Thread: file input and output

/*
This program is to input wizard detail into disk, display all the wizard details and search for particular wizard detail using wizardID or name. How to solve my problem as stated below?
My display function also cannot work... PLEASE help to solve my problem.
*/

/**************************************************/

#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<stdlib.h>

#define false 0
#define true 1

void add();
void display();
void search();
void remove();

FILE *MyFile;
int bytesWritten;
int bytesRead;
char wanted[10]; //If this is int, then my file input and output
char found; // is working correctly.

struct WizardStructure
{
char Name[30], Magic[100];
char WizardID[10]; //If this is int, then my file input and
}Wizard; //output is working correctly.

/************************************************** */

void main()
{

}

/************************************************** */

void add()
{
MyFile = fopen("Wizard.dat", "r+b");

if (!MyFile)
MyFile = fopen("Wizard.dat", "w+b");

printf("\n Enter Wizard name : ");
scanf(" %[^\n]", Wizard.Name);
printf("\n Enter Wizard ID : ");
scanf(" %]^\n]", Wizard.WizardID); //question as above
printf("\n Enter MAGIC POWER of the Wizard : ");
scanf(" %[^\n]", Wizard.Magic);

fseek (MyFile, 0, SEEK_END);

bytesWritten = fwrite((void*)&Wizard, sizeof(Wizard), 1, MyFile);
fclose (MyFile);
}

/************************************************** */

void display()
{
fprintf(stdout, "\n Wizard Name\t\t Wizard ID\t\t Wizard Magic");
fprintf(stdout, "\n ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~");

FILE *MyFile;
MyFile = fopen ("Wizard", "r+b");
if (fseek (MyFile, 0, SEEK_SET) == 0 );
{
bytesRead = fread ((void*) & Wizard, 1, sizeof(Wizard), MyFile);
while ( !feof (MyFile))
{
fprintf(stdout, "\n %s\t\t\t %s\t\t\t %s", Wizard.Name, Wizard.WizardID, Wizard.Magic);
bytesRead = fread ((void*) & Wizard, 1, sizeof(Wizard), MyFile);
}
}
}

/************************************************** */

void search()
{
MyFile = fopen ("Wizard.dat", "r+b");

printf("\n Enter Wizard's ID : ");
gets (wanted);

fseek (MyFile, 0, SEEK_SET);

found = false;

while (( !feof (MyFile)) && (found != true))
{
bytesRead = fread ((void*) & MyFile, sizeof (MyFile), 1, MyFile);
if (bytesRead > 0)
if ("Wanted" == "Wizard.WizardID") //question as
found = true; //above
}

if (found == true)
{
printf("\n WizardID : %s", Wizard.WizardID);
printf("\n Name : %s", Wizard.Name);
printf("\n Wizard's Magic : %s", Wizard.Magic);
}
else
printf("\n WizardID is not found");
fclose(MyFile);
}

Some help:

1. void main is wrong; use int main
2. fopen returns a value; ALWAYS check this value
3. don't use gets; use fgets instead (it's safer)
4. be carefull with using scanf and gets functions in the same program (scanf leaves the newline chars in your input buffer).
5. use CODE TAGS
6. it's not working because your main function is empty

Cheers,
Monster

I used to use void main(void) myself before I started using comman-line options. What's the reasoning behind it?