ferror.md

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ferror

Tests for an error on a stream.

Syntax

int ferror(
   FILE *stream
);

Parameters

stream
Pointer to FILE structure.

Return value

If no error has occurred on stream, ferror returns 0. Otherwise, it returns a nonzero value. If stream is NULL, ferror invokes the invalid parameter handler, as described in Parameter validation. If execution is allowed to continue, this function sets errno to EINVAL and returns 0.

For more information about return codes, see errno, _doserrno, _sys_errlist, and _sys_nerr.

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.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Function	Required header
ferror	<stdio.h>

For more compatibility information, see Compatibility.

Example

See the example for feof.

See also

Error handling
Stream I/O
clearerr
_eof
feof
fopen, _wfopen
perror, _wperror