Question

Please help me. I can’t figure out why I get a core dumped when I run this program. Before returning anything I can print all_albums_p just fine. Why am I getting core dumped?

#include "music_server.h"

struct album_ {
  int num_tracks;
  char **tracks;
  int **playlist_hits;

};
typedef struct album_ album;

album *parse_album(FILE *album_file,int *number_of_albums){

  int number_of_album,number_of_tracks,number_of_charaters;
  int i,j;
  char dummy_space;
  int *p;

  fscanf(album_file,"%d", &number_of_album);

  *number_of_albums = number_of_album;

  album *all_albums_p = (album *)malloc(sizeof(album)*number_of_album);

  for(j=0;j<number_of_album;j++){

    fscanf(album_file,"%d", &all_albums_p[j].num_tracks);

    all_albums_p[j].tracks = calloc(all_albums_p[j].num_tracks,sizeof(char));
    all_albums_p[j].playlist_hits = calloc(all_albums_p[j].num_tracks,sizeof(int));

    /*Line 27*/ for(i=0;i<all_albums_p[j].num_tracks;i++){

      fscanf(album_file,"%d", &number_of_charaters);

      all_albums_p[j].tracks[i] = (char *)calloc(number_of_charaters+1,sizeof(char));
      all_albums_p[j].playlist_hits[i] = (int *)malloc(sizeof(int));
      all_albums_p[j].playlist_hits[i] = 0;
      fscanf(album_file," ",dummy_space);
      fscanf(album_file, "%[^\n]s", all_albums_p[j].tracks[i]);
    }
  }
  return all_albums_p;
}

main(int argc, char *argv[]){

  int i,j;
  int *number_of_albums,*number_of_tracks,a;
  a=0;
  number_of_albums = &a;

  album *all_tracks_ptr;

  album_file = fopen(argv[1],"r");
  transaction_file = fopen(argv[2],"r");

  if((album_file == NULL) || (transaction_file == NULL)){
    printf("Either %s or %s could not be open");
  }else{

    all_tracks_ptr = parse_album(album_file,number_of_albums);


    int number_of_tracks[*number_of_albums];
  }
}

errors:

Bus Error (core dumped)

(gdb) bt
#0  0xff277c9c in _smalloc () from /lib/libc.so.1
#1  0xff277d10 in malloc () from /lib/libc.so.1
#2  0xff263830 in calloc () from /lib/libc.so.1
#3  0x00010dd8 in parse_album (album_file=0xff3675bc,
    number_of_albums=0xffbff894) at functions.c:27
#4  0x00010b80 in main (argc=3, argv=0xffbff90c) at project3.c:19

Answer 1

You should allocate sizeof(char*) below instead of sizeof(char)

all_albums_p[j].tracks = alloc(all_albums_p[j].num_tracks,sizeof(char*));