Question

Trying to take in several file names from the user at the command line and store them into a linked list, but I’m receiving a segmentation fault. The idea is to have the user enter each file name then enter ‘q’ when they’re finished.

I enter in the first file name, “man_on_moon.txt” and no error occurs. After I enter the second, “sat_moons_rings.txt” I get.. Segmentation fault: 11
I believe it’s occurring in my assignment to char *name, but am not sure.

char *name = malloc(sizeof(char) *50);
scanf("%s", name);
list *curr, *head;
curr = malloc(sizeof(list));
head = malloc(sizeof(head));
if(name != "q")
{
    curr->item = name;
    head->next = curr;
    curr = curr->next;
    scanf("%s", name);
}
while(name != "q")
{
    curr->item = name;
    curr = curr->next;
    scanf("%s", name);
}

Answer 1

You never set curr->next to anything so it’s pointing to NULL then you set curr to curr->next. Therefore when you get into the while loop you access curr->item you are trying to get the fields of NULL and you get a segfault.

The reason behind this is you are only mallocing space for 2 nodes. You have malloc space for every node you make.