ferror.3s

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3S 代码 · 共 73 行

.\" SCCSID: @(#)ferror.3s	2.1	3/10/87
.TH ferror 3s 
.SH Name
ferror, feof, clearerr, fileno \- stream status inquiries
.SH Syntax
.B #include <stdio.h>
.PP
.B feof(stream)
.br
.SM
.B FILE
.B *stream;
.PP
.B ferror(stream)
.br
.SM
.B FILE
.B *stream
.PP
.B void clearerr(stream)
.br
.SM
.B FILE
.B *stream
.PP
.B fileno(stream)
.br
.SM
.B FILE
.B *stream;
.SH Description
.NXR "ferror subroutine"
.NXR "feof subroutine"
.NXR "clearerr subroutine"
.NXR "fileno subroutine"
.NXR "stream" "status queries"
The
.PN ferror
function returns nonzero when an error has 
occurred reading or writing the named
.IR stream ,
otherwise zero.
Unless cleared by
.PN clearerr ,
the error indication lasts until
the stream is closed.
.PP
The
.PN feof
function returns nonzero when end of file is read on the named input
.IR stream ,
otherwise zero.
.PP
The
.PN clearerr
function resets both the error and EOF
indicators on the named
.IR stream .
.PP
The
.PN fileno
function returns the integer file descriptor
associated with the
.IR stream ,
see
.MS open 2 .
.PP
These functions
are implemented as macros;
they cannot be redeclared.
.SH See Also
open(2), fopen(3s)