#!/bin/bash

# Currency conversion rates list generator.
# Uses data from units_cur and ISO currency code table to format currency rates.
#
# By The Free Thinker, 2020.
# V. 1
# TODO (maybe): Generate currency lists for multiple base currencies.

# 1 = Enable generating rates list
LISTENABLE=0
# 1 = Enable generating gophermaps and directories
GOPHERENABLE=0

# Files needed for Gopher mode:
# menuhead.txt - prepended to currency menu gophermap
# gopherconvert.sh - Script that is sourced by gophermap scripts in currency directory to perform
#                    conversion and format output. Called with parameters for currency conversion.
#                     - Script location is specified below.
# [CUR]/head.txt - File in each currency directory with a custom header prepended to currency output.
#                  Generated by script to state currency name and code, if not already existant.
#

# TODO - Override above with command-line options?

#Path to gopherconvert.sh script:
GOPHERCONVSCRIPT="/home/freet/scripts/currconv/gopherconvert.sh"

# URL for fetching currency name file in [code],[name] format:
CURRENCYNAMEURL="https://raw.githubusercontent.com/umpirsky/currency-list/master/data/en_AU/currency.csv"
UPDATENAMES=1

#Number of decimal places that rate change is shown to:
CHANGESCALE=6

# Set to "0" to be quiet:
VERBOSITY=1

#Custom Currency Array (for currencies without official ISO 4217 code)
#Format is: '[code],"[name]",[ID]\n'
# [code] is a 3-letter code to stand in for an official ISO 4217 currency code.
# [name] is the display name of the currency, quote to include spaces, can't contain ",".
# [ID] is the identifier used in currency.units.
declare -a CUSTOMCURR=(\
'XBT,"Bitcoin (BTC/XBT)",bitcoin\n'\
)
#############################################################
#################### END OF CONFIGURATION ###################
#############################################################

#CURRRATE Arrays:
declare -a CURRRATE     #Conversion rate        eg. "0.40810863746164"
declare -a CURRRATEID   #Currency identifier    eg. "tongapa'anga"
declare -a CURRRATECODE #Base currency          eg. "euro"

#CURRID Arrays:
declare -a CURRID       #Currency identifier    eg. "tongapa'anga"
declare -a CURRIDCODE   #ISO 4217 currency code eg. "TOP"

OLDIFS=$IFS

### Process command-line options (currently just for convert option):
if [ "$1" == "convert" ]
then
CONVERT=1
LISTENABLE=0 # Disable currency list output whenever doing a conversion
GOPHERENABLE=0 # Also disable Gopher stuff
CONVAMOUNT="`expr "$2" : '\([0-9]*\|[0-9]*\.[0-9]*\)[a-zA-Z]*'`"
if [ $? -gt 0 ]
then
 echo -e "ERROR: Invalid Input Amount\n\
Usage is: currencyconv.sh [convert [amount][input 3-letter currency code] [output 3-letter currency code] ]"
 exit 1
fi
CONVINCODE="`echo ${2:(-3)} | tr '[:lower:]' '[:upper:]'`"
CONVOUTCODE="`echo $3 | tr '[:lower:]' '[:upper:]'`"
echo -e "From: $CONVINCODE\nTo: $CONVOUTCODE"

elif [ "$1" ]
then
echo -e "ERROR: Option not recognised.\n\
Usage is: currencyconv.sh [convert [amount][input 3-letter currency code] [output 3-letter currency code] ]"
exit 1
else
CONVERT=0
fi


