Thread: Can't get fgets to work properly

Hello.
I'm making a small application to make permutations of strings in order to find any anagrams. These permutations are then checked against a dictionary file using fgets. It compiles nicely but when it is run it just crashes.
Here is the entire source code but I suspect only the "checkDict" function is faulty because everything runs just fine when I comment it out.

Code:

#include <stdio.h>
#define VERSION 0.7
#define MAX_DICT_LEN 100
#define MAX_RESULTS 10

int maxResultsCounter = 0;
char *temp;
FILE *dict;

// check current permutation against entire dict.txt
void checkDict(char *str){
	while(fgets(temp, MAX_DICT_LEN, dict) != NULL)
		if(strcmp(str, temp) == 0){
			printf("%s\n", str);
			maxResultsCounter++;
		}
}

// swap *first and *second
void swap(char* first, char* second){
	char temp = *second;
	*second = *first;
	*first = temp;
}

// compute permutations
int perm(char* set, int begin, int end){
	int i, c = 0, range = end - begin;
	if(range == 1){
		
		// MAX_RESULTS invariant
		if(maxResultsCounter > MAX_RESULTS)
			return 0;
		//checkDict(set);
	}
	else
		for(i = 0; i < range; i++){
			swap(&set[begin], &set[begin+i]);	// first swap
			perm(set, begin+1, end);			// recursion
			swap(&set[begin], &set[begin+i]);	// swap back
		}
	return 0;
}

int main(int argc, char *argv[]){
	
	// test arguments
	if(argc == 1 || argc > 3){
		printf("AnagramAnalyzer (v. %2.1f)\n\n", VERSION);
		printf("syntax: \n\t* <anagram> <args>\n\n");
		printf("args: \n\t[-s] adds a space to the anagram\n");
		return 0;
	}		
	
	char *in = argv[1];
	
	// convert to lower case
	int i, len = strlen(in);
	for(i = 0; i < len; i++)
		if(in[i] > 64 && in[i] < 91)
			in[i] += 32;
		
	// check for additional arguments
	if(argc == 3 && strcmp(argv[2], "-s") == 0){
		in[len] = ' ';
		in[len+1] = '\0';
		len++;
	}
	
	// open file stream
	if((dict = fopen("dict.txt", "r")) == NULL){
		printf("Couldn't locate dict file!\n");
		return 0;
	}
	
	// permutate and check dictionary
	printf("Checking...\n");
	perm(in, 0, len);
	
	// stop and close
	fclose(dict);
	return 0;
}