:
##########################################################################
# Title      :	currencycvt - convert currencies
# Author     :	Heiner Steven <heiner.steven@odn.de>
# Date       :	2002-08-06
# Requires   :	wget, urlencode
# Category   :	WWW, Desktop
# SCCS-Id.   :	@(#) currencycvt	1.6 07/04/18
##########################################################################
# Description
#
##########################################################################

PN=`basename "$0"`			# Program name
VER='1.6'

: ${GETURL:=wget}
: ${GETURLFLAGS="-q -O-"}

: ${AWK:=awk}

CurrencyListURL=http://www.oanda.com/convert/classic
CurrencyListCache=/tmp/$PN.cache

# The following URL may contain the variables $incode, $outcode, $value, and
# $date which will be replaced with the values the user specified

CurrencyConvertURL='http://www.oanda.com/convert/classic?value=$value&exch=$incode&expr=$outcode&date=$date'

FROMCODE=USD				# Defaults
TOCODE=EUR

today=`date +%m/%d/%y`

Usage () {
    echo >&2 "$PN - convert currencies, $VER
usage: $PN [-i fromcode] [-o tocode] [-d date] [amount ...]
   or  $PN searchpattern

options:
    -i:  input currency code (default $FROMCODE)
    -o:  output currency code (default $TOCODE)
    -d:  date in the format YYYY-MM-DD (default: today)

The first usage converts the given amount (default: 1) from
the input currency into the output currency.

The second form is used to look up currency codes: the searchpattern
is assumed to be the name of a country or a currency.

This script uses the excellent service of OANDA.com:
	$CurrencyListURL"
    exit 1
}

Msg () {
    for MsgLine
    do echo "$PN: $MsgLine" >&2
    done
}

Fatal () { Msg "$@"; exit 1; }

# canonws - "canonical" white space
# replace sequences of tab and blank characters with one blank
canonws () {
    sed 's/	/ /g; s/  */ /g; s/^ *//; s/ $//' "$@"
}

GetCurrencyList () {
    if [ -s "$CurrencyListCache" ]
    then				# Use cached version
    	cat "$CurrencyListCache"
    else
    	Msg "retrieving currency list (will be saved in $CurrencyListCache)"

	# The complicated looking "sed" expressions search for HTML code
	# of the form <option value="EUR">...</a> with all possibilities
	# of character case and white space.

	"$GETURL" $GETURLFLAGS "$CurrencyListURL" |
	    sed -n -e '/[ 	]*<[oO][pP][tT][iI][oO][nN][ 	][ 	]*[vV][aA][lL][uU][eE][ 	]*=[ 	]*"*[A-Z][A-Z][A-Z]"*[^>]*>/{s/.*<[oO][pP][tT][iI][oO][nN][ 	][ 	]*[vV][aA][lL][uU][eE][ 	]*=[ 	]*"*\([A-Z][A-Z][A-Z]\)"*.*>\(.*\)/\1	\2/;p;}' |
	    sed 's/[ 	]*\.[ 	]*[A-Z][A-Z][A-Z][ 	
]*$//g;s/^[ 	]*//;s/[ 	]*$//' |
	    # Print each currency code once
	    "$AWK" -F'	' '
		{ n [$1] = $2 }
		END { for (c in n) print c "	" n[c] }
	    ' |
	    sort -u |
	    tee "$CurrencyListCache" |
	    grep .  ||
		Fatal "could not retrieve currency list: $CurrencyListURL"
    fi
}

ConvertCurrency () {
    [ $# -ge 2 ] || Fatal "usage: ConvertCurrency in out"

    incode=`echo "$1" | urlencode`
    outcode=`echo "$2" | urlencode`
    value=`echo "${3:-1}" | urlencode`

    # Quote ampersant ("&") characters within the URL for the subsequent
    # "eval". This is a constant string, so we only want to do it once.

    [ -z "$urlprocessed" ] &&
    	urlprocessed=`echo "$CurrencyConvertURL" | sed 's/&/\\\&/g'`

    eval "urlencoded=$urlprocessed"

    "$GETURL" $GETURLFLAGS "$urlencoded" |
    	canonws |
	egrep '<[a-zA-Z][a-zA-Z]* .*="*result_val"*[^>]*>' |
	striphtml |
	awk '
	    {
	    	for (col = 1; col < NF; col++) {
		    if ($col == "=") {
		    	print $(col + 1)
			break
		    }
		}
	    }
	'
	return 0
}

set -- `getopt :hd:i:o: "$@" || exit 1` || Usage
[ $# -lt 1 ] && Usage			# "getopt" detected an error

while [ $# -gt 0 ]
do
    case "$1" in
    	-d)
	    case "$2" in
	    	[12][0-9][0-9][0-9]-[0-1][0-9]-[0-3][0-9])
		    Date=`echo "$2" | awk -F- '{printf ("%02d/%02d/%02d", \
		    	    $2,$3,$1 % 100) }'`;;
		*)  Fatal "date not in YYYY-MM-DD format: $2";;
	    esac
	    shift;;
    	-i)	InCur=$2; shift;;
	-o)	OutCur=$2; shift;;
	--)	shift; break;;
	-h)	Usage;;
	-*)	Usage;;
	*)	break;;			# First file name
    esac
    shift
done

: ${InCur:=$FROMCODE}
: ${OutCur:=$TOCODE}
: ${Date:=$today}

[ $# -lt 1 ] && set -- 1

date=$Date
for key
do
    case "$key" in
    	*[!0-9.,]*)		# no valid number: country or currency name
	    #echo >&2 "DEBUG: country name: $key"

	    # At first check if the key is a valid currency code. If that
	    # fails, check for a country / currency name.

	    GetCurrencyList |
	    	egrep "^$key	" ||
		GetCurrencyList |
		    egrep -i "$key" |
		    grep . || Fatal "no country or currency matching \"$key\""
	    ;;

	*)
	    #echo >&2 "DEBUG: denomination: $key"
	    converted=`ConvertCurrency "$InCur" "$OutCur" "$key"`
	    [ -n "$converted" ] ||
	    	Fatal "could not convert $key $InCur to $OutCur"
	    echo "$key $InCur = $converted $OutCur"
	    ;;
    esac
done