C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/listings/v_08_04/8n04073a

Text File | 1990-03-18 | 5.4 KB | 151 lines

*****Listing 2*****
   1:   /*
   2:    *  MDBMAIN.C       (Static Array Only Version)
   3:    *
   4:    *  Program:    Mini-Database
   5:    *  Written by: Leor Zolman
   6:    *  Module:     Main Program Module
   7:    *
   8:    *  Program Description:
   9:    *      This system is an "introductory showcase" of
  10:    *      C programming techniques for File I/O-related
  11:    *      applications. Areas of focus include:
  12:    *          Static and Dynamic Array Allocation
  13:    *          Text-based and Binary-based Disk Data Storage
  14:    *          Elementary user-interface and error-handling
  15:    *
  16:    *  Compile & Link (Turbo C):
  17:    *      tcc mdbmain.c mdbedit.c mdbutil.c
  18:    *                          {mdbftxt.c or mdbfbin.c}
  19:    */
  20:
  21:   #include <stdio.h>
  22:   #include <stdlib.h>
  23:
  24:   #define MAIN_MODULE 1       /* force data definitions   */
  25:   #include "mdb.h"
  26:
  27:
  28:   #define CREATE  1           /* Main menu action codes   */
  29:   #define OPEN    2
  30:   #define EDIT    3
  31:   #define SAVE    4
  32:   #define BAKUP   5
  33:   #define CLOSE   6
  34:   #define ABANDON 7
  35:   #define QUIT    8
  36:
  37:   static struct menu_item main_menu[] =
  38:   {
  39:       {CREATE, "Create New Database"},
  40:       {OPEN, "Select Existing Database to Work With"},
  41:       {EDIT, "Edit Database Records"},
  42:       {SAVE, "Write Database to Disk"},
  43:       {BAKUP, "Backup Database to Floppies"},
  44:       {CLOSE, "Close the Database"},
  45:       {ABANDON, "Abandon Changes to the Current Database"},
  46:       {QUIT, "Quit"},
  47:       {NULL}                          /* End of list              */
  48:   };
  49:
  50:
  51:   main(int argc, char **argv)
  52:   {
  53:       char db_name[150];
  54:       int db_active = FALSE;      /* No Database currently open   */
  55:       FILE *fp;
  56:
  57:       while (1)
  58:       {
  59:           switch(do_menu(main_menu, "Main Menu"))
  60:           {
  61:               case CREATE:
  62:                   if (db_active)
  63:                       goto still_open;
  64:                   printf("Name for new Database? ");
  65:                   gets(db_name);
  66:                   if ((fp = fopen(db_name,"r")) != NULL)
  67:                   {
  68:                       printf("A file by that name already exists.\n");
  69:                       fclose(fp);
  70:                       break;
  71:                   }
  72:                   max_recs = MAX_RECS;
  73:                   db_active = TRUE;
  74:                   n_recs = 0;
  75:                   printf("Database created; entering EDIT mode:\n");
  76:                           /* After creating, fall through to EDIT */
  77:
  78:               case EDIT:
  79:                   if (!db_active)
  80:                       goto inactive;
  81:                   edit_db();  /* Edit records in memory   */
  82:                   break;
  83:
  84:               case OPEN:
  85:                   if (db_active)
  86:                   {
  87:           still_open: printf("Please close the current Database.\n");
  88:                       break;
  89:                   }
  90:                   printf("Database Name? ");
  91:                   gets(db_name);
  92:                   if ((n_recs = read_db(db_name)) != NULL)
  93:                   {
  94:                       printf("\nLoaded %d Record(s).\n", n_recs);
  95:                       db_active = TRUE;
  96:                   }
  97:
  98:                   edit_db();
  99:                   break;
 100:
 101:               case BAKUP:
 102:                   if (!db_active)
 103:                       goto inactive;
 104:                   backup_db();    /* Perform backup       */
 105:                   break;
 106:
 107:               case CLOSE:
 108:                   if (!db_active)
 109:                       goto inactive;
 110:                   write_db(db_name);  /* write to disk    */
 111:                   free_up();
 112:                   db_active = FALSE;
 113:                   break;
 114:
 115:               case SAVE:
 116:                   if (!db_active)
 117:                       goto inactive;
 118:                   write_db(db_name);  /* write to disk    */
 119:                   break;
 120:
 121:               case ABANDON:
 122:                   if (!db_active)
 123:                   {
 124:             inactive: printf("Please select a Database first!\n");
 125:                       break;
 126:                   }
 127:                   free_up();
 128:                   db_active = FALSE;
 129:                   break;
 130:
 131:               case QUIT:
 132:                   if (db_active)
 133:                       goto still_open;
 134:                   exit(0);
 135:           }
 136:       }
 137:   }
 138:
 139:   /*
 140:    * Function:        backup_db
 141:    * Purpose:         Backup current Database to floppies
 142:    * Parameters:      None
 143:    * Return Value:    None
 144:    */
 145:
 146:   void backup_db()        /* Backup module */
 147:   {}
 148:
 149: