Converting TXP to binary and vice versa using shell utilities only

txp.sh

#! /bin/sh

txpToBin() {
        # filter "1 or 3 or ,"
        # insert linebreak after every second ","
        # remove comma
        # append "3" if missing (this can only match the last line)
        # translate 13->0 and 31->1
        # join all lines to one string
        echo $TXP | sed 's/[^1,3,\,]*//g' | sed -e's/\(\([^,]*,\)\{1\}[^,]*\),/\1\n/g' | tr -d ',' | sed ':a;/.\{2\}/!{s/$/3/;ba}' | sed 's/13/0/g;s/31/1/g' | sed ':a;N;$!ba;s/\n//g'
}

binToTxp() {
        # filter "0 or 1"
        # translate 1->X and 0->-
        # translate X->31 and -->13
        # insert comma after each character
        echo "$BIN" | sed 's/[^0-1]*//g' | sed 's/1/X/g;s/0/-/g' | sed 's/X/31/g;s/-/13/g' | sed ':a;s/\B[0-9]\>/,&/;ta'
}

# convert a TXP string into its binary representation (odd length)
TXP="3,1,3,1,1,3,3,1,1,3,3,1,1,3,3,1,1,3,3,1,1,3,3,1,3,1,3,1,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,3,1,3,1,1"
BIN=`txpToBin`
echo "$TXP"
echo "$BIN"
echo

# convert a TXP string into its binary representation (even length)
TXP="$TXP,3"
BIN=`txpToBin`
echo "$TXP"
echo "$BIN"
echo



# convert a binary string into its TXP representation
TXP=`binToTxp`
echo "$BIN"
echo "$TXP"
echo