Hsiang2k
asked on
Help!!!!!Problem with creating binary file.
I have a problem.I want to create a binary file and write to it.I have this code:
CFile f;
CFileException e;
if (f.Open(FullPath, CFile::modeCreate | CFile::typeBinary | CFile::modeWrite , &e))
{
//f.WriteString(m_password
//f.WriteString("\n");
f.Write("test",4);
f.Close();
}
But when i run this programm and open bin file with notepad i see usual text file.What i do wrong?
This file is supposed to contain password and i want the file to contain weird characters when somebody open it with Notepad.
Thank to everybody.
CFile f;
CFileException e;
if (f.Open(FullPath, CFile::modeCreate | CFile::typeBinary | CFile::modeWrite , &e))
{
//f.WriteString(m_password
//f.WriteString("\n");
f.Write("test",4);
f.Close();
}
But when i run this programm and open bin file with notepad i see usual text file.What i do wrong?
This file is supposed to contain password and i want the file to contain weird characters when somebody open it with Notepad.
Thank to everybody.
ASKER CERTIFIED SOLUTION
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//////////////////////////
// COPYRIGHT : LOH HON CHUN //
//////////////////////////
// binaryfile.cpp
// demonstrates how to use binary files for reading and writing
// include necessary pre-defined header files
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
// structure for employee record
typedef struct EMPDATA
{
int number;
char name[16];
char sex;
int salary;
} EMPDATA;
// function prototypes
int draw_menu(void);
void err_msg(int type);
int read_record(void);
int write_record(void);
// main program entry point
int main(void)
{
int option_selected=0;
int exit_status=0;
// exit program if user chooses to exit or file opening in binary mode fails
while ( option_selected != 3 && exit_status != 1 )
{
// get input from user to read or write records
option_selected = draw_menu();
// if user chooses to read record
if ( option_selected == 1 )
{
exit_status = read_record();
}
// if user chooses to write record
else if ( option_selected == 2 )
{
exit_status = write_record();
}
}
return exit_status;
}
// draw the main menu and return the an integer to indicate the option selected by user
int draw_menu(void)
{
char option_selected;
// read input
while ( true )
{
system("cls");
// draw the menu
puts("1. Read record");
puts("2. Write record");
puts("3. Exit");
printf("Enter your choice > ");
fflush(stdin);
// read input
option_selected = getchar();
if ( option_selected == '1' || option_selected == '2' ||
option_selected == '3'
)
{
break;
}
else
{
puts("\n>> Invalid option!");
printf("Press <ENTER> to continue ");
fflush(stdin);
getchar();
}
}
// minus 48 to obtain either 1, 2, or 3
return (option_selected - 48);
}
// display an error message dialog box
void err_msg(int type)
{
switch ( type )
{
case 1 :// formatted message box for error message
MessageBox(NULL,
"Fatal Error: There are no records to read\n"\
" Application terminated",
"Fatal Error",
MB_OK|MB_ICONERROR
);
break;
case 2 :// formatted message box for error message
MessageBox(NULL,
"Fatal Error: Error opening file in binary mode\n"\
" Application terminated",
"Fatal Error",
MB_OK|MB_ICONERROR
);
break;
}
}
// reads record from file
int read_record(void)
{
int count=0;
int num_record;
EMPDATA empdata[1];
FILE *fp;
system("cls");
// if file opening in binary mode fails
if ( (fp = fopen("data.dat", "rb")) == NULL )
{
err_msg(1);
// 1: EXIT_FAILURE
return 1;
}
// if file opening in binary mode is successful
else
{
///////////////////////
/// NOTE ///
///////////////////////
//////////////////////////
// THE FIRST METHOD IS THE BETTER METHOD TO USE //
//////////////////////////
//////////////////////////
// begining of ALTERNATIVE BLOCK 1 //
//////////////////////////
fseek(fp, 0, SEEK_END);
num_record = int(ftell(fp)) / (sizeof(EMPDATA));
fseek(fp, 0, SEEK_SET);
fread(empdata, sizeof(empdata), 1, fp);
while ( num_record-- )
//////////////////////////
// end of ALTERNATIVE BLOCK 1 //
//////////////////////////
//////////////////////////
// begining of ALTERNATIVE BLOCK 2 //
//////////////////////////
while ( !(feof(fp)) )
//////////////////////////
// end of ALTERNATIVE BLOCK 2 //
//////////////////////////
{
// print records
printf(">> Retrieving record %d\n", ++count);
Sleep(250);
printf(" >File position marker = %ld\n\n", ftell(fp));
Sleep(100);
printf(" Employee number: %02d\n", empdata[0].number);
Sleep(100);
printf(" Employee name : %s\n", empdata[0].name);
Sleep(100);
printf(" Employee sex : %c\n", empdata[0].sex);
Sleep(100);
printf(" Employee salary: %d\n\n", empdata[0].salary);
printf("Press <ENTER> to continue......");
fflush(stdin);
getchar();
printf("\n");
// read next record
fread(empdata, sizeof(empdata), 1, fp);
}
// close file pointer
fclose(fp);
// 0: EXIT_SUCCESS
return 0;
}
}
// write records onto file
int write_record(void)
{
int count;
long file_position;
char tocontinue='y';
EMPDATA empdata[1];
FILE *fp;
system("cls");
// if file opening in binary mode fails or creation of file fails in the case
// if file does not exits in the first place
if ( (fp = fopen("data.dat", "ab")) == NULL )
{
err_msg(2);
// 1: EXIT_FAILURE
return 1;
}
// if file opening in binary mode is successful
else
{
fseek(fp, 0, SEEK_END);
file_position = ftell(fp);
count = int(file_position) / sizeof(empdata);
printf("There are %d existing records in database.\n", count);
while ( tocontinue == 'y' )
{
printf(">> Enter fields for record %d\n", ++count);
empdata[0].number = count;
printf(" >Enter employee's name : ");
fflush(stdin);
gets(empdata[0].name);
while ( true )
{
printf(" >Enter employee's sex: ");
fflush(stdin);
empdata[0].sex = toupper(getchar());
// if user enters an invalid sex
if ( empdata[0].sex != 'M' && empdata[0].sex != 'F' )
printf(" Invalid sex!\n");
// if user enters a valid sex
else
break;
}
while ( true )
{
printf(" >Enter employee's salary: ");
fflush(stdin);
// user do not enter an integer for salary
if ( scanf("%d", &empdata[0].salary) == 0 )
{
printf(" Invalid salary!\n");
}
// if user enters an integer for salary
else
{
break;
}
}
// write record into binary file
fwrite(empdata, sizeof(empdata), 1, fp);
// prompt user whether to continue entering next record
do
{
printf("\n>> Enter next record (y/n)? ");
fflush(stdin);
tocontinue = tolower(getchar());
if ( tocontinue != 'y' && tocontinue != 'n' )
printf(" Invalid input");
} while ( tocontinue != 'y' && tocontinue != 'n' );
}
// close file pointer
fclose(fp);
// 0: EXIT_SUCCESS
return 0;
}
}
hongjun