Question

Here is a simple code to print all characters of a txt file on screen:

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main() {
       int **i;
       int j,k;
       char a;
    ifstream test("test.txt", ios::binary);
    while((a=test.get())!=-1)//if I use "while(!test.eof())" here, how to avoid the output of the last character(-1) to std::cout, or any ostream objects?
    {
   putchar(a);//also change this to putchar(test.get());
    }
       getchar();
}

As I noted in the code, if I use “test.eof()” to judge the end of test.txt, I’ll always get an extra blank at the end of the output. How to avoid it?

Answer 1

You want:

int a;

The get() function returns an int, not a char – this is the same in C – when using getchar(), you read into an int variable not char. So your loop looks like:

while( ( a = test.get() ) != EOF )

note you want EOF here, not eof(). a version using eof() would look like this:

char c;
while( test.get( c ) ) {
   putchar( c );   // or whatever
}

if ( test.eof() ) {
  // Ok, we finished because of end of file
}
else {
  // finished not because of end of file - probably an error
}