ferror
Tests for an error on a stream.
intferror(FILE*stream);
| Function | Required Header | Compatibility |
| ferror | <stdio.h> | ANSI, Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
If no error has occurred on stream, ferror returns 0. Otherwise, it returns a nonzero value.
Parameter
stream
Pointer to FILE structure
Remarks
The ferror routine (implemented both as a function and as a macro) tests for a reading or writing error on the file associated with stream. If an error has occurred, the error indicator for the stream remains set until the stream is closed or rewound, or until clearerr is called against it.
Example
/* FEOF.C: This program uses feof to indicate when
* it reaches the end of the file FEOF.C. It also
* checks for errors with ferror.
*/
#include <stdio.h>
#include <stdlib.h>
void main( void )
{
int count, total = 0;
char buffer[100];
FILE *stream;
if( (stream = fopen( "feof.c", "r" )) == NULL )
exit( 1 );
/* Cycle until end of file reached: */
while( !feof( stream ) )
{
/* Attempt to read in 10 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 );
}
Output
Number of bytes read = 745