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struct linked list problem

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struct linked list problem

 
0
  #1
May 2nd, 2006
Hey guys im reading in a text file with several fields iv tokenized
the '|' so that it only reads the fields categoryId, drinkType, the categoryName, and categoryDescription.

My question is how come when i read the file and copy the reading buffer
"temp" into each struct it does not print out each line in the text file it prints nothing. I traverse through the list and try to print it out?

C0001|H|Espresso Classics|The traditional espresso favourites




C Syntax (Toggle Plain Text) 
  1. int loadData(GJCType* menu, char* menuFile, char* submenuFile)
  2. {
  3.    /*pointer for malloc*/
  4.    CategoryType *newCat, *currentCat, *prevCat;
  5.  
  6.  
  7.  
  8.    /*declaration of variables*/
  9.    int CountNoLines = 0;
  10.    char temp[LINE_LENGTH];
  11.  
  12.    /* variables for tokenizer for menu file*/
  13.    char *catID;
  14.    char *catType;
  15.    char *catName;
  16.    char *catDescription;
  17.    char *delim;
  18.  
  19.    /* declare file pointers to files*/
  20.    FILE *f1;
  21.    FILE *f2;
  22.  
  23.  
  24.    /* opening the menu and submenu for reading*/
  25.    f1 = fopen(menuFile, "r");
  26.    f2 = fopen(submenuFile, "r");
  27.  
  28.    /* check to see if the filuse exists*/
  29.    if(f1 ==NULL || f2 == NULL)
  30.    {
  31.       /* check whether both files have existed or typed in correctly*/
  32.       if(f1 == NULL && f2 == NULL)
  33.       {
  34.  
  35.          printf("Both files do not exist %s %s\n",menuFile,submenuFile);
  36.       }
  37.       /* check for each file existance*/
  38.       else if (f1 == NULL)
  39.       {
  40.          printf("%s does not exist\n\n",menuFile);
  41.       }
  42.       /* check for each file existance*/
  43.       else if(f2 == NULL)
  44.       {
  45.          printf("%s does not exist\n\n", submenuFile);
  46.  
  47.       } 
  48.       printf("EXITING PROGRAM ERROR!\n\n");
  49.       return ERRORCODE; /* cannot proceed*/
  50.    }
  51.  
  52.    /* counts how many fields there are in the file*/
  53.    while(fgets(temp, LINE_LENGTH, f1)!=NULL)
  54.    {
  55.  
  56.  
  57.        newCat = malloc(sizeof(CategoryType));
  58.  
  59.        if(prevCat == NULL)
  60.        {
  61.            menu->headCategory = newCat;
  62.        }
  63.        else
  64.        {
  65.  
  66.  
  67.  
  68.            prevCat->nextCategory = newCat;
  69.  
  70.  
  71.  
  72.            /* stores the catID but also checks if there
  73. 	   is a duplicate*/
  74.  
  75.            catID = strtok(temp, "|");
  76.  
  77. 	   /* checking whether it tokenizez*/
  78. 	   if(catID == NULL)
  79. 	   {
  80. 	      printf("CatID missing\n");
  81. 	   }
  82.  
  83. 	   /*checks for a duplication of the id field*/
  84. 	   if(!checkDuplicationID(menu, catID))
  85. 	   {
  86. 	      return ERRORCODE;
  87. 	   }
  88.            /* gets the second field and tokenizez it*/
  89. 	   catType = strtok(NULL, "|");
  90.  
  91. 	    /* checking whether it tokenizez*/
  92. 	   if(catType == NULL)
  93. 	   {
  94. 	      printf("CatType missing\n");
  95. 	   }
  96.  
  97. 	   catName = strtok(NULL, "|");
  98.  
  99. 	    /* checking whether it tokenizez*/
  100. 	   if(catName == NULL)
  101. 	   {
  102. 	      printf("CatName missing\n");
  103. 	   }
  104. 	   catDescription = strtok(NULL, "\0");
  105.  
  106. 	    /* checking whether it tokenizez*/
  107. 	   if(catDescription == NULL)
  108. 	   {
  109. 	      printf("CatDescription missing\n");
  110. 	   }
  111.  
  112. 	   /* checks the string length of the field*/
  113. 	   if((strlen(catID) >ID_LEN) ||
  114. 	      (strlen(catType) >MAX_NAME_LEN)  ||
  115. 	      (strlen(catDescription) >MAX_DESC_LEN))
  116.  
  117. 	   {	   
  118.  
  119. 	      printf("Wrong data format\n\n");
  120. 	      return ERRORCODE;
  121.  
  122. 	   }
  123.  
  124. 	   strcpy(newCat->categoryID, temp);
  125. 	   newCat->drinkType = temp[0];
  126. 	   strcpy(newCat->categoryName, temp);
  127. 	   strcpy(newCat->categoryDescription, temp);
  128.  
  129.  
  130.  
  131. 	   newCat -> nextCategory = NULL;
  132. 	   newCat->headItem = NULL;
  133. 	   newCat->numItems = 0;
  134. 	   prevCat = newCat;
  135.  
  136. 	   currentCat = menu->headCategory;
  137.  
  138. 	}/* end of if else used to tokenize and copy variables
  139. 	  from and into structs*/     
  140. 	   while(currentCat!=NULL)
  141. 	  {
  142. 	     printf("%s, %c, %s, %s", currentCat->categoryID,
  143. 	     currentCat->drinkType, currentCat->categoryName,
  144. 	     currentCat->categoryDescription);
  145.  
  146. 	     currentCat = currentCat->nextCategory;
  147. 	  }
  148.  
  149.  
  150.  
  151.  
  152.    } /* end of while loop*/   
  153.  
  154.  
  155.  
  156.    /* close both files after reading*/
  157.    if(fclose(f1)!=0 || fclose(f2)!=0)
  158.    {
  159.       fprintf(stderr, "Error in closing files\n");
  160.    }   
  161.  
  162.  
  163.    return EXIT_SUCCESS;
  164. }

