C++ STL Stack file loading test

cpp_stack_test.cpp

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <stack>
#include "benchmark/benchmark.h"

void test_func(void *data, size_t numBytes)
{
	std::stack<char> myStack;
	char *testData = (char *) data, *p;
	FILE *fp;

	for(p = testData; p < testData + numBytes; ++p)
	{
		try
		{
			myStack.push(*p);
		}
		catch(...)
		{
			printf("ERROR! %lu\n", p - testData);
			exit(5);
		}
	}

	if((fp = fopen("test.txt", "w")) == NULL)
	{
		printf("Error, couldn't open file!");
		exit(6);
	}

	while(!myStack.empty())
	{
		try
		{
			fputc(myStack.top(), fp);
			myStack.pop();
		}
		catch(...)
		{
			printf("ERROR! Couldn't pop item number %lu\n", myStack.size());
			exit(7);
		}
	}

	fclose(fp);
}

int main(int argc, char **argv)
{
	FILE *fp;
	long byteCount, numSteps;
	void *fileText;

	if(argc != 4)
	{
		printf("Error! Expected 4 arguments!\n");
		return 5;
	}

	if((fp = fopen(argv[1], "r")) == NULL)
	{
		printf("Problem with argv[1].\n");
		return 1;
	}

	if((byteCount = strtol(argv[2], NULL, 10)) == 0L)
	{
		printf("Problem with argv[2].\n");
		return 2;
	}

	if((numSteps = strtol(argv[3], NULL, 10)) == 0L)
	{
		printf("Problem with argv[3].\n");
		return 3;
	}

	fileText = malloc(byteCount);

	if(fread(fileText, 1, byteCount, fp) != (size_t) byteCount)
	{
		printf("Couldn't read file properly.\n");
		return 4;
	}

	benchmark(test_func, fileText, byteCount, numSteps);

	fclose(fp);
	free(fileText);

	return 0;
}