Segmentation fault while reading binary file in C -

im beginner in c. write , read binary file, , reached far:

i can struct binary file, , can read.

problem one: can read integers, somehow strings printed garbage or random characters.

problem two: if run program, add entries binary file, print entries working fine (except problem one), after terminate program , run again got segmentation fault while try read file.

please me, cannot move forward.

/* our structure */ struct rec {     int max,cost;     char *name; };   struct rec addnewentry() {      //init     char name[256];     int max;     int cost;      //input     printf("type name: \n");     scanf("%s" , &name) ;      printf("type guests limit: \n");     scanf("%d", &max);      printf("type price: \n");     scanf("%d", &cost);      //create record     struct rec record;      record.name = name;     record.max = max;     record.cost = cost;      return record;  }  int main() {      file *ptr_myfile;       //////////////////////////menu////////////////////////////////      int option=-1;       while(option!=3)     {          printf("\n=== menu === \n");         printf("\n1. print entries");         printf("\n2. add new entry");         printf("\n3. exit");         printf("\n");          printf("\ntype menu option:");          scanf("%d", &option);           if(option == 1)         {             printf("\n...printing entries\n");                int f=open("stadionok.db",o_rdonly);              if (f<0){ perror("error @ opening file\n");exit(1);}               struct rec my_record;                while (read(f,&my_record,sizeof(my_record))){ //use write writing                 printf("name: %s  \n",my_record.name);                 printf("max: %d  \n",my_record.max);                 printf("cost: %d  \n",my_record.cost);              }                close(f);           }         else if(option ==2)         {              printf("\n...type new entry\n");               //open , check             ptr_myfile=fopen("stadionok.db","a");             if (!ptr_myfile)             {                 printf("unable open file!");                 return 1;             }              //type new entry             struct rec new_stad = addnewentry();              //write file             fwrite(&new_stad, sizeof(struct rec), 1, ptr_myfile);               //close             fclose(ptr_myfile);              printf("done.\n");         }       }            return 0; } 

e d t:

i modified suggested , got: error: incompatible types in assignment

at:

char name[256];   //input printf("type name: \n"); scanf("%s" , &name) ;   struct rec record;  record.name = name; //here 

the reason garbage strings writing char pointer file. simple way want use char array fixed length inside struct. so:

struct rec {     int max,cost;     char name[1024]; }; 

it reason crash. when read data , trying print string printf() tries read memory block not valid, because memory addresses changed.

if want write strings dynamic size file gets bit more complicated.
should not write struct itself, values of , size of string.
pseudocode example:

write(max); write(cost); write(strlen(name)); // strlen + 1 if want include \0 write(name);  max = readint(); cost = readint(); namelen = readint(); allocatememory(namelen); name = read_n_bytes(namelen); 

edit: if rec.name still pointer (char*) have assign pointer it, not array.

rec.name = &name; 

if rec.name array fixed size now:

strncpy(rec.name, name, sizeof(rec.name)); // copy string rec.name rec.name[strlen(name)] = '\0'; // add binary 0 end of string 

note: if reading more 1 struct (in loop), should not use char name[256];, because every rec.name pointing name overwritten everytime read new value. use following construct every entry:

char* name; //define name pointer name = malloc(256); // allocate new memory block , assign pointer name scanf("%s" , name); // no & needed because name pointer rec.name = name; // no & needed because name pointer