hex2dec() {
    obase=1000000000    # 1e9, the largest power of 10 that fits in int32_t
    ibase=$((1 << 7*4)) # only 7 hex digits, because 0xFFFFFFFF > 1e9

    inp="000000${1#0x}"                 # input value in $1 with optional 0x
    inp=${inp:$((${#inp}%7)):${#inp}}   # pad the string length to a multiple of 7

    carry=0
    # workaround, since sh and ash don't support arrays
    result0=0       # the output value's digits will be stored in resultX variables in little endian
    MSDindex=0      # index of the most significant digit in the result

    print_result()
    {
        eval echo -n \$result$MSDindex  # print MSD
        if [ $MSDindex -gt 0 ]; then    # print remaining digits
            for i in $(seq $((MSDindex-1)) -1 0); do eval printf "%09d" \$result$i; done
        fi
        echo
    }

    # Multiply a digit with the result
    # $1 contains the value to multiply with the result array
    mul()
    {
        carry=0
        for i in $(seq 0 $MSDindex); do
            eval let res="$1\\*result$i+carry"
            eval let result$i=res%obase
            let carry=res/obase
        done
        
        while [ $carry -ne 0 ]; do
            let MSDindex=MSDindex+1
            eval let result$MSDindex=carry%obase
            let carry=carry/obase
        done
    }

    # Add a digit with the result
    # $1 contains the digit to add with the array
    add()
    {
        eval let res=$1+result0
        eval let result0=res%obase
        let carry=res/obase
        
        i=1
        while [ $carry -ne 0 ]
        do
            eval let res=carry+result$i
            eval let result$i=res%obase
            let carry=res/obase
            if [ $i -gt $MSDindex ]; then MSDindex=$i; fi
            let i=i+1
        done
    }

    # main conversion loop
    while [ -n "$inp" ]     # iterate through the hex digits, 7 at a time
    do
        hexdigit=${inp:0:7}
        mul $ibase          # result = result*input_base+hexdigit
        add 0x$hexdigit
        
        if [ ${#inp} -gt 7 ]; then
            inp=${inp: $((7-${#inp}))}
        else
            unset inp
        fi
    done

    print_result
}

valuelist="15ABC12345AFDA325
1AAAAAAAF12233445566778DFEF
1AAFDDAEBCAAAAAF12233445566778DFEF
1AF12233445566778DFEF
1DAF5ABC12345AFDA325
1F12233445566778DFEF
2111111111111111DDDAFC
2111137875433111111DDDAFC
23513A123111111111111111DDDAFC
2A111111111111111DDDAFC
2A123111111111111111DDDAFC
361037073401E5313436BA5C23513A123111111111111111DDDAFC
361037073401E5313436BA5C23513A12311BDEF111DDDAFC
445313436BA5C23513A123111111111111111DDDAFC
445313436BA5C23513A1231111187644211111DDDAFC
44FE5313436BA5C23513A123111111111111111DDDAFC
44FE5313436BA5C23513A12311123466311111DDDAFC
46BA5C23513A123111111111111111DDDAFC
6763610370734013644FE5313436BA5C23513A123111111111111111DDDAFC
676361037073401E5313436BA5C23513A123111111111111111DDDAFC
70734013644FE5313436BA5C23513A123111111111111111DDDAFC
AEF1DADFEBCA32FD32DA325
AEF1DAF5ABC12345AFDA325
BA5C23513A123116541314111111DDDAFC
BA5C23513A123111111111111111DDDAFC
BC23513A123111111111111111DDDAFC"

while read -r v; do
    bc_res=$(echo "ibase=16; $v" | bc | tr -d '\\' | tr -d "\n")
    hex2dec_res=$(hex2dec $v)
    perl_res=$(perl -Mbignum -le "print hex '$v'")
    python_res=$(python -c "print int('$v', 16)")
    gawkbignum_res=$(gawk --bignum -v n=0x$v 'BEGIN {print strtonum(n)}')
    gawk_res=$(gawk -v n=0x$v 'BEGIN {print strtonum(n)}')
    
    echo -ne "\n----------- $v:"
    echo -ne "\n            bc: $bc_res"
    echo -ne "\n       hex2dec: $hex2dec_res $(if [[ $hex2dec_res != $bc_res ]]; then echo -n "x"; fi)"
    echo -ne "\n          perl: $perl_res $(if [[ $perl_res != $bc_res ]]; then echo -n "x"; fi)"
    echo -ne "\n        python: $python_res $(if [[ $python_res != $bc_res ]]; then echo -n "x"; fi)"
    echo -ne "\n    gawkbignum: $gawkbignum_res $(if [[ $gawkbignum_res != $bc_res ]]; then echo -n "x"; fi)"
    echo -ne "\n          gawk: $gawk_res $(if [[ $gawk_res != $bc_res ]]; then echo -n "x"; fi)"
    echo
done <<< "$valuelist"