### Download latest currency names file if it has changed:
####TODO: Handle 404, etc., errors.
if [ $UPDATENAMES -gt 0 ]
then
[ $VERBOSITY -gt 0 ] && echo "Checking for updated currency names..."
if [ ! -e currency.names.etag ]
then
 [ $VERBOSITY -gt 0 ] && echo "Can not find etag file - First run?"
 wget -q -S -O currency.names $CURRENCYNAMEURL 2>&1 | sed -n 's/ *ETag: \(.*\)$/\1/p' > currency.names.etag
else
 ETAG="`cat currency.names.etag`"
 wget -v -S -O currency.names.new --header="If-None-Match: $ETAG" $CURRENCYNAMEURL 2>&1 | sed -n 's/ *ETag: \(.*\)$/\1/p' > currency.names.etag
 if [ -s currency.names.new ]
 then
  [ $VERBOSITY -gt 0 ] && echo "Currency names updated."
  mv currency.names.new currency.names
 fi
fi
fi

IFS=","
###Add custom currencies to start of CURRID arrays:
for (( COUNT = 0 ; COUNT < ${#CUSTOMCURR[*]} ; COUNT++ ))
do
CURRID[COUNT]="`echo -n -e "${CUSTOMCURR[COUNT]}" | cut -d "," -f 3`"
CURRIDCODE[COUNT]="`echo -n -e "${CUSTOMCURR[COUNT]}" | cut -d "," -f 1`"
done

IFS=" "
### Read currency codes from Units rates file
grep -E '^[A-Z]{3} +[a-zA-Z$]+$' currency.units > currency.units.tmp
exec 3<> currency.units.tmp
while read -r CODE ID <&3
do
CURRID[COUNT]="$ID"
CURRIDCODE[COUNT]="$CODE"
(( COUNT++ ))
done
exec 3>&-

### Read currency rates from Units rates file
COUNT=0
grep -E '^[a-z]+ +[0-9]' currency.units > currency.units.tmp
exec 3<> currency.units.tmp
while read -r ID RATE CODE <&3
do
#Convert rate from scientific notation to suit bc (eg. "e-05" = "*10^05")
# Copied from: https://stackoverflow.com/questions/12882611/how-to-get-bc-to-handle-numbers-in-scientific-aka-exponential-notation
RATE=${RATE/e/*10^}; RATE=${RATE/^+/^} #Don't really know if the e+[num] form will crop up, playing safe.

if [[ "$RATE" == 1'|'* ]]; then
 RATE="`expr "$RATE" : '.*|\([0-9.]*\)'`" #Strip "1|" bit from rate string
 RATE="`echo "scale=15; 1 / $RATE" | bc`" #Divide by one using bc (supports floating point calculations)
fi
CURRRATEID[COUNT]="$ID"
CURRRATE[COUNT]="$RATE"
CURRRATECODE[COUNT]="$CODE"
(( COUNT++ ))
done
exec 3>&-
rm currency.units.tmp

if [ $LISTENABLE -gt 0 ]
then
# Output Units rates file update time
echo -n "Currency data last updated" >  currencyrates.new
grep -E -o ' on [0-9]{4}-[0-9]{2}-[0-9]{2}$' currency.units >> currencyrates.new
echo >> currencyrates.new
elif [ $CONVERT -gt 0 ]
then
RATESUPDATEDATE="`grep -E -o ' on [0-9]{4}-[0-9]{2}-[0-9]{2}$' currency.units`"
fi

if [ $GOPHERENABLE -gt 0 ]
then
[ -f menuhead.txt ] && cp menuhead.txt gophermap.new || echo "menuhead.txt not found"
# Output Units rates file update time
echo -n "    Currency data last updated" >>  gophermap.new
grep -E -o ' on [0-9]{4}-[0-9]{2}-[0-9]{2}$' currency.units >> gophermap.new
[ -d gopherconvert_links ] && rm -f gopherconvert_links/* || mkdir gopherconvert_links

#Create links to the binaries used by the gopherconvert.sh Bash script that runs in restricted mode
declare -a BIN=( expr tr cat units ) #All commands used that aren't Bash built-ins

for (( i = 0 ; i < ${#BIN[*]} ; i++ ))
do
 LOCATION="`whereis -b ${BIN[i]}`"
 LEN=$[ ${#bin[i]} + 2 ]
 ln -s "`expr \"$LOCATION\" : \".* \(/.*bin/${BIN[i]}\)\"`" gopherconvert_links/
done

rm -f customcurr.csv
for (( i = 0 ; i < ${#CUSTOMCURR[*]} ; i++ ))
do
 echo "${CUSTOMCURR[i]}" >> customcurr.csv
done

