Lab9: bitwise example

lab9/bitwise.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>  // This gives us sized types
+#include <stdbool.h>
+
+#define NB_NODES 4
+
+bool add_file(uint8_t* inodes, int file_size) {
+    // We only have 7 bits for the file size, so it can't be bigger
+    if (file_size > 0x7f || file_size < 0) {
+        return false;
+    }
+
+    for (int i = 0; i < NB_NODES; i++) {
+        bool is_taken = (inodes[i] & 0x8) > 0;
+
+        if (!is_taken) {
+            uint8_t size = file_size;
+            inodes[i] = size | 0x80;  // Set highest bit + size
+            return true;
+        }
+    }
+
+    return false;
+}
+
+void printd_inodes(uint8_t* inodes) {
+    printf("Debug: ");
+
+    for (int i = 0; i < NB_NODES; i++) {
+        printf("%x", inodes[i]);
+
+        if (i == NB_NODES - 1) {
+            printf("\n");
+        } else {
+            printf(" ");
+        }
+    }
+}
+
+int main(void) {
+    uint8_t* inodes = calloc(NB_NODES, sizeof(uint8_t));
+
+    printd_inodes(inodes);
+
+    add_file(inodes, 8);
+    printd_inodes(inodes);
+
+    add_file(inodes, 12);
+    printd_inodes(inodes);
+
+    add_file(inodes, 121);
+    printd_inodes(inodes);
+
+    add_file(inodes, 127);
+    printd_inodes(inodes);
+
+    FILE* f = fopen("bits.out", "wb");
+
+    char debug_msg[] = "Debug: ";
+    fwrite(debug_msg, sizeof(char), sizeof(debug_msg), f);
+
+    fwrite(inodes, sizeof(uint8_t), NB_NODES, f);
+    fclose(f);
+
+    free(inodes);
+}