Thread: print a text-file in linked list

You're using strcpy wrong. More importantly, you're passing arrays to functions incorrectly. When you pass an array, like when you want to use strcpy, just pass the name of the array. Also, assuming 'liste' is actually a pointer, and not just a structure instance, you're accessing its members incorrectly. To access structure members via pointer, you need the "arrow" operator.

Code:

strcpy( liste->linje, argv[1] );

Of course that's not getting anything from your file. It's just copying your file name (assuming that's what is in argv[1]) into your list.


Quzah.

Ok! Thanks for the help. I've been working a couple of hours more now and figured some things out. A simplified code piece:

Code:

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

#define MAX 2000
#define LENGTH 200

struct song {
  struct song *next;
  char *line;
};

int main(int argc, char *argv[])
       struct song *list = NULL, *last = NULL, *pdp;
	pdp = malloc(sizeof(struct song));
       int n_lines;
       char *ant;

/* Check if file can be opened*/
  	char c[10];
  	FILE *file;
  	file = fopen(argv[2], "r"); 
  	  if(file==NULL) {
    	    printf("Error: Can't open file.\n");
    	    exit(1);
  	  }   
	
/* Copy the text into list */
	while (1) {
	  ant = malloc(LENGTH );
	    if (fgets(ant,LENGTH ,file) == NULL) {
	      free(ant); break;
	    }
	  pdp->next = NULL; pdp->line = malloc(*ant);
	  strcpy(pdp->line, ant);
	    if (list == NULL) {
	       list = last = pdp;
	    } else {
	      last->next = pdp; 
	      last = pdp;
	    }
	}
/* Print the list */
	pdp = liste;
	  while (pdp) {
	    printf("%s\n", pdp->line);
	    pdp = pdp->next;
	  }

I can figure out why the output prints the last line in the text-file infinite times (only stopped by CTRL+C). I think it has something to do with "fgets" but I maybe wrong.

Where are you declaring ant_line?

And pdp->line = malloc(*ant); is wrong. You want malloc(strlen(ant->line) + 1) instead.

Well is ant a pointer to a structure or union?

Originally Posted by tidemann

It should be a pointer to a struct(ure).

If that's what it should be, why did you declare it as pointer-to-char?

One of you malloc calls needs to go - you don't need both.

Option 1 - read into array, then allocate space and copy
char buff[BUFSIZ]; fgets( buff, sizeof buff, file );
pdp->line = malloc(strlen(buff)+1);
strcpy(pdp->line, ant);

Option 2 - allocate space, read in a line then save the pointer
ant = malloc(LENGTH );
fgets(ant,LENGTH,file)
pdp->line = ant;