feof
Tests for end-of-file on a stream.
int feof(
FILE *stream
);
Parameters
- stream
Pointer to FILE structure.
Return Value
The feof function returns a nonzero value if a read operation has attempted to read past the end of the file; it returns 0 otherwise. If the stream pointer is NULL, the function invokes the invalid parameter handler, as described in Parameter Validation. If execution is allowed to continue, errno is set to EINVAL and the feof returns 0.
See _doserrno, errno, _sys_errlist, and _sys_nerr for more information on these, and other, error codes.
Remarks
The feof routine (implemented both as a function and as a macro) determines whether the end of stream has been passed. When the end of file is passed, read operations return an end-of-file indicator until the stream is closed or until rewind, fsetpos, fseek, or clearerr is called against it.
For example, if a file contains 10 bytes and you read 10 bytes from the file, feof will return 0 because, even though the file pointer is at the end of the file, you have not attempted to read beyond the end. Only after you try to read an 11th byte will feof return a nonzero value.
Requirements
Function |
Required header |
|---|---|
feof |
<stdio.h> |
For additional compatibility information, see Compatibility in the Introduction.
Example
// crt_feof.c
// This program uses feof to indicate when
// it reaches the end of the file CRT_FEOF.TXT. It also
// checks for errors with ferror.
//
#include <stdio.h>
#include <stdlib.h>
int main( void )
{
int count, total = 0;
char buffer[100];
FILE *stream;
fopen_s( &stream, "crt_feof.txt", "r" );
if( stream == NULL )
exit( 1 );
// Cycle until end of file reached:
while( !feof( stream ) )
{
// Attempt to read in 100 bytes:
count = fread( buffer, sizeof( char ), 100, stream );
if( ferror( stream ) ) {
perror( "Read error" );
break;
}
// Total up actual bytes read
total += count;
}
printf( "Number of bytes read = %d\n", total );
fclose( stream );
}
Input: crt_feof.txt
Line one.
Line two.
Output
Number of bytes read = 19
.NET Framework Equivalent
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.