truncate(2)                                           truncate(2)



     NAME
          truncate - truncate a file to a specified length

     SYNOPSIS
          truncate(path, length)
          char *path;
          int length;

          ftruncate(fd, length)
          int fd, length;

     DESCRIPTION
          truncate causes the file named by path or referenced by fd
          to be truncated to at most length bytes in size.  If the
          file previously was larger than this size, the extra data is
          lost.  With ftruncate, the file must be open for writing.

     RETURN VALUES
          A value of 0 is returned if the call succeeds.  If the call
          fails a -1 is returned, and the global variable errno
          specifies the error.

     ERRORS
          truncate succeeds unless:

          [EPERM]        The pathname contains a character with the
                         high-order bit set.

          [ENOENT]       The pathname was too long.

          [ENOTDIR]      A component of the path prefix of path is not
                         a directory.

          [ENOENT]       The named file does not exist.

          [EACCES]       A component of the path prefix denies search
                         permission.

          [EISDIR]       The named file is a directory.

          [EROFS]        The named file resides on a read-only file
                         system.

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

                         Note: If you are running an NFS system and
                         you are accessing a shared binary remotely,
                         it is possible that you will not get this
                         errno.

          [EFAULT]       name points outside the process's allocated



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     truncate(2)                                           truncate(2)



                         address space.

          ftruncate succeeds unless:

          [EBADF]        The fd is not a valid descriptor.

          [EINVAL]       The fd references a socket, not a file.

     SEE ALSO
          open(2).

     BUGS
          Partial blocks discarded as the result of truncation are not
          zero filled; this can result in holes in files which do not
          read as zero.

          These calls should be generalized to allow ranges of bytes
          in a file to be discarded.





































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