fread(3S)               LIBRARY FUNCTIONS               fread(3S)



NAME
     fread, fwrite - binary input/output

SYNOPSIS
     #include <stdio.h>

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

     size_t fwrite (const void *ptr, size_t size, size_t 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.












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