We recommend using Visual Studio 2017



The latest version of this topic can be found at _eof.

Tests for end of file (EOF).

int _eof(   
   int fd   


File descriptor referring to the open file.

_eof returns 1 if the current position is end of file, or 0 if it is not. A return value of –1 indicates an error; in this case, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, errno is set to EBADF, which indicates an invalid file descriptor.

The _eof function determines whether the end of the file associated with fd has been reached.

FunctionRequired headerOptional header

For more compatibility information, see Compatibility in the Introduction.

// crt_eof.c  
// This program reads data from a file  
// ten bytes at a time until the end of the  
// file is reached or an error is encountered.  
#include <io.h>  
#include <fcntl.h>  
#include <stdio.h>  
#include <stdlib.h>  
#include <share.h>  
int main( void )  
   int  fh, count, total = 0;  
   char buf[10];  
   if( _sopen_s( &fh, "crt_eof.txt", _O_RDONLY, _SH_DENYNO, 0 ) )  
        perror( "Open failed");  
        exit( 1 );  
   // Cycle until end of file reached:   
   while( !_eof( fh ) )  
      // Attempt to read in 10 bytes:   
      if( (count = _read( fh, buf, 10 )) == -1 )  
         perror( "Read error" );  
      // Total actual bytes read   
      total += count;  
   printf( "Number of bytes read = %d\n", total );  
   _close( fh );  

This file contains some text.  


Number of bytes read = 29  

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

Error Handling
Low-Level I/O
perror, _wperror