#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define DELETED_RECORD '*'
#define USABLE_RECORD ' '

#define NUMERIC_FIELD     'N'
#define CHARACTER_FIELD   'C'
#define LOGICAL_FIELD     'L'
#define MEMO_FIELD        'M'
#define DATE_FIELD        'D'
#define FLOAT_FIELD       'F'
#define PICTURE_FIELD     'P'

#pragma pack(1)
typedef struct   {

	 unsigned int   bfVersion:7;
    unsigned int   bfHasMemo:1;
    unsigned int   bYear:8;
    unsigned char  bMonth;
    unsigned char  bDay;
    long int       lNumberRecords;
    short int      nFirstRecordOffset;
	 short int      nRecordLength;
    unsigned char  szReserved[20];
	 } DB3HEADER;
typedef struct   {
    char           szColumnName[11];
    char           chType;
    long           lFieldPointer;
    unsigned char  byLength;
    unsigned char  byDecimalPlace;
    char           szReserved[14];
	 } COLUMNDEF;
	 int    main()
{
FILE    *DBFile;
DB3HEADER   db3Header;
struct _DBRECORD {
	 char    sStatus[1];
    char    sName[40];
    char    sAddr1[40];
    char    sAddr2[40];
	 char    sCity[20];
    char    sState[2];
    char    sZip[5];
    } OurRecord;
char        *pOurRecord;
COLUMNDEF   ColumnDef[6];
char        szBuffer[200];
char        szTime[26];
char        szFileName[25];
int         i;
int         nColumnCount = 0;
int         nResult;
long        lCurrentRecord = 0;
double      dSales = 0.0;
struct tm   *NewTime;
time_t      aClock;

	 printf("Please enter new database name: ");
    gets(szFileName);
	 DBFile = fopen(szFileName, "wb");
	 if (DBFile == NULL)
    {
        fprintf(stderr,
				"ERROR: File '%s' couldn't be opened.\n", szFileName);
        exit(4);
    }

	 time( &aClock );
	 NewTime = localtime(&aClock);
    memset(&db3Header, 0, sizeof(db3Header));

	 db3Header.bfVersion = 3;

    db3Header.bfHasMemo = 0;

    db3Header.bYear = NewTime->tm_year;
    db3Header.bMonth = (unsigned char)(NewTime->tm_mon + 1);
    db3Header.bDay   = (unsigned char)NewTime->tm_mday;

	 db3Header.lNumberRecords = 0;

    db3Header.nFirstRecordOffset = sizeof(DB3HEADER) + sizeof(ColumnDef)
   + 2;

    db3Header.nRecordLength = sizeof(OurRecord);
    nResult = fwrite((char *)&db3Header,
		  sizeof(DB3HEADER),
        1,
		  DBFile);
    if (nResult != 1)
    {
		  fprintf(stderr, "ERROR: File '%s', write error (Database \
header).\n",
            szFileName);
		  fclose(DBFile);
        exit(4);
	 }

    memset(ColumnDef, 0, sizeof(ColumnDef));

	 strcpy(ColumnDef[0].szColumnName, "Name");
	 ColumnDef[0].chType = CHARACTER_FIELD;
	 ColumnDef[0].byLength = sizeof(OurRecord.sName);
	 ColumnDef[0].byDecimalPlace = 0;
	 strcpy(ColumnDef[1].szColumnName, "Address1");
	 ColumnDef[1].chType = CHARACTER_FIELD;
	 ColumnDef[1].byLength = sizeof(OurRecord.sAddr1);
    ColumnDef[1].byDecimalPlace = 0;
	 strcpy(ColumnDef[2].szColumnName, "Address2");
	 ColumnDef[2].chType = CHARACTER_FIELD;
	 ColumnDef[2].byLength = sizeof(OurRecord.sAddr2);
	 ColumnDef[2].byDecimalPlace = 0;
	 strcpy(ColumnDef[3].szColumnName, "City");
	 ColumnDef[3].chType = CHARACTER_FIELD;
	 ColumnDef[3].byLength = sizeof(OurRecord.sCity);
	 ColumnDef[3].byDecimalPlace = 0;
	 strcpy(ColumnDef[4].szColumnName, "State");
	 ColumnDef[4].chType = CHARACTER_FIELD;
	 ColumnDef[4].byLength = sizeof(OurRecord.sState);
	 ColumnDef[4].byDecimalPlace = 0;
	 strcpy(ColumnDef[5].szColumnName, "Zipcode");
	 ColumnDef[5].chType = CHARACTER_FIELD;
	 ColumnDef[5].byLength = sizeof(OurRecord.sZip);
	 ColumnDef[5].byDecimalPlace = 0;
	 nResult = fwrite((char *)ColumnDef,
		  sizeof(ColumnDef),
		  1,
		  DBFile);
	 if (nResult != 1)
	 {
		  fprintf(stderr, "ERROR: File '%s', write error (Column \
headers).\n",
				szFileName);
		  fclose(DBFile);
		  exit(4);
	 }

