glib 单向链表

原文地址： http://oss.lzu.edu.cn/modules/newbb/viewtopic.php?topic_id=498&forum=13&move=next

参考地址： http://hi.baidu.com/study_together/blog/item/efa7723a86d28ffe3b87ce3c.html

编译：gcc -g -Wall -O0 fuck.c -o fuck `pkg-config --libs --cflags glib-2.0`

1

创建、添加和销毁

下面的代码将初始化一个 GSList，向其添加两个条目，打印出列表的长度，然后释放它：

#include < glib.h >
#include < stdio.h >
int main( int argc, char ** argv) {
GSList * list = NULL;
printf( " The list is now %d items long\n " , g_slist_length(list));
list = g_slist_append(list, " first " );
list = g_slist_append(list, " second " );
printf( " The list is now %d items long\n " , g_slist_length(list));
g_slist_free(list);
return 0 ;
}

***** Output ***** 

The list is now 0 items long 
The list is now 2 items long 

2

添加然后删除数据

可以添加数据；可能还会需要将其删除。这里是一个示例：

#include < glib.h >
#include < stdio.h >
int main( int argc, char ** argv) {
GSList * list = NULL;
list = g_slist_append(list, " second " );
list = g_slist_prepend(list, " first " );
printf( " The list is now %d items long\n " , g_slist_length(list));
list = g_slist_remove(list, " first " );
printf( " The list is now %d items long\n " , g_slist_length(list));
g_slist_free(list);
return 0 ;
}

***** Output ***** 

The list is now 2 items long 

The list is now 1 items long 

3

删除重复的条目 

这里是当在一个列表中有重复的条目时会发生的问题： 

#include < glib.h >
#include < stdio.h >

int main( int argc, char ** argv) {
GSList * list = NULL;
list = g_slist_append(list, " first " );
list = g_slist_append(list, " second " );
list = g_slist_append(list, " second " );
list = g_slist_append(list, " third " );
list = g_slist_append(list, " third " );
printf( " The list is now %d items long\n " , g_slist_length(list));
list = g_slist_remove(list, " second " );
list = g_slist_remove_all(list, " third " );
printf( " The list is now %d items long\n " , g_slist_length(list));
g_slist_free(list);
return 0 ;
}

***** Output ***** 

The list is now 5 items long 
The list is now 2 items long

4

最后一个、第 n 个 和第 n 个数据

在 GSList 中有了一些条目后，可以通过不同的方式提取它们。这里是一些示例，并在 printf 语句中给出了解释。 

#include < glib.h >
#include < stdio.h >

int main( int argc, char ** argv) {
GSList * list = NULL;
list = g_slist_append(list, " first " );
list = g_slist_append(list, " second " );
list = g_slist_append(list, " third " );
printf( " The last item is '%s'\n " , g_slist_last(list) -> data);
printf( " The item at index '1' is '%s'\n " , g_slist_nth(list, 1 ) -> data);
printf( " Now the item at index '1' the easy way: '%s'\n " , g_slist_nth_data(list, 1 ));
printf( " And the 'next' item after first item is '%s'\n " , g_slist_next(list) -> data);
g_slist_free(list);
return 0 ;
}

***** Output ***** 

The last item is 'third' 
The item at index '1' is 'second' 
Now the item at index '1' the easy way: 'second' 
And the 'next' item after first item is 'second' 

5

使用用户定义的类型

到现在为止我们一直在使用字符串；也就是说，我们只是将指向字符的指针放入到 GSList 中。在下面的代码示例中，

将会定义一个 Person 结构体，并将这个结构体的一些实例放入到 GSList 中：

#include < glib.h >
#include < stdio.h >
#include < stdlib.h >

typedef struct {
char * name;
int shoe_size;
} Person;
int main( int argc, char ** argv) {
GSList * list = NULL;
Person * tom = (Person * )malloc( sizeof (Person));
tom -> name = " Tom " ;
tom -> shoe_size = 12 ;
list = g_slist_append(list, tom);
Person * fred = g_new(Person, 1 ); // allocate memory for one Person struct
fred -> name = " Fred " ;
fred -> shoe_size = 11 ;
list = g_slist_append(list, fred);
printf( " Tom's shoe size is '%d'\n " , ((Person * )list -> data) -> shoe_size);
printf( " The last Person's name is '%s'\n " , ((Person * )g_slist_last(list) -> data) -> name);
g_slist_free(list);
free(tom);
g_free(fred);
return 0 ;
}

***** Output ***** 

Tom's shoe size is '12' 
The last Person's name is 'Fred' 

