I'm experiencing a problem with a C program. I am allocating two nodes
dynamically and creating a linked list. The problem is when I return from
the function, it gives me a segmentation fault. My code looks fine, and
it runs fine under digital unix. Do I have to do something different with
linux when using dynamic memory? I've attached my code if someone would
look at it. Thanks for the help.
#include <stdio.h>
#include <stdlib.h>
struct linked_list
{
char name[50];
struct linked_list *next;
};
typedef struct linked_list ELEMENT;
typedef ELEMENT *link;
/* Function prototypes */
link read_file(void);
/*-----------------------------------------------------------*/
int main(void)
{
link h;
printf("\n%s\n", "hello1");
h = read_file();
printf("\n\n%s\n\n", "back");
printf("\%s\n", h->name);
printf("\n%s\n", "hello");
return 0;
}
link read_file(void)
{
char filename; FILE *ifp;
link extraptr = NULL;
link headptr = NULL;
printf("%s", "Enter file name: ");
scanf("%s", &filename);
ifp = fopen(&filename, "r"); /* open file */
if (ifp == NULL) /* check if file exists */
{
printf("\n%s%s%s\n", "Error, the file \"", &filename, "\" does not exist or
cannot be accessed.");
exit(1);
}
else
printf("\n%s%s%s\n\n", "Attempting to open \"", &filename, "\" ...");
headptr = malloc(sizeof(ELEMENT)); /* create head node */
fscanf(ifp, "%s", headptr->name); /* read first name into array */
headptr->next = NULL; /* mark link to next node as null */
extraptr = headptr;
/* while ((extraptr->name) != "") */
{
extraptr->next = malloc(sizeof(ELEMENT));
extraptr = extraptr->next;
fscanf(ifp, "%s", extraptr->name);
extraptr->next = NULL;
}
fclose(ifp); /* close file */
printf("%s", "done reading...");
printf("\n%s\n\n", "hello");
return headptr;
}