# ln -s "$GOPHERCONVSCRIPT" gopherconvert_links/gophermap # -- Gophernicus can't figure links out
fi


### Read currency names and produce output
#### TODO: Optimise to avoid checking IDs that have already been matched.
[ $VERBOSITY -gt 0 ] && echo -n "Processed: "
LINE=1
IFS=","
echo -n -e "${CUSTOMCURR[*]}" | sort currency.names - | while read -r CODE NAME ID
do
NAME="`echo "$NAME" | tr -d '"'`" # Strip any quotes from around currency name

# Find matching currency code in Units data, to reveal the index number of the ID string
IDCOUNT=0
while [ "${CURRIDCODE[IDCOUNT]}" != "" ] && [ "${CURRIDCODE[IDCOUNT]}" != "$CODE" ] ; do
 (( IDCOUNT++ ))
done

if [ "${CURRIDCODE[IDCOUNT]}" != "" ]
then
 LINE=$[ $LINE + 2 ] #Increment count of lines in currencyrates.new

 # Find currency rate associated with extracted ID string
 RATECOUNT=0
 while [ "${CURRRATEID[RATECOUNT]}" != "${CURRID[IDCOUNT]}" ] && [ $RATECOUNT -lt ${#CURRRATEID[*]} ]
 do
  (( RATECOUNT++ ))
 done

 [ $VERBOSITY -gt 0 ] && echo -n " ${CURRIDCODE[IDCOUNT]} "

 ### Convert currency
 if [ $CONVERT -gt 0 ]
 then
  #Grab the needed data as it passes by:
  if [ "$CODE" == "$CONVINCODE" ]
  then
   CONVINNAME="$NAME"
   CONVINRATE="${CURRRATE[RATECOUNT]}"
   CONVINBASE="${CURRRATECODE[RATECOUNT]}"
   [[ "$CONVINBASE" == "US\$"* ]] && CONVINBASE=USD
  elif [ "$CODE" == "$CONVOUTCODE" ]
  then
   CONVOUTNAME="$NAME"
   CONVOUTRATE="${CURRRATE[RATECOUNT]}"
   CONVOUTBASE="${CURRRATECODE[RATECOUNT]}"
   [[ "$CONVOUTBASE" == "US\$"* ]] && CONVOUTBASE=USD
  fi
  # Once we've got everything, time for some output:
  if [ $CONVINNAME ] && [ $CONVOUTNAME ]
  then
   if [ "$CONVINBASE" != "$CONVOUTBASE" ] && [ "$CONVINBASE" ] && [ "$CONVOUTBASE" ]
   then
    echo -e "\n\nSorry, the currency data uses different base currencies for the currencies that you want to convert \
between, and converting between different base currencies is just too confusing for this poor little script.\n\n\
I'm sure that GNU Units would be happy to help, if you have it handy..." #'
   elif [ "$CONVINCODE" == "$CONVOUTBASE" ]
    then echo -n -e "\n\n  Result: "; printf "%.4f\n" "`echo "scale=15; $CONVAMOUNT / $CONVOUTRATE" | bc`"
   elif [ "$CONVOUTCODE" == "$CONVINBASE" ]
    then echo -n -e "\n\n  Result: "; printf "%.4f\n" "`echo "scale=15; $CONVAMOUNT * $CONVINRATE" | bc`"
   else
    echo -n -e "\n\n  Result: "; printf "%.4f\n" "`echo 'scale=15; ('$CONVAMOUNT' * '$CONVINRATE') / '$CONVOUTRATE | bc`"
   fi
  echo -e "  ------------------------------------------------------------------\n\
Input currency name:  $CONVINNAME\tRATE: $CONVINRATE $CONVINBASE\n\
Output currency name: $CONVOUTNAME\tRATE: $CONVOUTRATE $CONVOUTBASE\n\
Currency rates last updated$RATESUPDATEDATE"
  exit 0
  fi
 fi

