c - 模块化编程的 C 分段错误

Question

我需要创建一个程序来获取歌曲并将它们作为播放列表输出。这是我第一次使用 malloc 和链表，我遇到了分段错误，我不知道它来自哪里。我认为我没有过度分配任何内存，也不知道如何调试或使用 gdb 来解决这个问题。

song.h 头文件

#ifndef SONG_H
#define SONG_H
struct song {
    char name[50];
    char artist[50];
    int duration;
    char genre[50];
    struct song* next_song;
    int ID_in_playlist;
};

struct song *getValue (int id);
void Song_New (void);
void Song_Print (void);
void print1song (struct song *ptr);
void CleanUp(struct song *list);
void clean(void);


#endif

歌曲.c 文件

#include <stdio.h>
#include <stdlib.h>
#include "song.h"


struct song * firstSong = NULL;
struct song * addedSong = NULL;

struct song *getValue (int id){

    struct song * ptr = NULL;
    ptr = malloc(sizeof(struct song));
    
    if (ptr != NULL){
        ptr->next_song = NULL;
        ptr->ID_in_playlist = id;

        printf("Type in your song name: ");
        scanf("%s", ptr->name);
        
        printf("Type in your artist name: ");
        scanf("%s", ptr->artist);
        
        printf("Type in your song duration (in seconds): ");
        scanf("%d", &ptr->duration);
        
        printf("Type in your song genre: ");
        scanf("%s", ptr->genre); 
    }
    
    else{
        printf("Allocation Failure!\n");
    }
    
    return ptr;
}

void print1song(struct song *ptr){
    if (ptr == NULL)
    {
        printf("The value is NULL\n");
    }

    else{
        printf("Name: %s", ptr -> name);
        printf("  Artist: %s", ptr -> artist);
        printf("  Duration: %i", ptr -> duration);
        printf("  Genre: %s", ptr -> genre);
        printf("ID: %d\n", ptr -> ID_in_playlist);
    }
    

    return;
}

void Song_New(){
    int counter = 1;
    if (firstSong == NULL){
        firstSong = getValue(1);
        if (firstSong != NULL){
            addedSong = firstSong;
        }
    }

    else{
        addedSong->next_song = getValue(counter+1);
        if(addedSong->next_song != NULL){
            addedSong = addedSong->next_song;
        }
    }
    printf("Song added successfully!\n");
    counter = counter + 1;

}

void Song_Print (){

    struct song *t;
    t = firstSong;
    if(t == NULL){
        printf("List is empty\n");
    }
    else{
        while(t){
            print1song(t);
            t = t->next_song;
        }
    }
}

void CleanUp(struct song *list){
    struct song *next;
    while(list)
    {
        next = list->next_song;
        free(list);
        list = next;
    }
}

void clean(void){
    CleanUp(firstSong);
    firstSong = NULL;
    addedSong = NULL;

    return;
}

main.c 文件

#include <stdio.h>
#include <stdlib.h>
#include "song.h"


int main (void){
    int ans;
    while(1){
        printf("Press 1 to add a new song\n");
        printf("Press 2 to print your songs\n");
        printf("Press 3 to quit\n");
        printf("Input: ");
        scanf("%d", ans);

        if (ans == 1){
            Song_New();
        }

        if (ans == 2){
            Song_Print();
        }

        if (ans == 3){
            printf("Exiting program...");
            break;
        }
    }

    clean();
    return 0;
}

标签： cmallocmodular