Error in loop

[Dustin Spencer]

Good afternoon ladies and gentlemen. I would like someone to take a look at my loop to help me find the error that I am making. The purpose of this program is to unscramble the user's input. for example if the user entered 'ftooabll' the program would print 'football'

Now, this only works for strings that are contained in the file wordlist. That being said, I would like this to repeat this search multiple times. Currently, the process is being repeated 7 times, but it only works on the first iteration. The code and sample input/output is below.

Thank you very much for your help.


(p.s. I have only been studying C for about a month, so please bear with me through this.)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NUMLOOP 6
void sort_string(char*);
int main()
{
   char string[100];
   int i, j = 0;
   char string_1[100], string_2[100], string_3[100];
   FILE* wordlist;
   wordlist = fopen("wordlist.txt", "r");
   while (j <= NUMLOOP) {                                                // Start loop to ask for NUMLOOP different strings to search for in the wordlist
      printf("Enter string:\n");                                         // Prompt user for string.
      gets(string);                                                      // Place entered string into "string"
      sort_string(string);                                               // Call to function "sort_string" to alphabetize the characters in "string"
      while (fgets(string_1, sizeof string_1 , wordlist) != NULL)        // Begin loop to search wordlist for match & load wordlist into string_1
      {
         strcpy(string_2, string_1);                                     // Copy string_1 into string_2 to save original format of word
         sort_string(string_1);                                          // alphabetize each string in the wordlist
         int result = strcmp(string, string_1);                          // Compare entered string against the alphabetized wordlist
         if (!result)
         {
            printf("%s", string_2);                                      // If a match is found, print it.
         }
      }
      ++j;
   }
   return 0;
}
void sort_string(char *s)
{
   int c, d = 0, length;
   char *pointer, *result, ch;
 
   length = strlen(s);
 
   result = (char*)malloc(length+1);
 
   pointer = s;
 
   for ( ch = '!' ; ch <= '}' ; ch++ )
   {
      for ( c = 0 ; c < length ; c++ )
      {
         if ( *pointer == ch )
         {
            *(result+d) = *pointer;
            d++;
         }
         pointer++;
      }
      pointer = s;
   }

   *(result+d) = '\0';
 
   strcpy(s, result);
   free(result);
}

Sample input/output:
(note: all data has been verified to be in the wordlist)

Enter string:
4132dcba
abcd1234
Enter string:
4132dcba
Enter string:
4132dcba
Enter string:
4132dcba
Enter string:
4132dcba
Enter string:
4132dcba
Enter string:
4132dcba

[Yarin]

It's time to refactor, buddy. That's a tiny program but it already makes my head hurt trying to parse it.
Refactor it, then I'll look at it, but my guess is that I won't have to, you'll probably discover your mistake yourself while your refactoring it.

Anyway, you don't need to make sort_string() do all the work, C already has qsort().

[Matticus]

The first time you get to the end of your "while()" loop, you're at the end of your file. Look into the "rewind()" function.

---

Some more stuff...

I noticed you use both "fgets()" and "gets()". "gets()" is unsafe and depreciated - I'd strongly recommend just using "fgets()".

FAQ > Why gets() is bad / Buffer Overflows - Cprogramming.com
FAQ > Get a line of text from the user/keyboard (C) - Cprogramming.com

You also don't need to cast malloc:

FAQ > Casting malloc - Cprogramming.com

You should check the return value of "fopen()" before trying to access the file. If it fails to open properly, you don't want to try accessing it.

(p.s. I have only been studying C for about a month, so please bear with me through this.)

Keep up the good work!

[Click_here]

Some tips to help
"gets()" is a very bad function to use.
FAQ > Why gets() is bad / Buffer Overflows - Cprogramming.com

Casting malloc is considered poor programming practice in the C language
FAQ > Casting malloc - Cprogramming.com

In the C language, it's a good idea to put "void" in your main declaration if you do not wish to have any arguments from the command line
FAQ > main() / void main() / int main() / int main(void) / int main(int argc, char *argv[]) - Cprogramming.com



[edit]
You beat me to it!
[/edit]