6

组合、反转，等等 

GSList 附带了一些便利的工具，可以连接和反转列表。这里是它们的工作方式： 

#include < glib.h >
#include < stdio.h >

int main( int argc, char ** argv) {
GSList * list1 = NULL;
list1 = g_slist_append(list1, " first " );
list1 = g_slist_append(list1, " second " );
GSList * list2 = NULL;
list2 = g_slist_append(list2, " third " );
list2 = g_slist_append(list2, " fourth " );
GSList * both = g_slist_concat(list1, list2);
printf( " The third item in the concatenated list is '%s'\n " , g_slist_nth_data(both, 2 ));
GSList * reversed = g_slist_reverse(both);
printf( " The first item in the reversed list is '%s'\n " , reversed -> data);
g_slist_free(reversed);
return 0 ;
}

***** Output ***** 

The third item in the concatenated list is 'third' 
The first item in the reversed list is 'fourth' 

7

简单遍历 

这里是遍历 GSList 中所有内容的一个直观方法： 

#include < glib.h >
#include < stdio.h >

int main( int argc, char ** argv) {
GSList * list = NULL, * iterator = NULL;
list = g_slist_append(list, " first " );
list = g_slist_append(list, " second " );
list = g_slist_append(list, " third " );
for (iterator = list; iterator; iterator = iterator -> next) {
printf( " Current item is '%s'\n " , iterator -> data);
}
g_slist_free(list);
return 0 ;
}

***** Output ***** 

Current item is 'first' 
Current item is 'second' 
Current item is 'third' 

迭代器（iterator）

8

使用函数进行高级遍历

  遍历列表的另一种方法是使用 g_slist_foreach，并提供一个将为列表中的每一个条目调用的函数。 

#include < glib.h >
#include < stdio.h >

void print_iterator(gpointer item, gpointer prefix) {
printf( " %s %s\n " , prefix, item);
}
void print_iterator_short(gpointer item) {
printf( " %s\n " , item);
}
int main( int argc, char ** argv) {
GSList * list = g_slist_append(NULL, g_strdup( " first " ));
list = g_slist_append(list, g_strdup( " second " ));
list = g_slist_append(list, g_strdup( " third " ));
printf( " Iterating with a function:\n " );
g_slist_foreach(list, print_iterator, " --> " );
printf( " Iterating with a shorter function:\n " );
g_slist_foreach(list, (GFunc)print_iterator_short, NULL);
printf( " Now freeing each item\n " );
g_slist_foreach(list, (GFunc)g_free, NULL);
g_slist_free(list);
return 0 ;
}

***** Output ***** 

Iterating with a function: 
--> first 
--> second 
--> third 
Iterating with a shorter function: 
first 
second 
third 
Now freeing each item 

9

使用 GCompareFunc 排序

可以通过提供一个知道如何比较列表中条目的函数来对 GSLit 进行排序。下面的示例展示了对字符串列表进行排序的一种方法：

#include < glib.h >
#include < stdio.h >

gint my_comparator(gconstpointer item1, gconstpointer item2) {
return g_ascii_strcasecmp(item1, item2);
}
int main( int argc, char ** argv) {
GSList * list = g_slist_append(NULL, " Chicago " );
list = g_slist_append(list, " Boston " );
list = g_slist_append(list, " Albany " );
list = g_slist_sort(list, (GCompareFunc)my_comparator);
printf( " The first item is now '%s'\n " , list -> data);
printf( " The last item is now '%s'\n " , g_slist_last(list) -> data);
g_slist_free(list);
return 0 ;
}

***** Output ***** 

The first item is now 'Albany' 
The last item is now 'Chicago'

10

查找元素 

有一些方法可以在 GSList 查找元素。已经介绍了如何简单地遍历列表的全部内容，比较每个条目，直到找到了目标条目。

如果已经拥有了要寻找的数据，而只是想要获得它在列表中的位置，那么可以使用 g_slist_find。最后，可以使用 g_slist_find_custom，

它允许您使用一个函数来检查列表中的每一个条目。下面展示了 g_slist_find 和 g_slist_find_custom： 

#include < glib.h >
#include < stdio.h >

gint my_finder(gconstpointer item) {
return g_ascii_strcasecmp(item, " second " );
}
int main( int argc, char ** argv) {
GSList * list = g_slist_append(NULL, " first " );
list = g_slist_append(list, " second " );
list = g_slist_append(list, " third " );
GSList * item = g_slist_find(list, " second " );
printf( " This should be the 'second' item: '%s'\n " , item -> data);
item = g_slist_find_custom(list, NULL, (GCompareFunc)my_finder);
printf( " Again, this should be the 'second' item: '%s'\n " , item -> data);
item = g_slist_find(list, " delta " );
printf( " 'delta' is not in the list, so we get: '%s'\n " , item ? item -> data : " (null) " );
g_slist_free(list);
return 0 ;
}

