Return pointer in Main function - C

[Shervan360]

Hello,

How can I fix it? I want to back "12" in the main function with the result pointer and then print it.
The function is worked fine but I have a problem when I want to back result to main a print.
Thanks

#include<stdio.h>
#include <string.h>

void strstrX(char* number1, char* number2, char* result)
{
	int c1 = 0;
	int first = 0;
	while (number1[c1] != '\0')
	{

		c1++;
	}

	int c2 = 0;
	while (number2[c2] != '\0')
	{
		c2++;
	}
	int num1 = 0;
	for (int i = 0; i < c1; i++)
	{
		num1 = num1 * 10 + (number1[i] - '0');
	}
	int num2 = 0;
	for (int i = 0; i < c2; i++)
	{
		num2 = num2 * 10 + (number2[i] - '0');
	}
	int r = num1 / num2;

	int c3 = 0;
	int rr = r;
	while (r > 0)
	{
		r /= 10;
		c3++;
	}
	result = (char*)malloc(c3 * sizeof(char));
	for (int i = c3 -1; i >= 0; i--)
	{
		result[i] = (rr % 10) + '0';
		rr /= 10;
	}
	result[c3] = '\0';

}
int main()
{
	char Str1[50] = "123";

	char str2[50] = "10";

	char res[50];

	strstrX(Str1, str2, res);

	printf_s("%s",res); // HERE A PROBLEM 

	return 0;
}

[seeplus]

result = (char*)malloc(c3 * sizeof(char));

This line isn't needed as result is the array passed in main().

If this line is removed, then it prints 12

The code can also be somewhat simplified. Consider:

#include <stdio.h>
#include <string.h>

void strstrX(const char* number1, const char* number2, char* result)
{
	int num1 = 0, num2 = 0;

	for (; *number1; ++number1)
		num1 = num1 * 10 + (*number1 - '0');

	for (; *number2; ++number2)
		num2 = num2 * 10 + (*number2 - '0');

	int r = num1 / num2;
	int rr = r;
	int c3 = 0;

	for (; r > 0; ++c3)
		r /= 10;

	for (int i = c3 - 1; i >= 0; i--, rr /= 10)
		result[i] = (rr % 10) + '0';

	result[c3] = '\0';
}

int main()
{
	const char Str1[50] = "123";
	const char str2[50] = "10";
	char res[50];

	strstrX(Str1, str2, res);

	printf_s("%s", res);
	return 0;
}

[ne555]

* use meaningful names
* use functions

void integer_division(const char* number1, const char* number2, char* result){
   int num1 = str2int(number1);
   int num2 = str2int(number2);
   int r = num1/num2;
   int2str(r, result);
}

[seeplus]

#include <stdio.h>
#include <stdlib.h>

void strstrX(const char* number1, const char* number2, char result[50])
{
	snprintf(result, 50, "%i", atoi(number1) / atoi(number2));
}

int main()
{
	const char Str1[50] = "123";
	const char str2[50] = "10";
	char res[50];

	strstrX(Str1, str2, res);

	printf_s("%s", res);
	return 0;
}