feof, ferror, clearerr, fileno

Purpose

     Checks the status of a stream.

Library

     Standard I/O Library (libc.a)

Syntax

     #include <stdio.h>

     int feof (stream)                         void clearerr (stream)
     FILE *stream;                             FILE *stream;

     int ferror (stream)                       int fileno (stream)
     FILE *stream;                             FILE *stream;
     Description

     These macros inquire about the status of a stream.

     The feof  macro inquires  about end-of-file.  If  EOF has
     previously been detected reading  the input stream speci-
     fied  by  the  stream   parameter,  a  nonzero  value  is
     returned.  Otherwise, a value of 0 is returned.

     The ferror macro inquires  about input/output errors.  If
     an I/O error has previously occurred when reading from or
     writing to the stream  specified by the stream parameter,
     a nonzero value is returned.   Otherwise, a value of 0 is
     returned.

     The clearerr macro resets the error indicator and the EOF
     indicator to  0 for  the stream  specified by  the stream
     parameter.

     The  fileno macro  returns  the  integer file  descriptor
     associated with the input pointed to by the stream param-
     eter.

     Note:  Since  these routines  are implemented  as macros,
     they cannot be declared or redeclared.

     Related Information

     In  this book:   "open,"  "fopen,  freopen, fdopen,"  and
     "standard i/o library."