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| .\" and Copyright (C) 2021 Michael Kerrisk <mtk.manpages@gmail.com> |
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| .\" @(#)ferror.3 6.8 (Berkeley) 6/29/91 |
| .\" |
| .\" |
| .\" Converted for Linux, Mon Nov 29 14:24:40 1993, faith@cs.unc.edu |
| .\" |
| .TH FERROR 3 2021-03-22 "" "Linux Programmer's Manual" |
| .SH NAME |
| clearerr, feof, ferror \- check and reset stream status |
| .SH SYNOPSIS |
| .nf |
| .B #include <stdio.h> |
| .PP |
| .BI "void clearerr(FILE *" stream ); |
| .BI "int feof(FILE *" stream ); |
| .BI "int ferror(FILE *" stream ); |
| .fi |
| .SH DESCRIPTION |
| The function |
| .BR clearerr () |
| clears the end-of-file and error indicators for the stream pointed to by |
| .IR stream . |
| .PP |
| The function |
| .BR feof () |
| tests the end-of-file indicator for the stream pointed to by |
| .IR stream , |
| returning nonzero if it is set. |
| The end-of-file indicator can be cleared only by the function |
| .BR clearerr (). |
| .PP |
| The function |
| .BR ferror () |
| tests the error indicator for the stream pointed to by |
| .IR stream , |
| returning nonzero if it is set. |
| The error indicator can be reset only by the |
| .BR clearerr () |
| function. |
| .PP |
| For nonlocking counterparts, see |
| .BR unlocked_stdio (3). |
| .SH RETURN VALUE |
| The |
| .BR feof () |
| function returns nonzero if the end-of-file indicator is set for |
| .IR stream ; |
| otherwise, it returns zero. |
| .PP |
| The |
| .BR feof () |
| function returns nonzero if the error indicator is set for |
| .IR stream ; |
| otherwise, it returns zero. |
| .SH ERRORS |
| These functions should not fail and do not set |
| .IR errno . |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR clearerr (), |
| .BR feof (), |
| .BR ferror () |
| T} Thread safety MT-Safe |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| The functions |
| .BR clearerr (), |
| .BR feof (), |
| and |
| .BR ferror () |
| conform to C89, C99, POSIX.1-2001, and POSIX.1-2008. |
| .SH NOTES |
| POSIX.1-2008 specifies |
| .\"https://www.austingroupbugs.net/view.php?id=401 |
| that these functions shall not change the value of |
| .I errno |
| if |
| .I stream |
| is valid. |
| .SH SEE ALSO |
| .BR open (2), |
| .BR fdopen (3), |
| .BR fileno (3), |
| .BR stdio (3), |
| .BR unlocked_stdio (3) |