Thread: Trying to print out Linked List but its prints out incorrectly.

The trouble is that my programme is printing out a load of rubbish when I try and print out the Linked List.

Its printing out a load of characters such as dollar signs and maths symbols. I figure this is because I'm printing out the element out in the wrong format. Can anyone give me a hand figureing out where I am going wrong please?

Code:

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

typedef struct N {
  char      x[1];      
  struct N *next;      
} List;

List *insertlist(char word[1], List * b)        
{
  List *c = calloc(1, sizeof(List));
  strcpy( c->x, word ); 
  c->next = b;
  return c;
}






int main(int argc, char *argv[])
{
    FILE *fp;
    List *z = NULL;
    int c = 0;
    char x;
    char word[1];
    fp = fopen(argv[1], "r");
    while ( (x = fgetc(fp)) != EOF)
    {
          printf("%c", x);
          if(c==0)
          {
                 if(x == ';')
                 {
                      c = 1;
                      z = insertlist(word, z);
                  }
                  else
                  {
                      z = insertlist(word, z);
                      }
                 }
                 else if(c==1)
                 {
                      if(x == 10)
                      {
                          
                           c = 0;
                           }
                  }
                  
                  
                  }
                  fclose(fp); 
                  
               while(z->next != NULL) {
                      printf("%c", z);
                      
                      z = z->next;
                      }

}

Woah, do

Code:

while(z != NULL)

in that last loop there. Because otherwise if z is null it will try to access z->next and then you will segfault.

Thanks for the reply.

Tried that but it's still printing out the same rubbish.

Code:

while(z->next != NULL) {
                      printf("%c", z);

Here z is the pointer to a list node and so can't be printed as a charactor. If you want to print the charactor in the node then use z->X[0]

Also there's no point in creating arrays with a size of one you might as well just create a single char if thats what you want or if you want a full word in each node then create a char * and assign it's memory dynamically.

Thanks for the replies.

Ok I did this:

printf("%c",z->x[0]);

But now its not printing out anything at all.

Ah of course, silly error.

How do I copy the contents of x into the list then?

If I do this, z = insertlist(x, z);

It tells me:

[Warning] passing arg 1 of `insertlist' makes pointer from integer without a cast

The problem is that this insert function...

Code:

List *insertlist(char word[1], List * b)        
{
  List *c = calloc(1, sizeof(List));
  strcpy( c->x, word ); 
  c->next = b;
  return c;
}

takes char word[1]


If I change this to word the I get errors with the strcpy bit. How can I sort this out?

Yep thanks, had all that sorted out before hand.

Now its still priting out a load of characters.

It reads in the file fine because I tested it.