C Syntax (Toggle Plain Text) 
  1. #ifndef GJC_H
  2. #define GJC_H
  3.  
  4. /* System-wide header files. */
  5. #include <stdio.h>
  6. #include <stdlib.h>
  7. #include <string.h>
  8. /* System-wide constants. */
  9. #define ID_LEN 5
  10. #define MIN_NAME_LEN 1
  11. #define MAX_NAME_LEN 25
  12. #define MIN_DESC_LEN 1
  13. #define MAX_DESC_LEN 250
  14. #define NUM_PRICES 3
  15. #define HOT 'H'
  16. #define COLD 'C'
  17. #define ERRORCODE 1
  18. #define VALID 0
  19. #define LINE_LENGTH 500
  20. #define TOKEN_PRODUCT 4
  21.  
  22. typedef struct category* CategoryTypePtr;
  23. typedef struct item* ItemTypePtr;
  24.  
  25. /* Structure definitions. */
  26. typedef struct price
  27. {
  28.    unsigned dollars;
  29.    unsigned cents;
  30. } PriceType;
  31.  
  32. typedef struct item
  33. {
  34.    char itemID[ID_LEN + 1];
  35.    char itemName[MAX_NAME_LEN + 1];
  36.    PriceType prices[NUM_PRICES];
  37.    char itemDescription[MAX_DESC_LEN];
  38.    ItemTypePtr nextItem;
  39. } ItemType;
  40.  
  41. typedef struct category
  42. {
  43.    char categoryID[ID_LEN + 1];
  44.    char categoryName[MAX_NAME_LEN + 1];
  45.    char drinkType;      /* (H)ot or (C)old. */
  46.    char categoryDescription[MAX_DESC_LEN];
  47.    CategoryTypePtr nextCategory;
  48.    ItemTypePtr headItem;
  49.    unsigned numItems;
  50. } CategoryType;
  51.  
  52. typedef struct gjc
  53. {
  54.    CategoryTypePtr headCategory;
  55.    unsigned numCategories;
  56. } GJCType;
  57.  
  58. int commandLineArguments(int argc, char* argv[]);
  59. int countToken(FILE *fp, char* temp, int tokenPerLine);
  60. #endif
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Re: struct linked list problem

 
0
  #2
May 2nd, 2006
Your coping the same value (temp) for all the fileds :

C Syntax (Toggle Plain Text) 
  1.    strcpy(newCat->categoryID, temp);
  2.    newCat->drinkType = temp[0];
  3.    strcpy(newCat->categoryName, temp);
  4.    strcpy(newCat->categoryDescription, temp);

You should use the pointers you saved like for example :

C Syntax (Toggle Plain Text) 
  1. strcpy(newCat->categoryDescription, catDescription);



Another thing :
Automatic variables inside a fucntion are initailzed to garabge.
C Syntax (Toggle Plain Text) 
  1. CategoryType *newCat, *currentCat, *prevCat;
You forgot to initalize prevCat before you test it
against a NULL.
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Re: struct linked list problem

 
0
  #3
May 3rd, 2006
thanks got it...
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