truncate(2)							   truncate(2)

NAME
       ftruncate, truncate - truncate a file to a specified length

SYNOPSIS
DESCRIPTION
       The  function  causes  the  regular file referenced by fildes to have a
       size of length bytes.

       The function causes the regular file named by path to have  a  size  of
       length bytes.

       The  effect  of and on other types of files is unspecified. If the file
       previously was larger than length, the extra data is lost.  If  it  was
       previously  shorter  than length, bytes between the old and new lengths
       are read as zeroes. With the file must be open  for  writing;  for  the
       process must have write permission for the file.

       If  the	request would cause the file size to exceed the soft file size
       limit for the process, the request will	fail  and  the	implementation
       will generate the signal for the process.

       These  functions	 do  not  modify  the  file  offset  for any open file
       descriptions associated with the file.  On  successful  completion,  if
       the  file  size	is  changed,  these functions will mark for update the
       st_ctime and st_mtime fields of the file, and if the file is a  regular
       file, the and bits of the file mode may be cleared.

RETURN VALUE
       Upon  successful completion, returns 0. Otherwise a −1 is returned, and
       is set to indicate the error.

ERRORS
       If or fails, is set to one of the following values:

	      A signal was caught during execution.

	      The		     length argument was less than 0.

	      [EFBIG] or [EINVAL]    The length argument was greater than  the
				     maximum file size.

	      An  I/O  error  occurred while reading from or writing to a file
	      system.

	      Enforcement mode file/record locking is set (see
				     chmod(2)),	 and  there  are   outstanding
				     record locks on the file with the or sys‐
				     tem calls.

       If fails, is set to one of the following values:

	      [EBADF] or [EINVAL]    The  fildes  argument  is	not   a	  file
				     descriptor open for writing.

	      The user's disk quota block limit has been reached for this file
	      system.

	      The		     fildes argument references	 a  file  that
				     was opened without write permission.

       If fails, is set to one of the following values:

	      A component of the     path  prefix denies search permission, or
				     write permission is denied on the file.

	      The user's disk quota block limit has been reached for this file
	      system.

	      path		     points  outside  the  process's allocated
				     address space. The reliable detection  of
				     this error is implementation dependent.

	      The named file is a directory.

	      Too many symbolic links were encountered in resolving
				     path.

	      Pathname resolution produced an intermediate result
				     whose length exceeds bytes, or the length
				     of a component of	the  pathname  exceeds
				     bytes.

	      A component of	     does not name an existing file or path is
				     an empty string.

	      A component of the     path prefix of path is not a directory.

	      The named file resides on a read-only file system.

	      The file is a pure procedure (shared text) file  that  is	 being
	      executed.

AUTHOR
       was developed by the University of California, Berkeley.

SEE ALSO
       chmod(2),  fcntl(2), flock(2), ftruncate64(2), lockf(2), open(2), trun‐
       cate64(2), privileges(5), <unistd.h>.

CHANGE HISTORY
       First released in Issue 4, Version 2.

STANDARDS CONFORMANCE
       truncate(): AES ftruncate(): AES, SVID3

								   truncate(2)

Vote for polarhome