c - 是什么导致了这个段错误？

Question

调用 mygets() 后出现段错误。这是我的代码:

    #include <termios.h>
    #include <stdio.h>
    #include <stdlib.h>
    
    typedef struct _charlist{
        char ch;
        struct _charlist *next;
    }charlist;
    
    static struct termios old, new;
    void mygets(char** p);
    char getche(void); 
    char getch_(int echo);
    void resetTermios(void);
    void initTermios(int echo);
    
    
    int main(void){
        char *p;
        
        printf("\nWho loves orange soda?: ");
        mygets(&p);
        printf("'%s' loves orange soda!", p);
    }
    
    
    void mygets(char** p){
        char c;
        charlist *root, *curr;
        unsigned i, count=0;
    
        root=NULL;
    
    while((c = getche()) != '\n'){      
    
        count++;    
        if(!root){ 
            root = (charlist*) malloc(sizeof(charlist));
            root->ch = c;
                root->next = NULL;
                curr = root;
            }
    
            else{
                curr
->next = (charlist*) malloc(sizeof(charlist));
                curr->next->ch = c;
                curr->next->next = NULL;
                curr = curr->next;
            }
        }
    
        //now request string space.
        *p = (char*) malloc((count+1)*sizeof(char));
    
        printf("\np is now malloced");      //This line doesn't get printed!
        
        //move linked list into string space.
        curr = root;
        for(i=0; i<=count; i++){
            *p[i] = curr->ch;
            curr = curr->next;
        }
    
        //null-terminate the string.
        *p[i] = '\0';
    
    }

有人可以告诉我为什么会出现段错误吗？

除非代码与问题的比率低于某个任意阈值，否则我无法发布此问题。因此，现在有《爱丽丝梦游仙境》第一段，供大家引用。

Alice was beginning to get very tired of sitting by her sister on thebank, and of having nothing to do: once or twice she had peeped intothe book her sister was reading, but it had no pictures orconversations in it, 'and what is the use of a book,' thought Alice'without pictures or conversation?'

Answer 1

何时 func被调用时，会传递局部变量 p 的副本在main 。然后将此副本分配为 malloc编辑区 func 。原文p在 main从未被修改，因此其内容保持未定义，从而在 printf 时导致段错误取消引用p为了打印字符串。

您可能需要func返回 char*指向新分配的区域。