Shell Programming and Scripting

$ cal
   January 2011
 S  M Tu  W Th  F  S
                   1
 2  3  4  5  6  7  8
 9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31

$ cal 8 2011
   August 2011
 S  M Tu  W Th  F  S
    1  2  3  4  5  6
 7  8  9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

cat /home/unxsa/holiday/holiday.date 

01/01/2011
10/04/2011
13/04/2011
24/05/2011
01/07/2011
02/08/2011
06/09/2011
11/10/2011
11/11/2011
25/12/2011
26/12/2011

./find_business_day 3

./find_business_day 10 8 2011

#! /usr/bin/ksh

Day=$(date +%d)
Month=$(date +%m)
Year=$( date +%Y)
HOLIDAY=/home/unxsa/holiday/holiday.date 
AWK=nawk

usage () {
  echo "Holiday date file at $HOLIDAY"
  echo "Usage: $0 Day [ Month Year ] "
  echo "example: "
  echo "get the 5th business day in current month"
  echo "$0 5 "
  echo "get the 10th bueinsee day on May 2010"
  echo "$0 10 5 2010"
}

if [[ $1 == "" ]]; then
  usage
  exit
else
  Bday=$1
fi

if [[ $3 == "" ]]; then
  CAL="/usr/bin/cal"
else
  Month=$2
  Year=$3
  CAL="/usr/bin/cal $Month $Year"
fi

Blist=$( $CAL |$AWK 'NR>2 {print substr($0,4,14)}' |tr "\n" " ")
$AWK -F \/ -v m=$Month -v y=$Year '$2==m&& $3==y {sub(/^0/,"",$1);print $1}' $HOLIDAY |while read line
do
  Blist=$(echo $Blist |$AWK -v d=$line '{for (i=1;i<=NF;i++) $i=($i==d)?"":$i}1' )
done

echo $Blist |$AWK -v d=$Bday '{print $d}'