linux中的部分宏

*:first-child {
margin-top: 0 !important;
}

body>*:last-child {
margin-bottom: 0 !important;
}

/* BLOCKS
=============================================================================*/

p, blockquote, ul, ol, dl, table, pre {
margin: 15px 0;
}

/* HEADERS
=============================================================================*/

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
}

h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
font-size: inherit;
}

h1 {
font-size: 28px;
color: #000;
}

h2 {
font-size: 24px;
border-bottom: 1px solid #ccc;
color: #000;
}

h3 {
font-size: 18px;
}

h4 {
font-size: 16px;
}

h5 {
font-size: 14px;
}

h6 {
color: #777;
font-size: 14px;
}

body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
margin-top: 0;
padding-top: 0;
}

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0;
}

h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
margin-top: 10px;
}

/* LINKS
=============================================================================*/

a {
color: #4183C4;
text-decoration: none;
}

a:hover {
text-decoration: underline;
}

/* LISTS
=============================================================================*/

ul, ol {
padding-left: 30px;
}

ul li > :first-child,
ol li > :first-child,
ul li ul:first-of-type,
ol li ol:first-of-type,
ul li ol:first-of-type,
ol li ul:first-of-type {
margin-top: 0px;
}

ul ul, ul ol, ol ol, ol ul {
margin-bottom: 0;
}

dl {
padding: 0;
}

dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px;
}

dl dt:first-child {
padding: 0;
}

dl dt>:first-child {
margin-top: 0px;
}

dl dt>:last-child {
margin-bottom: 0px;
}

dl dd {
margin: 0 0 15px;
padding: 0 15px;
}

dl dd>:first-child {
margin-top: 0px;
}

dl dd>:last-child {
margin-bottom: 0px;
}

/* CODE
=============================================================================*/

pre, code, tt {
font-size: 12px;
font-family: Consolas, "Liberation Mono", Courier, monospace;
}

code, tt {
margin: 0 0px;
padding: 0px 0px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px;
}

pre>code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent;
}

pre {
background-color: #f8f8f8;
border: 1px solid #ccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px;
}

pre code, pre tt {
background-color: transparent;
border: none;
}

kbd {
-moz-border-bottom-colors: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background-color: #DDDDDD;
background-image: linear-gradient(#F1F1F1, #DDDDDD);
background-repeat: repeat-x;
border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
border-image: none;
border-radius: 2px 2px 2px 2px;
border-style: solid;
border-width: 1px;
font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
line-height: 10px;
padding: 1px 4px;
}

/* QUOTES
=============================================================================*/

blockquote {
border-left: 4px solid #DDD;
padding: 0 15px;
color: #777;
}

blockquote>:first-child {
margin-top: 0px;
}

blockquote>:last-child {
margin-bottom: 0px;
}

/* HORIZONTAL RULES
=============================================================================*/

hr {
clear: both;
margin: 15px 0;
height: 0px;
overflow: hidden;
border: none;
background: transparent;
border-bottom: 4px solid #ddd;
padding: 0;
}

/* TABLES
=============================================================================*/

table th {
font-weight: bold;
}

table th, table td {
border: 1px solid #ccc;
padding: 6px 13px;
}

table tr {
border-top: 1px solid #ccc;
background-color: #fff;
}

table tr:nth-child(2n) {
background-color: #f8f8f8;
}

/* IMAGES
=============================================================================*/

img {
max-width: 100%
}
-->

---

链表

struct list_head{
    struct list_head *next,*prev;}

链表声明

#define LIST_HEAD_INIT(name) {&(name),&(name)}
================================================
1.静态初始化
#define LIST_HEAD(name)
    struct list_head name = LIST_HEAD_INIT(name)
=================================================
LIST_HEAD(list_name);
==>
    struct list_head list_name = LIST_HEAD_INIT(name);
==>
    struct list_head list_name = {&(list_name), &(list_name)};
    //相当于给一个结构声明加初始化，让list_name的成员变量
    //【next,prev】 = {&(list_name), &(list_name)}

2.运行时初始化
stattic inline void INIT_LIST_HEAD(struct list_head *list)
{
    list->next = list;
    list->prev = list;
}

链表是否为空

static inline int list_empty(const struct list_head* head)
{
    return head->next == head;
}

链表插入

1.插入head后
static inline void list_add(struct list_head* new, struct list_head* head)
{
    __list_add(new, head, head->next);
}
2.插入head->prev后
static inline void list_add_tail(struct list_head* new, struct list_head* head)
{
    __list_add(new, head->prev, head);
}

删除

static inline void list_replace_init(struct list_head *old, struct list_head *new)
{
    list_replace(old,new);
    INIT_LIST_HEAD(old);
}

遍历

#define list_entry(ptr, type, member) \
    container_of(ptr, type, member)

#define container_of(ptr, type, member) \
{\
    const typeof( ((type *)0)->member ) *__mptr = (ptr);\
    (type *)( (char *)__mptr - offsetof(type,member) ); \
}

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

注意：为什么能这么实现，跟C语言特性很有关系，在C中，给定的结构中，成员的偏移在编译时被固定下来了。

遍历链表：
宏：list_for_each()
#define list_for_each(pos, head) \
for (pos = (head)->next, prefetch(pos->next); \
        pos != (head); \
            pos = pos->next, prefetch(pos->next))

pos是迭代指针，指向当前访问的链表头。
head是要访问的链表的链表头。

结合list_entry使用，就可以访问链表头所在元素了。
list_for_each(p,&elem_list){
    f = list_entry(p, struct elem, list);
}

更简单使用：
宏：list_for_each_entry(pos,head,member)