ferror man page


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

ferror — test error indicator on a stream


#include <stdio.h>

int ferror(FILE *stream);


The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1‐2008 defers to the ISO C standard.

The ferror() function shall test the error indicator for the stream pointed to by stream.

The ferror() function shall not change the setting of errno if stream is valid.

Return Value

The ferror() function shall return non-zero if and only if the error indicator is set for stream.


No errors are defined.

The following sections are informative.

See Also

clearerr(), feof(), fopen()

The Base Definitions volume of POSIX.1‐2008, <stdio.h>


2013 IEEE/The Open Group POSIX Programmer's Manual