1 files changed, 100 insertions, 0 deletions
diff --git a/beef.c b/beef.c
new file mode 100644
index 0000000..1e7940e
--- /dev/null
+++ b/beef.c
@@ -0,0 +1,100 @@
+#include <stdlib.h>
+#include <stdio.h>
+#define SIZE 1024
+
+struct stack {
+	long int data;
+	struct stack *next;
+};
+
+void push(struct stack **s, long int i) {
+	struct stack *nuevo = malloc(sizeof(struct stack));
+	nuevo->data = i;
+	nuevo->next = *s;
+	*s = nuevo;
+}
+
+void pop(struct stack **s) {
+	struct stack *temp = *s;
+	*s = (*s)->next;
+	free(temp);
+}
+
+int main(int argc, char **argv) {
+	if (argc != 2) return 1;
+	FILE *source = fopen(argv[1], "r");
+	if (!source) return 1;
+	struct stack *open_brackets = 0;
+	char tape[SIZE] = {0};
+	char *curr = tape;
+	int lineNr = 1;
+	int exit = 0;
+	while (!feof(source) && !exit) {
+		char c = fgetc(source);
+		switch (c) {
+		case '\n':
+			lineNr++;
+			break;
+		case '+':
+			*curr += 1;
+			break;
+		case '-':
+			*curr -= 1;
+			break;
+		case '>':
+			if (curr != &tape[SIZE - 1]) curr++;
+			else curr = &tape[0];
+			break;
+		case '<':
+			if (curr != &tape[0]) curr--;
+			else curr = &tape[SIZE - 1];
+			break;
+		case '.':
+			putchar(*curr);
+			break;
+		case ',':
+			*curr = getchar();
+			break;
+		case '[':
+			if (*curr) {
+				push(&open_brackets, ftell(source));
+			}
+			else {
+				int counter = 1;
+				while (counter > 0 && !feof(source)) {
+					c = fgetc(source);
+					if (c == '[') counter++;
+					else if (c == ']') counter--;
+				}
+				if (feof(source)) {
+					printf("Error: Can't find matching ']' at line %d\n", lineNr);
+					exit = 1;
+				}
+			}
+			break;
+		case ']':
+			if (*curr && open_brackets) {
+				fseek(source, open_brackets->data, SEEK_SET);
+			}
+			else if (open_brackets){
+				pop(&open_brackets);
+			}
+			else {
+				printf("Error: Can't find matching '[' at line %d\n", lineNr);
+				exit = 1;
+			}
+		}
+	}
+	if (open_brackets) {
+		lineNr = 1;
+		rewind(source);
+		while (ftell(source) != open_brackets->data) {
+			if (fgetc(source) == '\n') lineNr++;
+		}
+		printf("Error: Can't find matching ']' at line %d\n", lineNr);
+		while (open_brackets) pop(&open_brackets);
+		exit = 1;
+	}
+	fclose(source);
+	return exit;
+}