CTDP linux 程序员手册 (4.7) 调整时间的程序

datenow=`date +%m%d%Y`

month=`echo $datenow | cut -b1-2`

day=`echo $datenow | cut -b3-4`

year=`echo $datenow | cut -b5-8`

echo $month-$day-$year:$1

days=30

adj=$1

while [ $adj -gt 0 ]

do

case $month in

04 | 06 | 09 | 11 | 4 | 6 | 9)

days=`expr 30`

;;

02 | 2)

days=`expr 28`

;;

* )

days=`expr 31`

;;

esac

if [ $adj -ge $day ]; then

if [ $month -gt 1 ]; then

#         month=`printf "%2d" $(expr $month - 1)`

month=`expr $month - 1`

else

year=`expr $year - 1`

month=12

fi

if [ $adj -ge $days ]; then

adj=`expr $adj - $days`

else

day1=$day

day=`expr $days + $day - $adj`

adj=0

fi

else

day=`expr $day - $adj`

adj=0

fi

if [ `expr length $month` -lt 2 ]; then

month=`echo 0$month`

fi

if [ `expr length $day` -lt 2 ]; then

day=`echo 0$day`

fi

echo $month-$day-$year:$1:$adj

done

echo $month-$day-$year:$1:$adj

yy=`echo $year | cut -b3-4`

echo $month$day"0000"$yy

touch $month$day0000$yy /tmp/time.then