  nResult = fwrite((char *)"\x0D\0",
        sizeof(char) * 2,
        1,
        DBFile);
	 if (nResult != 1)
    {
		  fprintf(stderr, "ERROR: File '%s', write error (Column \
headers).\n",
				szFileName);
		  fclose(DBFile);
		  exit(4);
	 }
	 db3Header.nFirstRecordOffset = (int)ftell(DBFile);
/* Step 5. Get some records for the database. */
	 memset(&OurRecord, 0, sizeof(OurRecord));
	 printf("Enter the name: (or no name to end)");
	 gets(szBuffer);
	 strncpy(OurRecord.sName, szBuffer, sizeof(OurRecord.sName));
	 while (strlen(szBuffer) > 0)
	 {
		  OurRecord.sStatus[0] = USABLE_RECORD;
		  printf("Enter address line 1: ");
		  gets(szBuffer);
		  strncpy(OurRecord.sAddr1, szBuffer, sizeof(OurRecord.sAddr1));
		  printf("Enter address line 2:");
		  gets(szBuffer);
		  strncpy(OurRecord.sAddr2, szBuffer, sizeof(OurRecord.sAddr2));
		  printf("Enter city:");
         gets(szBuffer);
        strncpy(OurRecord.sCity, szBuffer, sizeof(OurRecord.sCity));
		  printf("Enter state (2 characters only):");
		  gets(szBuffer);
		  strncpy(OurRecord.sState, szBuffer, sizeof(OurRecord.sState));
		  printf("Enter Zipcode:");
		  gets(szBuffer);
		  strncpy(OurRecord.sZip, szBuffer, sizeof(OurRecord.sZip));

		  pOurRecord = (char *)&OurRecord;
		  for (i = 0; i < sizeof(OurRecord); i++)
		  {
				if (pOurRecord[i] == '\0')
				{
					 pOurRecord[i] = ' ';
				}
		  }
		  nResult = fwrite((char *)&OurRecord,
				sizeof(OurRecord),
				1,
				DBFile);
		  if (nResult != 1)
		  {
				fprintf(stderr, "ERROR: File '%s', write error (Column \
	 headers).\n",
					 szFileName);
				fclose(DBFile);
				exit(4);
		  }
        else
		  {
        ++db3Header.lNumberRecords;
		  }
		  memset(&OurRecord, 0, sizeof(OurRecord));
		  printf("Enter the name: (or no name to end)");
        gets(szBuffer);
        strncpy(OurRecord.sName, szBuffer, sizeof(OurRecord.sName));
	 }

    time( &aClock );
	 NewTime = localtime(&aClock);
    /* Set the date to now */
	 db3Header.bYear = NewTime->tm_year;
    db3Header.bMonth = (unsigned char)(NewTime->tm_mon + 1);
    db3Header.bDay   = (unsigned char)NewTime->tm_mday;
	 /* The number of records is already set */
	 nResult = fseek(DBFile, (long)0, SEEK_SET);
    if (nResult != 0)
    {
		  fprintf(stderr, "ERROR: File '%s', seek error (rewrite of \
header).\n",
				szFileName);
		  fclose(DBFile);
		  exit(4);
	 }
	 nResult = fwrite((char *)&db3Header,
		  sizeof(DB3HEADER),
		  1,
		  DBFile);
	 if (nResult != 1)
	 {
		  fprintf(stderr, "ERROR: File '%s', write error (Database header \
rewrite).\n",
				szFileName);
		  fclose(DBFile);
		  exit(4);
	 }

	 fclose(DBFile);
	 return(0);
}