ShallNotBeNamed.c

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

int loopCheck(FILE *file)
{
	int close_counter = 0;
	int open_counter = 0;
	char current_char;

	while ((current_char = fgetc(file)) != EOF)
	{

 		if (current_char == '[')
 			open_counter++;
 		else if (current_char == ']')
 			close_counter++;
	}

	if (open_counter != close_counter)
		return 1;
	return 0;
}

int usableChars(FILE *file)
{
	int characters = 0;
	char current_char;
	while ((current_char = fgetc(file)) != EOF)
	{
 		if (current_char == '+' || current_char == '-' || current_char == '>' || current_char == '<'
 		 || current_char == '[' || current_char == ']' || current_char == '.' || current_char == ',')
 			characters++;
	}
	return characters;
}

int main(int argc, char const *argv[])
{
	// declare varaibles
	FILE *code_file;
	int char_count, command_pointer;
	char current_char;

	if (argv[1] == NULL) // check if ifle exists
	{
		printf("Error: No file specified.\n");
		return 0;
	}
	code_file = fopen(argv[1], "r"); // open file
	if (code_file == NULL) // check if ifle exists
	{
		printf("Error: File not found.\n");
		return 0;
	}

	rewind(code_file); // Check for errors
	if (loopCheck(code_file))
	{
		printf("Error: Mismatched loops.\n");
		return 0;
	}

	rewind(code_file); // set count
	char_count = usableChars(code_file);

	char *text = malloc(char_count + 1); // reserve space for data
	if (text == NULL)
	{
		printf("Error: Memory cannot be allocated.\n");
		return(0);
	}

	// load file
	command_pointer = 0;
	rewind(code_file);
	while ((current_char = fgetc(code_file)) != EOF)
	{
 		if (current_char == '+' || current_char == '-' || current_char == '>' || current_char == '<'
 		 || current_char == '[' || current_char == ']' || current_char == '.' || current_char == ',')
 		{
 			*(text + command_pointer) = current_char;
 			command_pointer++;
 		}
	}
	*(text + command_pointer) = 'x'; // end of program

	fclose(code_file); // close file

	unsigned char bss[256] = {0}; // var date
	unsigned char bss_pointer = 0;
	command_pointer = 0;
	int stack_pointer = 0;
	int stack[1024] = {0};
	// run code
	while (*(text + command_pointer) != 'x')
	{
		switch (*(text + command_pointer))
		{
			case '+' :
				bss[bss_pointer]++;
				command_pointer++;
				break;
			case '-' :
				bss[bss_pointer]--;
				command_pointer++;
				break;
			case '<' :
				bss_pointer--;
				command_pointer++;
				break;
			case '>' :
				bss_pointer++;
				command_pointer++;
				break;
			case '.' :
				printf("%c", bss[bss_pointer]);
				command_pointer++;
				break;
			case ',' :
				bss[bss_pointer] = getchar();
				command_pointer++;
				break;
			case '[' :
				if (stack_pointer == 1024)
				{
					printf("\nError: Stack Overflow.");
					return 0;
				} else {
					stack[stack_pointer] = command_pointer;
					stack_pointer++;
					command_pointer++;
					break;
				}
			case ']' :
				if (bss[bss_pointer] == 0)
				{
					stack[stack_pointer] = 0;
					stack_pointer--;
					command_pointer++;
				} else
					command_pointer = stack[stack_pointer - 1] + 1;
				break;
		}	
	}

	return 0;
}

this is a brainfuck interpreter