日期偏移shell - Chinaunix - Powered by Discuz!

#!/bin/sh

#print information(打印消息)
prn() {
echo $*
}
#print information(打印消息)

#check parameter is number(检查输入是否是数字)
#parameters （参数）
#number that will be checked(要检查的内容)
#[err info](错误信息，可选)
isnum(){
  if [ $# -ge 1 ]; then
ok=`echo $1|sed -n '/^[0-9][0-9]*$/p'`
if [ -n $ok ]; then
   return 0
else
   if [ $# -eq 2 ]; then
      prn $2
   fi
   return 1
fi
  else
return 1
  fi
}
#check parameter is number(检查输入是否是数字)

#get the month's days(得到指定年月的天数)
#parameters（参数）
#year(年)
#month(月)
leap() {
if [ $# -eq 2 ]; then
      case $2 in
      1|3|5|7|8|10|12)
         Max=31
         ;;
      4|6|9|11)
         Max=30
         ;;
      2)
         #div by 4 and not by 100 or div by 400 is leap month(闰年－被4整除不能被100整除；被400整除)
         if [ `rmd $1 4` -eq 0 -a `rmd $1 100` -ne 0 -o  `rmd $1 400` -eq 0 ]; then
            Max=29
         else
            Max=28
         fi
         ;;
      *) Max=0
      esac
      echo $Max
else
   echo 0
fi
}
#get the month's days(得到指定年月的天数)

#add operation(加)
#parameters(参数)
#op1（参数1）
#op2（参数2）
add() {
  echo `expr $1 + $2`
}

#subtration operation(减)
#parameters(参数)
#op1（参数1）
#op2（参数2）
sub() {
  echo `expr $1 - $2`
}

#multiply operation(乘)
#parameters(参数)
#op1（参数1）
#op2（参数2）
mult() {
  echo `expr $1 \* $2`
}

#div operation(除)
#parameters(参数)
#op1（参数1）
#op2（参数2）
div() {
  echo `expr $1 / $2`
}

#remainder operation(余)
#parameters(参数)
#op1（参数1）
#op2（参数2）
rmd() {
  echo `expr $1 % $2`
}

#get lens of string(串长)
#parameters(参数)
#str(串)
strlen() {
  echo `expr $1 : '.*'`
}

#cal time offset（计算偏移时间）
#parameters（参数）
#offset（偏移量，单位为分钟，正数向后偏移，负数向前偏移）
#time（基准时间，如不给出取系统时间）
#note:the offset can not be greate than one month(注：目前只能处理1个月内的偏移)
dayoff() {
  info="syntax: dayoff '30 200306230000',note 30'units is minute or dayoff 30"
  if [ $# -ge 1 ]; then
   #check offset format,offset must be number and it can begin with '+' or '-'
   op=`echo $1|cut -b 1-1`
   len=`expr $1 : '.*'`
   if [ $op != "+" -a $op != "-" ]; then
      op="+"
      off=$1
   else
      off=`echo $1|cut -b 2-$len`
   fi
   isnum $off $info
   if [ $? -ne 0 ]; then
   return 1
   fi

   #check time format,if time param not supply get system time
   if [ $# -eq 2 ]; then
      time=$2
      #get string length and check parameters
      len=`strlen "$time"`
      #check time lenth
      if [ $len -gt 12 ]; then
         prn $info
         return 1
      elif [ $len -lt 12 ]; then
         prn $info
         return 1
      fi
      #check time is num
      isnum $2 $info
      if [ $? -ne 0 ]; then
      return 1
      fi

      #get each part of time
      year=`echo $time | cut -b 1-4`
      month=`echo $time | cut -b 5-6`
      month=`sub $month 0`
      daymax=`leap $year $month`
      day=`echo $time | cut -b 7-8`
      hour=`echo $time | cut -b 9-10`
      minute=`echo $time | cut -b 11-12`
      if [ $month -gt 12 -o $month -lt 1 -o $day -gt $daymax -o $day -lt 1 -o $hour -gt 23  \
      -o $hour -lt 0 -o $minute -gt 59 -o $minute -lt 0 ]; then
         prn "Invalid time range. \n" $info
         return 1
      fi
   else
      year=`date +%Y`
      month=`date +%m`
      month=`sub $month 0`
      daymax=`leap $year $month`
      day=`date +%d`
      hour=`date +%H`
      minute=`date +%M`
   fi
   #get days of the month
   #deal each condition
   #"+"condition
   if [ $op = "+" ]; then
      #get total of minutes
      total=`add  $off  $minute`
      #cal muniute part
      minute=`rmd $total 60`
      #get total of hours
      total=`div $total  60`
      total=`add  $total $hour`
      #cal hour part
      hour=`rmd $total 24`
      #get total of days
      total=`div $total 24`
      days=`add $total $day`
      if [ $days -gt $daymax ]; then
         day=`sub $days $daymax`
         month=`add $month 1`
   else
      day=$days
   fi
   if [ $month -gt 12 ]; then
      year=`add $year 1`
      month=1
   fi
   #"-"condition
   else
   #get total hours of off
   total=`div $off 60`
   #get hour part  of off in minute
   tmp=`mult $total  60`
   #get minute of off
   tmp=`sub $off $tmp`
   #cal minute part
   tmp=`sub $minute  $tmp`
   if [ $tmp -lt 0 ];then
      total=`add $total 1`
      minute=`add $tmp 60`
   else
      minute=$tmp
   fi
   #get total days of off
   tmp=$total
   total=`div $tmp 24`
   tmp1=`mult $total  24`
   tmp=`sub $tmp $tmp1`
   #cal hour part
   tmp=`sub  $hour $tmp`
   if [ $tmp -lt 0 ]; then
      total=`add $total 1`
      hour=`add $tmp 24`
   else
      hour=$tmp
   fi
   #deal days
   tmp=`sub $day $total`
   if [ $tmp -le 0 ]; then
         month=`sub $month 1`
         if [ $month -eq 0 ]; then
            year=`sub $year 1`
            if [ $year -lt 0 ]; then
               prn can not cal BC
               return 1
            fi
            month=12
            day=`add $tmp 31`
         else
            tmp1=`leap $year $month`
            day=`add $tmp $tmp1`
         fi
   else
         day=$tmp
   fi
   fi
   printf "%04d%02d%02d%02d%02d\n" $year $month $day $hour $minute
   return 0
  else
   prn $info
   return 1
  fi
}
#cal time offset（计算偏移时间）