% @(#)deletedesc.hlq	13.1.1.1 (ESO-IPG) 06/02/98 18:14:38 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      deletedesc.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, DELETE/DESCRIPTOR
%.PURPOSE    On-line help file for the command: DELETE/DESCRIPTOR
%.VERSION    1.0  12-OCT-1983 : Creation, KB
%.VERSION    1.1  24-OCT-1991 : Modifcation, KB
%----------------------------------------------------------------
\se
SECTION./DESC
\es\co
DELETE/DESCRIPTOR					16-JAN-1999  KB
\oc\su
DELETE/DESCRIPTOR frame descr_list [stop_flag]
	delete descriptors of frame
\us\pu
Purpose: 
           Delete descriptors of frame.
\up\sy
Syntax: 
           DELETE/DESCR frame descr_list [stop_flag]
\ys\pa
           frame = name of frame
\ap\pa
           descr_list = descriptor name(s) or pattern(s) separated by a comma,
\\
                or `*' to delete all descriptors,
\ap\pa
           stop_flag = optional stop flag, = Yes or No, if any descriptor
                name specified in `descr_list' could not be found;
\\
                however, this applies only to fully specified descriptor 
                names in `descr_list', not patterns because for these we 
                don't know beforehand which names will match the pattern;
\\
                defaulted to Yes
\ap\sa
See also:
           WRITE/DESCR, READ/DESCR, PRINT/DESCR, SHOW/DESCR, COPY/DD
\as\no
Note:  
           Deleting a descriptor only removes its entry in the descriptor
           directory of a frame, the space used up for data will not be
           reused later. Therefore, adding and deleting descriptors all the
           time is not such a good idea because the frame keeps on growing...
\\
           The only way to really reclaim the data space of deleted descriptors
           is to copy the frame to another one (e.g. via the COPY/II command)
           and then renaming the output frame back to the original one.
\\
           The application procedure `packdsc.prg' will do that for you, see
           HELP/APPLIC packdsc for details.
\\
           The syntax for patterns in `descr_list' is as follows:
\\
           `abc*' => all descr. beginning with `abc' match
\\
           `*abc' => all descr. ending with `abc' match
\\
           `*abc*' => all descr. containing `abc' match
\\
           `abc*def' => all descr. beginning with `abc' and ending with `def'
           match the pattern.
\\
           If `stop_flag' = Yes, the command stops with an error if any of
           the descriptors (with fully specified name) to be deleted does not
           exist.
\\
           Unless you delete all descriptors (descr_list = `*'), the no. of
           actually deleted descriptors is stored in keyword OUTPUTI(1).
\on\exs
Examples:
\ex
           DELETE/DESCR caballo instrume
             Remove descriptor INSTRUME from frame `caballo.bdf'.
\xe \ex
           DELETE/DESCR caballo lola,instrume no
             Try to delete descr. LOLA and INSTRUME. If any of the two descrs.
             does not exist, the command does not stop with an error and a
             procedure with this command would continue.
\xe \ex
           DELETE/DESCR asno *
             Remove all descriptors from frame `asno.bdf' - not really
             recommended...
\xe \ex
           DELETE/DESCR burro cunit,*.det.*,o_pos
             Remove the descriptor CUNIT, all descriptors containing the
             string .DET. (e.g. ESO.DET.CHIPS) and descr O_POS from frame 
             `burro.bdf'.
\\
             If descriptor CUNIT does not exist in frame `burro.bdf', the
             command stops before deleting any of the other descriptors.
\xe \sxe