用date取昨天日期

计算昨天日期的bash例子

timestr="3 hours ago"

if [ $mode = "all" ]

then

if [ $# -ge 4 ]

then

curyear=

curmonth=

else

curyear=`date +%Y -d "$timestr"`

curmonth=`date +%m -d "$timestr"`

fi

subname=$curyear-$curmonth

else

if [ $# -ge 5 ]

then

curyear=

curmonth=

curday=

else

curyear=`date +%Y -d "$timestr"`

curmonth=`date +%m -d "$timestr"`

curday=`date +%d -d "$timestr"`

fi

subname=$curyear-$curmonth-$curday

fi