Add tailq example

test/tailq_example.c

@@ -0,0 +1,89 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ucore/tailq.h>
+#include <ucore/utils.h>
+
+struct Block {
+    char text[64];
+    struct TailQ blocks;
+};
+
+struct File {
+   char name[128];
+   struct TailQ head;
+};
+
+void add_block(struct File *f, const char *txt)
+{
+   struct Block *b = malloc(sizeof *b);
+   strcpy(b->text,txt); 
+   uc_tailq_insert_tail(&f->head, &b->blocks);
+}
+
+void print_file(struct File *f)
+{
+    struct TailQ *entry;
+    printf("File: %s\n", f->name);
+    UC_TAILQ_FOREACH(entry, &f->head) {
+        struct Block *b = UC_CONTAINER_OF(entry, struct Block, blocks);
+        printf("Block: %s\n", b->text);
+    }
+}
+
+void delete_block(struct File *f, const char *txt)
+{
+    struct TailQ *entry, *next;
+    UC_TAILQ_FOREACH_SAFE(entry, next, &f->head) {
+        struct Block *b = UC_CONTAINER_OF(entry, struct Block, blocks);
+        if (strcmp(txt, b->text) == 0) {
+            uc_tailq_remove(entry);
+            free(b);
+        }
+    }
+}
+
+void delete_all_blocks(struct File *f)
+{
+    struct TailQ *entry, *next;
+    UC_TAILQ_FOREACH_SAFE(entry, next, &f->head) {
+        struct Block *b = UC_CONTAINER_OF(entry, struct Block, blocks);
+        free(b);
+    }
+    uc_tailq_init(&f->head);
+}
+
+int main(void)
+{
+    struct File f;
+    uc_tailq_init(&f.head);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+    strcpy(f.name,"Test.f");
+    add_block(&f,"one");
+    add_block(&f,"two");
+    add_block(&f,"three");
+
+    print_file(&f);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+
+    puts("\nDeleting three");
+    delete_block(&f, "three");
+    print_file(&f);
+
+    puts("\nAdding 2 blocks");
+    add_block(&f,"three");
+    add_block(&f,"three");
+    print_file(&f);
+
+    puts("\nDeleting three");
+    delete_block(&f, "three");
+    print_file(&f);
+
+    delete_all_blocks(&f);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+
+
+    return 0;
+}
+
+