Shell Programming and Scripting

#!/bin/sh
DB2support_path=/db2support

#Need to compress the month folder in /db2support if it is more than 2 months old
# File name is like Jan-2010

#Caculate the month and year of the directory that is two months old
dy=`date +%j`
yy=`date +%Y`
y1=`expr $yy - 1`
dd=`expr $dy + $y1 \* 365 + $y1 / 4 - $y1 / 100 + $y1 / 400`
d=`expr $dd - 60`
y1=`expr $d \* 400 / 146097`
y=`expr $y1 + 1`
d=`expr $d - $y1 \* 365 - $y1 / 4 + $y1 / 100 - $y1 / 400`
l=`expr \( $y % 4 \| $y % 100 = 0 \& $y % 400 \) = 0`
d=`expr $d + \( $d \> 59 + $l \) \* \( 2 - $l \)`
m=`expr \( $d + 183 \) \* 12 / 367`
d=`expr $d + 183 - $m \* 367 / 12`
m=`expr \( $m + 6 \) % 12 + 1`
FMONTH=$m
  case $FMONTH in
    "1") FMONTH=Jan ;;
    "2") FMONTH=Feb ;;
    "3") FMONTH=Mar ;;
    "4") FMONTH=Apr ;;
    "5") FMONTH=May ;;
    "6") FMONTH=Jun ;;
    "7") FMONTH=Jul ;;
    "8") FMONTH=Aug ;;
    "9") FMONTH=Sep ;;
    "10") FMONTH=Oct ;;
    "11") FMONTH=Nov ;;
    "12") FMONTH=Dec ;;
  esac

tar_dir=$FMONTH-$y
tar_name=$tar_dir".tar"
gz_name=$tar_name".gz"

# tar the directory that is calculated
tar -cvf $DB2support_path/$tar_name $DB2support_path/$tar_dir
# gzip the tar
gzip $DB2support_path/$tar_name

# check to see if the gzip exists and then remove the original directory
if [ -f $DB2support_path/$gz_name ]
 then
  rm -rf $DB2support_path/$tar_dir
fi