Thread: time function for linked list

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>

#define LEN 50
typedef struct L { char k[LEN]; struct L *next; } List;

List *insertList (char head[LEN], List *tail)
{
  List *m = (List*) malloc (sizeof(List));
  strcpy(m -> k,head);
  m -> next = tail;
  return m;
}

void printList (List *v)
{
	while ( v != NULL){
	printf ("%s\n", v -> k);
	v = v -> next;
    }
}

static FILE *open_file ( char *file, char *mode )
{
  FILE *fp = fopen ( file, mode );

  if ( fp == NULL ) {
    perror ( "Unable to open file" );
    exit ( EXIT_FAILURE );
  }

  return fp;
}


int main (int argc, char *argv[])
{	
	int x;
	int wordcount;
	char a;
	char word[LEN];
	List *t = NULL;
	time_t start,end;
	double dif;
	FILE *fp;
	time (&start);
	fp = open_file ( argv[1], "r" );
	wordcount = 0;
    do{
	x = 0;
	do{
	a = fgetc (fp);
	if (a != ' ' && a != '\n' && 
		a != EOF && a !=',' && 
		a !=';' && a !='.'&& 
		a !='!' && a !='?' && 
		a !=':' && a !='`'){
	word[x] = tolower(a);
	  x++;
	  }else{
	if (x != 0){
		word[x] = '\0';
	    t = insertList (word, t);
		wordcount++;
		}
	}
      }while (a != ' ' && a != '\n' && 
			  a != EOF && a !=',' && 
			  a !=';' && a !='.'&& 
			  a !='!' && a !='?' && 
			  a !=':' && a !='`');      
    } while (a != EOF);
	fclose (fp);
	time (&end);
	dif = difftime (end,start);
	printList (t);
	printf ("Total words read: %d\n", wordcount);
	printf ("It took %.2lf seconds to read in words.\n", dif );

	return 0;
}

time always returns 0.00 seconds. Where am i going wrong? thanks

yeah i was thinking the same thing about processors being too fast. guess i will have to look for other funcs other than difftime.cheers anyway

The clock isn't necessarily ticking during I/O operations anyway. If something is running slowly, use a profiler.

matsp, the code u suggested worked with my program. now the obvious question is whether there is a way of converting those ticks into seconds?

btw since time funcs results are platform dependent then i should mention that i am using mac os x 10.5 with xcode on it.

Originally Posted by agentsmith

time funcs results are platform dependent

This isn't true. clock() and time() are standard C functions. In fact, all the time functions described here are part of standard C functions.

Originally Posted by agentsmith

is whether there is a way of converting those ticks into seconds?

I'll modify matsp code to show you how.

Code:

#include <time.h> 
#include <stdio.h> 

int main() 
{
    clock_t t;
    t = clock();
    printf("Press enter...\n");
    getchar();
    t = clock() - t;
    printf("You took %f seconds to press enter\n", (double) t / CLOCKS_PER_SEC);
    return 0;
}

CLOCKS_PER_SEC is a macro defined in time.h.

it all works now. time is returned in seconds just as i wanted. thanks a lot