Thread: Seg Fault -- Plz Help Quick

i get a stupid seg fault when i try to open/read a file. all works well if the file == NULL and an error has to be printed, but it either just continuly loops or seg faults if the file is a good one. it usually stops on or around the scanf if i get a seg fault. plz take a look.

Code:

   FILE *in_file = NULL;                             /* Declare global batch read in file handler */
   char user_file[STR_MAX];                          /* Declare temporary variable to hold user input */
   int goods = 0, bads = 0, eof_test = FALSE;        /* Declare temporary counting variables */
   int a = 0, b = 0, c = 0, d = 0, e = 0, f = 0;     /* Declare temporary counting variables */
   printf("\nAutomatic Mode Is Running...\n\n");     /* Display opening message */
   good_file = fopen("address_book.txt", "w");       /* Open file for correct output using write parameter */
   bad_file = fopen("errors.txt", "w");              /* Open file for incorrect output using write parameter */
   printf("Please enter the filename of your address book: >> "); /* Ask user for input file name */
   scanf("%s", &user_file);                          /* Take line of input from user for file name */
   if((in_file = fopen("a.txt", "r")) == NULL)     /* Check if read file is corrupted */
   {                                                 /* Start if statement */
      printf("\nCannot open input file, please check the filename try again.\n\n"); /* Print error message */
      exit(1);                                       /* Exit after input file error */
   }                                                 /* End if statement */
   z = fgetc(in_file);                               /* Gather character from file to temporary variable */
   while(eof_test == FALSE)                          /* Continue read loop while end of file is not found */
   {                                                 /* Start while loop */
      for(a = 0; a < MAX; a++)                       /* Run loop until maximum address book size */
      {                                              /* Start for loop */
         rester();                                   /* Call to reset word test variables */
         for(b = 0; b < UNIT_MAX; b++)               /* Run loop until maximum unit size */
            if((z == ' ') && (start == FALSE))       /* Check if read in character is a space */
            {                                        /* Start if statement */
               b--;                                  /* Reset counter back one to allow space */
            }                                        /* End if statement */
            else if((z >= '0') && (z <= '9'))        /* Check if first character is a house number */
            {                                        /* Start if statement */
               fptr->number[a][0] = z;               /* Move read in character into struct */
               house = TRUE;                         /* Set test for house or unit to true */
               break;                                /* Break from unit loop if its a house */
            }                                        /* End if statement */
            else                                     /* Else read in character is not a space */
            {                                        /* Start else statement */
               start = TRUE;                         /* Set started to true if word has begun */
               if((z == ' ') && (start == TRUE))     /* Check if character is a space and word has started */
               {                                     /* Start if statement */
                  end = TRUE;                        /* Set end to true if at end of word */
               }                                     /* End if statement */
               else                                  /* Else character is letter in word */
               {                                     /* Start else statement */
                  fptr->flat_unit[a][b] = z;         /* Move read in character into struct */
               }                                     /* End else statement */
            }                                        /* End else statement */
            z = fgetc(in_file);                      /* Gather character from file to temporary variable */
         }                                           /* End for loop */
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