虽然您已经为 SegFault 找到了答案，但您还可以在其他领域清理和重构代码，以便更高效地协同工作。由于您使用列表结构liste 来保存指向first 中列表开头的指针，因此您还可以添加另一个指针last 以指向列表中的最后一个节点，从而不必迭代到每次插入的最后一个节点。使用last（或tail）指针，您的新节点始终插入last->next。例如，您的 Liste 结构可能是：
typedef struct Liste Liste;
struct Liste {
Element *first, *last;
};
您的列表函数每个应该做一件事，这意味着initialize() 应该只分配和初始化Liste 节点及其指针。 read() 应该分配和读取并返回一个指向已填充节点的有效指针，或者在失败时返回 NULL。 insert() 应该这样做，将Liste 列表地址m 和来自read() 的节点插入到列表中。把这些功能放在一起你可以做：
Element *read()
{
Element *element = malloc (sizeof(*element)); /* allocate */
if (element == NULL) /* validate */
return NULL;
element->next = NULL; /* initialize */
printf ("\nPlease provide first name : ");
if (scanf ("%9s", element->f_name) != 1) /* validate EVERY input */
goto badread;
printf ("Please provide last name : ");
if (scanf ("%9s", element->l_name) != 1)
goto badread;
printf ("Please provide score : ");
if (scanf ("%f", &element->score) != 1)
goto badread;
return element; /* return allocated and initialized element */
badread:; /* just a simple goto label for handling read error */
free (element); /* free memory of node if error */
return NULL;
}
（注意：使用goto 将您发送到超出正常返回的标签，您可以在其中为填充期间失败的节点释放内存。）
/* initialize the list, don't worry about the elements */
Liste *initialize (void)
{
Liste *liste = malloc(sizeof *liste);
if (liste == NULL) {
perror ("malloc-liste"); /* give some meaningful error */
exit (EXIT_FAILURE);
}
liste->first = liste->last = NULL;
return liste;
}
void insert (Liste *liste, Element *nouveau)
{
if (liste == NULL || nouveau == NULL)
exit (EXIT_FAILURE);
if (!liste->first) /* inserting 1st node */
liste->first = liste->last = nouveau;
else { /* inserting all others */
liste->last->next = nouveau;
liste->last = nouveau;
}
}
（注意：初始化和插入是直截了当的，你处理的唯一两个类是插入第一个节点还是所有其他节点。让它非常简单）
总而言之，您可以编写完整的测试代码，如下所示添加一个函数来迭代列表打印值，然后使用一个类似的函数来迭代列表释放节点，最后是列表：：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXN 10 /* if you need a constant, #define one (or more) */
typedef struct Element Element;
struct Element {
char f_name[MAXN];
char l_name[MAXN];
float score;
Element* next;
};
typedef struct Liste Liste;
struct Liste {
Element *first, *last;
};
Element *read()
{
Element *element = malloc (sizeof(*element)); /* allocate */
if (element == NULL) /* validate */
return NULL;
element->next = NULL; /* initialize */
printf ("\nPlease provide first name : ");
if (scanf ("%9s", element->f_name) != 1) /* validate EVERY input */
goto badread;
printf ("Please provide last name : ");
if (scanf ("%9s", element->l_name) != 1)
goto badread;
printf ("Please provide score : ");
if (scanf ("%f", &element->score) != 1)
goto badread;
return element; /* return allocated and initialized element */
badread:; /* just a simple goto label for handling read error */
free (element); /* free memory of node if error */
return NULL;
}
/* initialize the list, don't worry about the elements */
Liste *initialize (void)
{
Liste *liste = malloc(sizeof *liste);
if (liste == NULL) {
perror ("malloc-liste"); /* give some meaningful error */
exit (EXIT_FAILURE);
}
liste->first = liste->last = NULL;
return liste;
}
void insert (Liste *liste, Element *nouveau)
{
if (liste == NULL || nouveau == NULL)
exit (EXIT_FAILURE);
if (!liste->first) /* inserting 1st node */
liste->first = liste->last = nouveau;
else { /* inserting all others */
liste->last->next = nouveau;
liste->last = nouveau;
}
}
void prnlist (Liste *liste)
{
Element *iter = liste->first;
while (iter) { /* just iterate list outputting values */
printf ("%-10s %-10s -> %.2f\n",
iter->f_name, iter->l_name, iter->score);
iter = iter->next;
}
}
void freelist (Liste *liste)
{
Element *iter = liste->first;
while (iter) {
Element *victim = iter;
iter = iter->next; /* iterate to next node BEFORE */
free (victim); /* you free victim */
}
free (liste);
}
int main (void) {
Liste *maListe = initialize(); /* create/initialize list */
Element *node;
while ((node = read())) /* allocate/read */
insert (maListe, node); /* insert */
puts ("\n\nElements in list:\n"); /* output list values */
prnlist (maListe);
freelist (maListe); /* don't forget to free what you allocate */
return 0;
}
使用/输出示例
$ ./bin/ll_liste
Please provide first name : Donald
Please provide last name : Duck
Please provide score : 99.2
Please provide first name : Minnie
Please provide last name : Mouse
Please provide score : 99.7
Please provide first name : Pluto
Please provide last name : Dog
Please provide score : 83.5
Please provide first name :
Elements in list:
Donald Duck -> 99.20
Minnie Mouse -> 99.70
Pluto Dog -> 83.50
内存使用/错误检查
在您编写的任何动态分配内存的代码中，对于分配的任何内存块，您都有 2 个职责：(1)始终保留指向起始地址的指针内存块，因此 (2) 当不再需要它时可以释放。
您必须使用内存错误检查程序来确保您不会尝试访问内存或写入超出/超出分配块的边界，尝试读取或基于未初始化的值进行条件跳转，最后，以确认您释放了已分配的所有内存。
对于 Linux，valgrind 是正常的选择。每个平台都有类似的内存检查器。它们都易于使用，只需通过它运行您的程序即可。
$ valgrind ./bin/ll_liste
==10838== Memcheck, a memory error detector
==10838== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==10838== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==10838== Command: ./bin/ll_liste
==10838==
Please provide first name : Donald
Please provide last name : Duck
Please provide score : 99.2
Please provide first name : Minnie
Please provide last name : Mouse
Please provide score : 99.6
Please provide first name : Pluto
Please provide last name : Dog
Please provide score : 87.2
Please provide first name :
Elements in list:
Donald Duck -> 99.20
Minnie Mouse -> 99.60
Pluto Dog -> 87.20
==10838==
==10838== HEAP SUMMARY:
==10838== in use at exit: 0 bytes in 0 blocks
==10838== total heap usage: 5 allocs, 5 frees, 144 bytes allocated
==10838==
==10838== All heap blocks were freed -- no leaks are possible
==10838==
==10838== For counts of detected and suppressed errors, rerun with: -v
==10838== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
始终确认您已释放已分配的所有内存并且没有内存错误。
检查一下，如果您有任何问题，请告诉我。