fread(3S)           (C Programming Language Utilities)            fread(3S)


   NAME
         fread, fwrite - binary input/output

   SYNOPSIS
         #include <stdio.h>

         sizet fread (void *ptr, sizet size, sizet nitems,
                       FILE *stream);

         sizet fwrite (const void *ptr, sizet size, sizet nitems,
                       FILE *stream);

   DESCRIPTION
         fread reads into an array pointed to by ptr up to nitems items of
         data from stream, where an item of data is a sequence of bytes (not
         necessarily terminated by a null byte) of length size.  fread stops
         reading bytes if an end-of-file or error condition is encountered
         while reading stream, or if nitems items have been read.  fread
         increments the data-pointer in stream to point to the byte following
         the last byte read if there is one.  fread does not change the
         contents of stream.  fread returns the number of items read.

         fwrite writes to the named output stream at most nitems items of data
         from the array pointed to by ptr, where an item of data is a sequence
         of bytes (not necessarily terminated by a null byte) of length size.
         fwrite stops writing when it has written nitems items of data or if
         an error condition is encountered on stream.  fwrite does not change
         the contents of the array pointed to by ptr.  fwrite increments the
         data-pointer in stream by the number of bytes written.  fwrite
         returns the number of items written.

         If size or nitems is zero then fread and fwrite return a value of 0
         and do not effect the state of stream.

         The ferror or feof routines must be used to distinguish between an
         error condition and end-of-file condition.

   SEE ALSO
         exit(2), lseek(2), read(2), write(2), abort(3C), fclose(3S),
         fopen(3S), getc(3S), gets(3S), printf(3S), putc(3S), puts(3S),
         scanf(3S), stdio(3S).

   DIAGNOSTICS
         If an error occurs the error indicator for stream is set.









   7/91                                                                 Page 1