chsize(2)              (XENIX Compatibility Package)              chsize(2)


   NAME
         chsize - changes the size of a file

   SYNOPSIS
         cc [flag ...] file ... -lx
         int chsize (int fildes, long size);

   DESCRIPTION
         fildes is a file descriptor obtained from a create, open, dup, fcntl,
         or pipe system call.  chsize changes the size of the file associated
         with the file descriptor fildes to be exactly size bytes in length.
         The routine either truncates the file, or pads it with an appropriate
         number of bytes.  If size is less than the initial size of the file,
         then all allocated disk blocks between size and the initial file size
         are freed.

         The maximum file size as set by ulimit(2) is enforced when chsize is
         called, rather than on subsequent writes.  Thus chsize fails, and the
         file size remains unchanged if the new changed file size would exceed
         the ulimit.

   DIAGNOSTICS
         Upon successful completion, a value of 0 is returned.  Otherwise, the
         value -1 is returned and errno is set to indicate the error.

   SEE ALSO
         creat(2), dup(2), lseek(2), open(2), pipe(2), ulimit(2)

   NOTES
         In general if chsize is used to expand the size of a file, when data
         is written to the end of the file, intervening blocks are filled with
         zeros.  In a some cases, reducing the file size may not remove the
         data beyond the new end-of-file.




















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