TAILQ Example

最新推荐文章于 2024-01-12 23:18:59 发布

转载最新推荐文章于 2024-01-12 23:18:59 发布 · 61 阅读

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原文链接：https://yq.aliyun.com/articles/227426

本文介绍如何利用sys/queue.h中的TAILQ来创建和操作双向链表。通过具体的代码实例展示了链表的基本操作，包括插入、遍历、删除等，并提供了完整的代码示例。

I plan to use this blog to post codebits that I find myself sending to people over and over again. The first example is how to use a TAILQ from sys/queue.h found on the BSDs. Many Linux distributions also have sys/queue.h but may be missing certain macros such as TAILQ_FOREACH(). At the very least I hope this enticies some newer C programmer to use queue.h rather than rolling their own linked list. I’ll jump directly to the code as I feel it is more or less self explanatory.

The following code can be downloaded here.
















 tailq_entry {
 value;




TAILQ_ENTRY(tailq_entry) entries;
};




TAILQ_HEAD(, tailq_entry) my_tailq_head;

main( argc,  **argv)
{

 tailq_entry *item;

 tailq_entry *tmp_item;
 i;

TAILQ_INIT(&my_tailq_head);

 (i = ; i < ; i++) {




item = malloc((*item));
 (item == ) {
perror();
exit();
}

item->value = i;








TAILQ_INSERT_TAIL(&my_tailq_head, item, entries);
}

printf();
TAILQ_FOREACH(item, &my_tailq_head, entries) {
printf(, item->value);
}
printf();

printf();
TAILQ_FOREACH(item, &my_tailq_head, entries) {
 (item->value == ) {
 tailq_entry *new_item =
malloc((*new_item));
 (new_item == ) {
perror();
exit();
}
new_item->value = ;
TAILQ_INSERT_AFTER(&my_tailq_head, item, new_item,
entries);
;
}
}

TAILQ_FOREACH(item, &my_tailq_head, entries) {
printf(, item->value);
}
printf();








printf();
 (item = TAILQ_FIRST(&my_tailq_head); item != ; item = tmp_item)
{
tmp_item = TAILQ_NEXT(item, entries);
 (item->value == ) {

TAILQ_REMOVE(&my_tailq_head, item, entries);

free(item);
;
}
}

TAILQ_FOREACH(item, &my_tailq_head, entries) {
printf(, item->value);
}
printf();

 (item = TAILQ_FIRST(&my_tailq_head)) {
TAILQ_REMOVE(&my_tailq_head, item, entries);
free(item);
}

 (!TAILQ_EMPTY(&my_tailq_head))
printf();
 ;
}