chsize(2)                 SYSTEM CALLS                  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.   Oth-
     erwise,  the  value -1 is returned and errno is set to indi-
     cate 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.




















            Last change: XENIX Compatibility Package            1