Working on linked list data structure for hosts.

CMakeLists.txt

@@ -1,3 +1,3 @@
 project(HostBlocker)
 find_package(PkgConfig REQUIRED)
-add_executable(hb main.c)
+add_executable(hb main.c linkedlist.c linkedlist.h)

linkedlist.c

@@ -0,0 +1,37 @@
+//
+// Created by jake on 12/17/19.
+//
+
+#include "linkedlist.h"
+
+LinkedList *linkedlist_new() {
+    LinkedList *tmp = (LinkedList *) malloc(sizeof(LinkedList));
+    tmp->data = NULL;
+    return tmp;
+}
+
+/**
+ * Add a char * to our linked list and set up a new head.
+ * @param head The first node in the list.
+ * @param data Our data to add to the list.
+ * @return
+ */
+void *linkedlist_add(LinkedList *head, char *data) {
+    if (head == NULL) {
+        head = linkedlist_new();
+    }
+    if (head->data == NULL) {
+        head->data = data;
+    }
+    LinkedList *tmp = linkedlist_new();
+    // Set the head pointer to the next node.
+    head->next = tmp;
+
+    // Set head to tmp.
+    head = tmp;
+}
+
+void free_node(LinkedList *node) {
+    free(node->data);
+    free(node);
+}

linkedlist.h

@@ -0,0 +1,21 @@
+//
+// Created by jake on 12/17/19.
+//
+
+#ifndef HOSTBLOCKER_LINKEDLIST_H
+#define HOSTBLOCKER_LINKEDLIST_H
+
+#include <stdlib.h>
+
+/**
+ * Our linked list structure to be used for holding configuration files.
+ */
+typedef struct linkedlist {
+    char *data;
+    struct linkedlist *next;
+} LinkedList;
+
+LinkedList *linkedlist_new();
+void *linkedlist_add(LinkedList *head, char *data);
+
+#endif //HOSTBLOCKER_LINKEDLIST_H

main.c

@@ -6,6 +6,8 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 
+#include "linkedlist.h"
+
 // Macro for status checks.
 #define ONFAILED(status, fn) if(status > fn)
 
@@ -19,7 +21,8 @@
 /** GLOBALS **/
 // Our rule we use to blackhole domains
 const char *blockString = "0.0.0.0 ";
-const char *CONFIG;
+LinkedList *hosts = (LinkedList *) NULL;
+
 // The current hardcoded location of the hosts file.
 static const char *HOSTFILE = "/etc/hosts";
 // Our configuration
@@ -97,7 +100,7 @@ void showHosts()
  */
 int read_config_file() {
     // increment the refcount for tmp.
-
+    linkedlist_add(hosts, "hello.com");
 }
 
 /**