在我的计划中，我有一个＆＃34;堆栈＆＃34; struct，看起来像这样（在stack.h中）：
struct stack_t {
/* Stack-Datentyp */
/* Stacks have a head-node, a length, and a name.
Stacks are filled with links (nodes) that are defined below. These links have
a generic data pointer and a pointer to the next link */
link head;
unsigned int length;
char *name; //stack name
};
typedef struct stack_t *stack;
在我的main.c中，我调用了一个名为＆＃34; stack_new＆＃34;的函数。这似乎工作正常，因为所有printf调用工作：
stack stack_new(char *stackname) {
/* creates a new, empty stack */
stack st = (stack)(malloc(sizeof(stack)));
if (st == NULL) {
fprintf(stderr, "Error: Memory for Stack could not be allocated!\n");
return NULL;
}
st->head = NULL;
printf("head works.\n");
st->length = 0;
printf("length works.\n");
st->name = stackname;
printf("stackname works.\n");
return st;
}
现在，当我在main.c中调用此函数时，我得到一个seg错误。这是电话：
if (strcmp(input,"newstack") == 0) {
printf("Please enter stackname:\n");
scanf("%s", &stackname);
printf("Debug: Input works.\n");
stacklist[NumberOfStacks] = stack_new(stackname);
printf("stack created works-\n");
NumberOfStacks++;
printf("A new stack with the name '%s' was created!\nIt is number %d in stack list.", stacklist[NumberOfStacks]->name, NumberOfStacks);
continue;
}
当我尝试打印struct stacklist [NumberOfStacks]指向的成员名称时发生seg错误。我在这里做错了什么？
我还收到一堆警告，告诉我有关stackname的scanf如何预期不同的类型：
警告：格式'％s'需要类型为'char '的参数，但参数2的类型为'char（）[50]'[ - Wformat =] scanf（＆＃34;％s＆＃34;，＆amp; stackname）;
其他警告我告诉我，我不是使用我用于堆栈节点中数据存储的void指针进行类型转换，但我不认为这与我的问题相关。
感谢您的帮助！
编辑： 问题是我在使用它作为索引来增加NumberOfStacks，以便打印保存在数组中的结构的成员。
NumberOfStacks++;
printf("A new stack with the name '%s' was created!\nIt is number %d in stack list.", stacklist[NumberOfStacks]->name, NumberOfStacks);
这部分程序现在运行正常，谢谢！
答案 0 :(得分：1)
您的代码中存在一些错误。大多数已在评论中得到解决。我做了更正，似乎没有段错误。 修改由代码中的注释表示。
这是我最终得到的代码：
#include <stdio.h>
// Prototype for malloc
#include <stdlib.h>
// Prototype for strdup
#include <string.h>
typedef void *link; /* Added to make it compile - you may have a different definition in your code */
struct stack_t {
/* Stack-Datentyp */
/* Stacks have a head-node, a length, and a name.
* Stacks are filled with links (nodes) that are defined below.
* These links have
* a generic data pointer and a pointer to the next link */
link head;
unsigned int length;
char *name; //stack name
};
typedef struct stack_t *stack;
stack stack_new(char *stackname) {
/* creates a new, empty stack */
stack st = malloc(sizeof(*st)); // changed to use the variable name
if (st == NULL) {
fprintf(stderr, "Error: Memory for Stack could not be allocated!\n");
return NULL;
}
st->head = NULL;
printf("head works.\n");
st->length = 0;
printf("length works.\n");
st->name = strdup(stackname); // Changed: Duplicate the name so it won't get overwritten when creating the next stack
printf("stackname works.\n");
return st;
}
int main(void)
{
char stackname[50]; // Added declaration for stackname.
stack stacklist[50]; // Added declaration. Can handle up to 50 stacks.
int NumberOfStacks = 0;
printf("Please enter stackname:\n");
scanf("%s", stackname); // Changed. Removed the "&" since stackname is a char*.
printf("Debug: Input works.\n");
stacklist[NumberOfStacks] = stack_new(stackname);
printf("stack created works-\n");
// All data is at index 0, so cannot use increased value of NumberOfStacks to get get the data. Also changed the text to "has index" since a 0 will be printed for stacknumber.
printf("A new stack with the name '%s' was created!\nIt has index %d in stack list.\n", stacklist[NumberOfStacks]->name, NumberOfStacks);
NumberOfStacks++; // Moved this line down.
return 0;
}
答案 1 :(得分：0)
对于警告，scanf正在等待类型'指向char的指针'。你的变量'stackname'被声明为'char stackname [50]'（我想你还没有发布声明）。 使用＆amp; stackname表示您想要访问数组的地址。 stackname或＆amp; stackname的使用几乎相同，因为在第一种情况下，数组将转换为指向数组第一种情况的指针，在第二种情况下，它将是第一种情况下的数组地址数组的情况。
如果要复制字符串，则必须分配字符串大小的缓冲区（使用malloc）并使用strcpy。
对于segfault，请向我们展示stacklist和NumberOfStacks的声明。原因可能是NumberOfStacks的值大于数组的大小。