After executing following code when I enter full name(eg:- "fjh jkgfv") with spaces after choosing II option(Write) I am stuck in an infinite loop.I think it is problem related to some input buffer.Can you please explain the error.Thanks.....
CODE

class File
{
private:
struct rec
{
char name[20];
int age;
rec()
{
age = 0;
}
}p;
fstream file;
public:
File()
{
file.open("/home/puneet/Desktop/temp.dat",ios::binary|ios::in|ios:ut|ios::app);
if(!file)
{
cerr<<"Error opening the file"<<endl;
cerr<<"Press any key to exit . . . . . ."<<endl;
getchar();
exit(1);
}
}

~File()
{
file.close();
}

void Read()
{
file.clear();

if(file.eof() == false)
{
file.read((char *)&p,sizeof(p));
cout<<"Record"<<(file.tellg()/sizeof(p))<<":"<<endl;
cout<<"Name "<<p.name<<endl;
cout<<"Age "<<p.age<<endl<<endl;
}
}

void Write()
{
file.clear();

file.seekp(0L,ios::end);

cout<<"Your name "<<endl;
cin.getline(p.name,20); // Expected error in input & stucks in infinite loop

cout<<"Your age"<<endl;
cin>>p.age;

file.write((char *)&p,sizeof(p));
}

void Display()
{
file.clear();
file.seekg(0L,ios::beg);

while(file.read((char *)&p,sizeof(p)))
{
cout<<"Record"<<(file.tellg()/sizeof(p))<<":"<<endl;
cout<<"Name "<<p.name<<endl;
cout<<"Age "<<p.age<<endl<<endl;
}
}
};

int main()
{
File writer;
while(true)
{
system("clear");
cout<<"1.Read next account"<<endl;
cout<<"2.Write an account at the end"<<endl;
cout<<"3.Display all the records"<<endl;
cout<<"4.Exit"<<endl;
int choice = 0;
cin>>choice;

switch(choice)
{
case 1:
system("clear");
writer.Read();
cout<<"\n\nPress any key to exit . . . . . ."<<endl;
getchar();
break;
case 2: // Choose this option
system("clear");
writer.Write();
cout<<"\n\nPress any key to exit . . . . . ."<<endl;
getchar(); // Not executed
break;
case 3:
system("clear");
writer.Display();
cout<<"\n\nPress any key to exit . . . . . ."<<endl;
getchar();
break;
case 4:
return 0;
default:
break;
}
}
return 0;
}

Try changing while(file.read((char *)&p,sizeof(p))) to while(file.read((char *)&p,sizeof(p)).good()). The implicit conversion to void* only returns NULL for errors, not EOF.
Kevin Barry

Thanks for this information but problem was in "Write" function.I tried using cin.ignore() after "cin>>choice" in main() function after cout statements.And my problem was solved.Does it mean that after using "cin>>some_var" -> '\n' remains in input stream and "getline" takes this as input(in Write() getline(p.name,20)) and goes to next getline?? Please correct me if I am wrong....

getline() will read up to the first newline character found; and yes, there is a newline in the input stream under the scenario you described, thus getline() will return immediately.

You can remove the unwanted newline (and any unwanted characters leading up to it) using ignore(). Something like:

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