FREAD(3S-SVR4)      RISC/os Reference Manual       FREAD(3S-SVR4)



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 ter-
     minated by a null byte) of length size.  fwrite stops writ-
     ing 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 incre-
     ments 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.









                        Printed 11/19/92                   Page 1