***** Output ***** 

This should be the 'second' item: 'second' 
Again, this should be the 'second' item: 'second' 
'delta' is not in the list, so we get: '(null)'

11

通过插入进行高级添加

既然已经接触过几次 GCompareFunc，一些更有趣的插入操作会更有意义。使用 g_slist_insert 可以将条目插入到指定的位置，

使用 g_slist_insert_before 可以将条目插入到特定位置之前，使用 g_slist_insert_sorted 可以进行有序插入。这里是样例：  

#include < glib.h >
#include < stdio.h >

int main( int argc, char ** argv) {
GSList * list = g_slist_append(NULL, " Anaheim " ), * iterator = NULL;
list = g_slist_append(list, " Elkton " );
printf( " Before inserting 'Boston', second item is: '%s'\n " , g_slist_nth(list, 1 ) -> data);
g_slist_insert(list, " Boston " , 1 );
printf( " After insertion, second item is: '%s'\n " , g_slist_nth(list, 1 ) -> data);
list = g_slist_insert_before(list, g_slist_nth(list, 2 ), " Chicago " );
printf( " After an insert_before, third item is: '%s'\n " , g_slist_nth(list, 2 ) -> data);
list = g_slist_insert_sorted(list, " Denver " , (GCompareFunc)g_ascii_strcasecmp);
printf( " After inserting 'Denver', here's the final list:\n " );
g_slist_foreach(list, (GFunc)printf, NULL);
g_slist_free(list);
return 0 ;
}

***** Output ***** 

Before inserting 'Boston', second item is: 'Elkton ' 
After insertion, second item is: 'Boston ' 
After an insert_before, third item is: 'Chicago ' 
After inserting 'Denver', here's the final list: 
Anaheim Boston Chicago Denver Elkton 

12

自定义数据结构排序 (根据字符)

#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
typedef struct { 
    char* name; 
    int shoe_size; 
} Person; 

gint my_comparator(gconstpointer item1, gconstpointer item2) { 
    return g_ascii_strcasecmp(((Person*)item1)->name, ((Person*)item2)->name); 
}

int main(int argc, char** argv) { 
    GSList* list = NULL;
 
    Person* tom = (Person*)malloc(sizeof(Person)); 
    tom->name = "Tom"; 
    tom->shoe_size = 12; 
    list = g_slist_append(list, tom); 

    Person* fred = g_new(Person, 1); // allocate memory for one Person struct 
    fred->name = "Fred"; 
    fred->shoe_size = 11; 
    list = g_slist_append(list, fred);

    Person* god = g_new(Person, 1); // allocate memory for one Person struct 
    god->name = "zod";                                                                                                                                                           
    god->shoe_size = 15; 
    list = g_slist_append(list, god);


    list = g_slist_sort(list, (GCompareFunc)my_comparator);

    printf("Tom's shoe size is '%d'\n", ((Person*)list->data)->shoe_size); 
    printf("The last Person's name is '%s'\n", ((Person*)g_slist_last(list)->data)->name); 
    g_slist_free(list); 
    free(tom); 
    g_free(fred);
    g_free(god); 
    return 0; 
}   

   ***** Output *****

Tom's shoe size is '11'

The last Person's name is 'zod'

13 自定义数据结构排序（根据数字）

#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
typedef struct { 
    char* name; 
    int shoe_size; 
} Person; 

gint my_comparator(gconstpointer item1, gconstpointer item2) {
    if(((Person*)item1)->shoe_size > ((Person*)item2)->shoe_size)
    {
        return 1;
    }
    else
    {
        return 0;
    }    
   //  return g_ascii_strcasecmp(((Person*)item1)->name, ((Person*)item2)->name); 
}

int main(int argc, char** argv) { 
    GSList* list = NULL;
 
    Person* tom = (Person*)malloc(sizeof(Person)); 
    tom->name = "Tom"; 
    tom->shoe_size = 10; 
    list = g_slist_append(list, tom); 

    Person* fred = g_new(Person, 1); // allocate memory for one Person struct 
    fred->name = "yred"; 
    fred->shoe_size = 11; 
    list = g_slist_append(list, fred);

    Person* god = g_new(Person, 1); // allocate memory for one Person struct 
    god->name = "zod"; 
    god->shoe_size = 15; 
    list = g_slist_append(list, god);


    list = g_slist_sort(list, (GCompareFunc)my_comparator);

    printf("Tom's shoe size is '%d'\n", ((Person*)list->data)->shoe_size); 
    printf("The last Person's name is '%s'\n", ((Person*)g_slist_last(list)->data)->name); 
    g_slist_free(list); 
    free(tom); 
    g_free(fred);
    g_free(god); 
    return 0; 
} 

*******output*******

Tom's shoe size is '10'
The last Person's name is 'zod'

　　

　　

完