Get Yesterday's Date [Scripting]

Here is a useful snippet that you can include in your shell scripts if you need to find out what the previous day's date was.

Perl code:

$secsInADay=86400;
@yest=localtime(time-86400);
$year=$yest[5]+1900;
$month=$yest[4]+1;
$day=$yest[3];
print "$year$month$day";

One-liner for Shell Scripts

YEST=`perl -w -e '@yest=localtime(time-86400);printf "%d%.2d%.2d",$yest[5]+1900,$yest[4]+1,$yest[3];'`
echo $YEST

To get Tomorrow's Date

TOM=`perl -w -e '@tom=localtime(time+86400);printf "%d%.2d%.2d",$tom[5]+1900,$tom[4]+1,$tom[3];'`
echo $TOM