9/29/88   write_data_file,  wdf

Syntax:  write_data_file pathname {-control_args}


Function:  retrieves the selected data and places it in an output file
in a format suitable for input to the store_from_data_file request.


Arguments:

pathname
   is the name of the file where the data will be written to.


Control arguments:

-column_delimiter X, -cdm X
   where X is a single ascii character which will be used to delimit
   the column values.  If this control argument isn't specified the
   default column delimiter is the tilde.

-create_columns STRING, -crc STRING
   new columns with null values are placed in the column positions
   specified by STRING.  STRING is a blank separated list of numbers.
   (See "Notes" below.)

-extend
   specifies that if the file already exists it should be extended
   rather than truncated.


-no_progress, -npg
   specifies that progress messages should not be printed. (DEFAULT)

-progress {N}, -pg {N}
   specifies that a progress message should be printed after N tuples
   have been processed, where N is any positive integer. If N is not
   specified the default is to print a progress message after 1000
   tuples.

-row_delimiter X, -rdm X
   where X is a single ascii character which will be used to delimit
   the row values.  If this control argument isn't specified the
   default row delimiter is the newline character.


-truncate
   specifies that if the file already exists it should be truncated.
   This is the default.


Notes:

The -create_columns control argument is provided to aid in the
restructuring of tables.  The column positions specified are the
positions in the output file where the null value will be placed.  To
create two new columns as the third and fifth columns in the output
file the string "-create_columns 3 5" would be used.  The null value is
provided by placing two column delimiters together without any
intervening characters, and the zero length character string is
converted according to the data type of the column when the
store_from_data_file request processes the input file.


Column values are examined to determine if they contain quotes, column
delimiters, or row delimiters.  If any of these are found the column
value is requoted before it is placed in the output file.  The
store_from_data_file request removes this layer of quotes when
processing the file.


Examples:

write_data_file employee_data
write_data_file employee_data -extend
write_data_file employee_data -create_columns 1 5
write_data_file employee_data -column_delimiter X


                                          -----------------------------------------------------------


Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

                                          -----------------------------------------------------------

Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved