What function can be used to detect when the end of an input file has been reached?

getc() or feof() in c/c++.

Explanation:

getc() returns EOF(End of File) when the end of the file reached is reached but it is not efficient because it also return EOF when it fails.

feof() returns non-zero value when the EOF is reached otherwise it return 0.So feof() is an efficient method to read a file.

For example:-

#include <stdio.h>    

int main()  

{  

 FILE *f = fopen("sample.txt", "r");  

 int c = getc(f);  

 while (c!= EOF)  

 {  

    putchar(ch);  

   ch = getc(f);  

 }  

 if (feof(f))  

    printf("\n File has ended.");  

 else  

    printf("\n Reading not happened.");  

 fclose(f);

 getchar();  

 return 0;  

}