 \) / 400`
        TIME=`expr $5 + 60 \* \( $4 + 60 \* \( $3 + 24 \* $DAYS \) \)`

        set -- $(env LC_ALL=C LC_TIME=C LANG=C date -u '+%Y %j %H %M %S')
        DAYS=$(( 365*($1 - 1970) + ($1 - 1969)/4 + $2 -1 ))
        # This will begin to fail in 2100 A.D. unless the following line
        # that adjusts for 100 and 400 year periods is uncommented.
        #(( $1 >= 2100 )) && DAYS=$(( $DAYS - ($1-2000)/100 + ($1-2000)/400 ))
        TIME=$(( $5 + 60*($4 + 60*($3 + 24*$DAYS)) ))

FWIW, I originally figured out the sh version about five years ago to
set the LASTCHG field in the shadow password file during jumpstarts.

HTH,
Chuck
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-- 
Sugan Moodley
The Internet Solutions, Rosebank, Gauteng, South Africa.
+27 11 283 5500

The mosquito is the state bird of New Jersey.
		-- Andy Warhol

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