C program not running properly on raspberry pi - c

Question

I'm currently designing a hemming code. This code works perfectly on my computer but when I port it over to my pi, it just does not work properly. I have no idea why and I am pretty new at C and the raspberry pi. Any help would be greatly appreciated.
Below is my full code:
#include <stdio.h>
#include <stdbool.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
int main(void){
int bitLen, errorLoc;
printf("\nLength of the data bits: ");
scanf("%d", &bitLen);
char binStr[ bitLen ], binStrErr[ bitLen ];
printf("Data stream without error: ");
scanf("%s", &binStr);
if(strlen(binStr) > bitLen || strlen(binStr) < bitLen)
{
printf("\nLength of data stream given does not match stated input length!");
return 0;
}
printf("Location of data bit that has error: ");
scanf("%d", &errorLoc);
if(errorLoc > bitLen)
{
printf("\nValue given is bigger than the input length!");
return 0;
}
//Number Of Check Bits Needed
int rBit = 1;
while (pow(2, rBit) < (bitLen + rBit + 1))
{
rBit = rBit + 1;
}
int checkBitsArr[rBit];
int checkBitsErrArr[rBit];
//Actual size of array
bitLen = bitLen + rBit;
int binNum[bitLen];
int binNumErr[bitLen];
int size = sizeof(binNum) / sizeof(binNum[0]);
int binNumPos = size;
printf("\nData stream: ");
//Flipping the error bit and storing into another string
printf("\nOriginal data stream: ");
for (int i = 0; i < strlen(binStr); i++){
printf("%c", binStr[i]);
if(i == (strlen(binStr)) - errorLoc){
int temp = ((binStr[i] - '0') == 0) ? 1 : 0;
binStrErr[i] = temp + '0';
}
else{
binStrErr[i] = binStr[i];
}
}
printf("\nData stream with error: ");
for (int i = 0; i < strlen(binStr); i++){
printf("%c", binStrErr[i]);
}
//Filling in the bits into two arrays: One is the correct data stream and one with error
for (int i = strlen(binStr); i >= 0; i--)
{
binNum[binNumPos] = binStr[i] - '0';
binNumErr[binNumPos] = binStrErr[i] - '0';
binNumPos--;
}
printf("\n\n");
//Moving bits to left to make space
int position = 1;
for (int i = size - 1; i >= 0; i--)
{
if ((position & (position - 1)) == 0)
{
for (int c = 0; c <= i; c++)
{
binNum[c - 1] = binNum[c];
binNumErr[c - 1] = binNumErr[c];
}
binNum[i] = 33;
binNumErr[i] = 33;
}
position++;
}
//Settings check bits into place
position = 1;
int checkBitIndex = 0;
for (int i = size - 1; i >= 0; i--)
{
//Get check bit position
if ((position & (position - 1)) == 0)
{
int temp = 0;//number of 1s in relation to the check bit
int tempErr = 0;
int maxNum = (i - position) + 1;
if (maxNum < 0)
maxNum = maxNum + (-1 * maxNum);
//first part of check
while (maxNum < i)
{
if (binNum[maxNum] == 1)
{
temp++;
}
if (binNumErr[maxNum] == 1)
{
tempErr++;
}
maxNum++;
}
int startNum = (i - position) + 1;
//If the start number is less than zero, make it zero
if (startNum < 0)
startNum = startNum + (-1 * startNum);
//Skip check method. Get the next set of check values in relation to the current check bit
for (int x = startNum - (position * 2); x >= 0; x = x - (position * 2))
{
int k = 0;
while (k < position)
{
if (binNum[x + k] == 1)
{
temp++;
}
if (binNumErr[x + k] == 1)
{
tempErr++;
}
k++;
}
}
//Set the value of check bit
binNum[i] = (temp % 2 == 0) ? 0 : 1;
binNumErr[i] = (tempErr % 2 == 0) ? 0 : 1;
//Replace the current value with the correct checkbit
checkBitsArr[checkBitIndex] = binNum[i];
checkBitsErrArr[checkBitIndex] = binNumErr[i];
temp = 0;
tempErr = 0;
checkBitIndex++;
}
position++;
}
printf("\nSEC code: ");
printf("\nOriginal data stream: ");
for (int i = 0; i < size; i++)
{
printf("%d", binNum[i]);
}
printf("\nData stream with error: ");
for (int i = 0; i < size; i++)
{
printf("%d", binNumErr[i]);
}
printf("\n\n");
int checkIndex = (int)pow(2, rBit - 1);
printf("\n\nCheckbits of data bits without error: \n");
for (int i = checkBitIndex - 1; i >= 0; i--)
{
printf("C%d: %d ", checkIndex, checkBitsArr[i]);
checkIndex = checkIndex/2;
}
checkIndex = (int)pow(2, rBit - 1);
printf("\n\nCheckbits of data bits with error: \n");
for (int i = checkBitIndex - 1; i >= 0; i--)
{
printf("C%d: %d ", checkIndex, checkBitsErrArr[i]);
checkIndex = checkIndex/2;
}
checkIndex = (int)pow(2, rBit - 1);
int posError = 0;
printf("\n\nSyndrome code: \n");
for (int i = checkBitIndex - 1; i >= 0; i--)
{
int x = checkBitsErrArr[i] ^ checkBitsArr[i];
if(x == 1){
posError += checkIndex;
}
printf("C%d: %d ", checkIndex, x);
checkIndex = checkIndex/2;
}
printf("\n\n");
printf("\nPosition of error: %d\n\n", posError);
// printf("\n\n");
return 0;
}
These are the inputs for the scanf:
Length of the data bits: 16
Data stream without error: 0011001100110011
Location of data bit that has error: 8
Below are my results on both computer and pi:
Computer result (correct):
Pi result (wrong):

Answer 1

Looks like you have far more than just one problem, but let's just start with the first one:
char binStr[ bitLen ], binStrErr[ bitLen ];
The string you are requesting next contains not just the 16 bytes you get as input, but also an additional sentinel character as the 17th character.
So at this point you already had 2 buffer overflows, which you can already see nicely in the output from the Pi. The same buffer overflow also occurs in the first example, except the memory layout is different enough so that it doesn't yield visible artifacts.
for (int c = 0; c <= i; c++)
{
binNum[c - 1] = binNum[c];
binNumErr[c - 1] = binNumErr[c];
}
Here comes the next buffer overflow, respectively actually an underflow this time. You are writing to binNum[-1] which is a memory location outside of the memory binNum is pointing to.
Anyway, a buffer overflow means the behavior of your program is undefined.
Get used to valgrind or similar tools for checking your code for undefined with regard to such errors.