 ###Output rates table in alphabetical order of currency codes
 ### Write currency code, name from currency.names, and rate, to currencyrates file:
 if [ $LISTENABLE -gt 0 ]
 then
  CHANGESTRING=

  #Rise/Fall Indicator
  #Output rate change since last run, if currency list (and base currency) not changed:
  if [ -r currencyrates.txt ] && expr "`sed -n "$LINE p" currencyrates.txt`" : "${CURRIDCODE[IDCOUNT]}" > /dev/null #Check currency codes match
  then
   OLDRATE="`sed -n "$[ $LINE + 1 ] p" currencyrates.txt`" # Grab line with currency rate
   if expr "$OLDRATE" : '.*'"${CURRRATECODE[RATECOUNT]}"'.*' > /dev/null # Check that base currencies match
   then
    OLDRATE="`expr "$OLDRATE" : ' *\([0-9.^+*-]*\)'`" #Get old currency rate
    if [ $OLDRATE ] #Base currency won't have a rate number, so skip it.
    then
       # echo "${CURRRATE[RATECOUNT]} - $OLDRATE"
     CHANGE="`printf "%.${CHANGESCALE}f" \`echo "scale=15; ${CURRRATE[RATECOUNT]} - $OLDRATE" | bc\``" #Calculate change in currency rate

     if [ "$CHANGE" == "`printf "%.${CHANGESCALE}f"`" ]
     then #If currency is steady, mark with "-"
      CHANGESTRING='  ( - )'
     else
      #Otherwise mark "^" or "v" depending on whether number is marked negative:
      [[ "$CHANGE" != '-'* ]] && CHANGESTRING='  (^ '$CHANGE')' || CHANGESTRING='  (v '$CHANGE')'
     fi
    fi
   fi
  fi
 #Output line:
 echo -e "${CURRIDCODE[IDCOUNT]} - $NAME:\n       ${CURRRATE[RATECOUNT]} ${CURRRATECODE[RATECOUNT]}$CHANGESTRING" >> currencyrates.new
  # echo -n "Line $LINE: " ; sed -n "$LINE p" currencyrates.txt
 fi

 ###Generate Gophermap and Gopher currency directories
 if [ $GOPHERENABLE -gt 0 ]
 then
  # Create and populate currency directory if it's not already there:
  if [ ! -d "$CODE" ]
  then
   mkdir "$CODE"
   echo -e '#!/bin/bash\nPATH= . '"$GOPHERCONVSCRIPT" > "$CODE/gophermap"
   #echo -e '#!/bin/bash\n. ../gopherconvert.sh $QUERY_STRING' > "$CODE/gophermap" #For old/alternative gopherconvert.sh
   chmod a+rx,go-w "$CODE/gophermap"
   echo -e "   ---   Converted to $NAME ($CODE)   ---   \n" > "$CODE/head.txt"
  fi

  # Copy fresh links to executables used by gopherconvert.sh so that restricted Bash can find them:
  cp -d gopherconvert_links/* "$CODE/"

  # Add currency to menu gophermap:
  echo -e "7$CODE - $NAME:\t$CODE\n       ${CURRRATE[RATECOUNT]} ${CURRRATECODE[RATECOUNT]}$CHANGESTRING" >> gophermap.new
 fi

fi
done

[ $VERBOSITY -gt 0 ] && echo
[ $LISTENABLE -gt 0 ] && mv currencyrates.new currencyrates.txt
[ $GOPHERENABLE -gt 0 ] && mv gophermap.new gophermap
IFS="$OLDIFS"

You are viewing proxied material from aussies.space. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.