tac, ls fixes

1 files changed, 32 insertions, 0 deletions

diff --git a/src/util/stack.c b/src/util/stack.c
new file mode 100644
index 0000000..15d5a8e
--- /dev/null
+++ b/src/util/stack.c
@@ -0,0 +1,32 @@
+#include "stack.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void stack_init(struct Stack* stack, size_t size) {
+    stack->size = 0;
+    stack->capacity = size;
+    stack->data = malloc(size);
+}
+
+void stack_push(struct Stack* stack, void* data, size_t len) {
+    size_t new_size = stack->size + len;
+    if (new_size >= stack->capacity) {
+        stack->capacity = new_size * 2;
+        stack->data = realloc(stack->data, stack->capacity);
+    }
+    memcpy((uint8_t*)stack->data + stack->size, data, len);
+    stack->size += len;
+}
+
+void* stack_pop(struct Stack* stack, size_t len) {
+    if (stack->size < len) return NULL;
+    stack->size -= len;
+    return (uint8_t*)stack->data + stack->size;
+}
+
+void stack_free(struct Stack *stack) {
+    free(stack->data);
+}