# !/bin/sh
# daysold - shell script to show how many days old a given file is
#

# Internal functions
yeardays() {
  # return the number of days in a year
  # usage: yeardays ccyy
  if [ $# = 0 ]
  then
    echo 0
    return
  else
    y=$1
  fi
  # a year is a leap year if it is even divisible by 4
  # but not evenly divisible by 100
  # unless it is evenly divisible by 400
  # if it is evenly divisible by 400 it must be a leap year
  a=`expr $y % 400`
  if [ $a = 0 ]
  then
    echo 366
    return
  fi
  #if it is evenly divisible by 100 it must not be a leap year
  a=`expr $y % 100`
  if [ $a = 0 ]
  then
    echo 365
    return
  fi
  # if it is evenly divisible by 4 it must be a leap year
  a=`expr $y % 4`
  if [ $a = 0 ]
  then
    echo 366
    return
  fi
  # otherwise it is not a leap year
  echo 365
  return
}

getdays() {
  IYear=`echo $1 | cut -c1-4`
  IMonth=`echo $1 |cut -c5-6`
  IDay=`echo $1 |cut -c7-8`
  if [ "${IYear}" = "${SysYear}" ]
  then
    FDays=`date --date $1 +%j`
    DDays=`expr ${JulDate} - ${FDays}`
    echo ${DDays}
    return
  fi
  DaysInFYear=`yeardays ${IYear}`
  IJulian=`date --date $1 +%j`
  FDays=`expr $DaysInFYear - $IJulian`
  # FDays=`expr $FDays + 1`
  YTmp=`expr $IYear + 1`
  while [ $YTmp -lt $SysYear ]
  do
    DTmp=`yeardays $YTmp`
    FDays=`expr $FDays + $DTmp`
    YTmp=`expr $YTmp + 1`
  done
  FDays=`expr $FDays + $JulDate`
  echo $FDays
  return
}

SysDate=`date +%Y%m%d`
JulDate=`date +%j`
SysMonth=`date +%m`
SysYear=`date +%Y`
TmpYear=`date +%Y`
YM=""
for i in 0 1 2 3 4 5 6 7
do
        Tmp=`expr $SysMonth - $i`
        [ ${Tmp} -le 0 ] && {
                Tmp=`expr ${Tmp} + 12`
                TmpYear=`expr ${SysYear} - 1`
        }
        case ${Tmp} in
        1)      TmpMonth="01";;
        2)      TmpMonth="02";;
        3)      TmpMonth="03";;
        4)      TmpMonth="04";;
        5)      TmpMonth="05";;
        6)      TmpMonth="06";;
        7)      TmpMonth="07";;
        8)      TmpMonth="08";;
        9)      TmpMonth="09";;
        10)     TmpMonth="10";;
        11)     TmpMonth="11";;
        12)     TmpMonth="12";;
        *)      echo "Code isn't working.... Exiting."; exit 1;;
        esac
        [ "${YM}" = "" ] && {
                YM="${TmpYear}${TmpMonth}"
                continue
        }
        YM="${YM} ${TmpYear}${TmpMonth}"
done

for Line in `ls -l $* | sed -e 's/ * / /g' -e 's/^ //' | tr " " "#"`
do
        Line="$Line#"
        case $Line in
        tot*) continue;;
        *) ;;
        esac
        File=`echo ${Line} | cut -f9 -d"#"`
        Month=`echo ${Line} | cut -f6 -d"#"`
        case $Month in
        "")     continue;;
        Jan)    MM="01";;
        Feb)    MM="02";;
        Mar)    MM="03";;
        Apr)    MM="04";;
        May)    MM="05";;
        Jun)    MM="06";;
        Jul)    MM="07";;
        Aug)    MM="08";;
        Sep)    MM="09";;
        Oct)    MM="10";;
        Nov)    MM="11";;
        Dec)    MM="12";;
        *)              echo "Invalid Month on file $File. Exiting."
                                exit 1;;
        esac
        Day=`echo ${Line} | cut -f7 -d"#"`
        case ${Day} in
        ?)      Day="0${Day}";;
        *)      ;;
        esac
        Year=`echo ${Line} | cut -f8 -d"#"`
        case ${Year} in
        ??:??)  Year="TIME";;
        *)                      ;;
        esac
        [ "${Year}" = "TIME" ] && {
                for j in ${YM}
                do
                        TmpMonth=`echo $j | cut -c5,6`
                        [ "${MM}" = "${TmpMonth}" ] && {
                                TmpYear=`echo $j | cut -c1-4`
                                Year=${TmpYear}
                                break
                        }
                done
        }
        Tmp="${Year}${MM}${Day}"
        Days=`getdays ${Tmp}`
        echo "$Days $File"
        # debugging area...
        # echo $Tmp
        # echo "YM Conv=${YM}"
        # echo "System Gregorian Date=${SysDate}"
        # echo "System Julian Date=${JulDate}"
        # echo "Month=${MM}"
        # echo "Day=${Day}"
        # echo "Year=${Year}"
        # echo "Days Old = ${Days}"
        # echo $Line
        # echo "FileDate=${Tmp} GetDate=${From}"
        # read ans gbg
done