% @(#)read_desc.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:51 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      read_desc.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, READ/DESCR
%.PURPOSE    On-line help file for the command: READ/DESCR
%.VERSION    1.0  13-APR-1984 : Creation, KB
%----------------------------------------------------------------
\se
SECTION./DESC
\es\co
READ/DESCR					25-JUL-2000  KB
\oc\su
READ/DESCR name [descr_list] [disp_flag]
	display descriptor values of frame or table 
\us\pu
Purpose: 
           Display descriptor values of Midas image or table
           or FITS header of FITS file.
\up\sb
Subject:
           Descriptors, Data frames, Tables
\bs\sy
Syntax: 
           READ/DESCR name [descr_list] [disp_flag]
\ys\pa
           name = name of data frame holding descriptor;
              default file type is .bdf; so if you want to see the descriptors
              of a table, you have to append also the type (e.g.: `.tbl')
              to the filename
\ap\pa
           descr_list = descriptor name(s) or pattern(s) separated by a comma,
\\
              or `*' to display all descriptors,
\\
              or patternA|patternB (character `|' as used for OR in C or the 
              pipe symbol in Unix) to display all descriptors with names
              matching patternA but not patternB,
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              or 'name.ascii' if ASCII file `name.ascii' contains the 
              descriptors to be read (file type .ascii is required); 
\\
              defaulted to the list of standard descriptors of images or tables
\ap\pa
           disp_flag = B(rief) or F(ull) or H(ide Header Info);
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              B: show only desriptor name(s) and value(s)
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              F: show also descriptor type and no. of elements as well as
                 related help text if available;
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              H: show only desriptor value(s)
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              defaulted to B
\ap\sa
See also:
           WRITE/DESCR, SHOW/DESCR, PRINT/DESCR, DELETE/DESCR, COPY/DD
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           WRITE/DHELP
\as\no
Note:    
           For patterns there are the following possibilities:
\\
              `abc*' => all descr. beginning with `abc' match
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              `*abc' => all descr. ending with `abc' match
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              `*abc*' => all descr. containing `abc' match
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              `abc*def' => all descr. beginning with `abc' and ending 
              with `def' match the pattern.
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           If all descriptors of the frame are displayed (descr_list = '*')
              you can also exclude (up to 4) descriptors which should NOT be
              displayed, by adding their names separated by a comma, or a
              single pattern (see above) defining them.
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           If descr_list is set to a specific descr. name, also the first
              4(5) elements of integer keyword OUTPUTI are filled:
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              OUTPUTI(1) = 1 or 0, if specified descr. exists or not.
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              If OUTPUTI(1) is 1, then (2) = descr. type (1,2,3 or 4 for
              integer, real, character or double descr);
              (3) and (4) hold no. of elements and bytes per element of 
              descr.
              And if `disp_flag' was set to Full, OUTPUTI(5) contains the
              size of the help text of the descriptor (-1, if no help).
              This information can then be used in a procedure.
           For a description of the standard descriptors of an image or
              a table, see the MIDAS Environment document, Appendix C.
\on\exs
Examples:
\ex
           READ/DESCR durazno STEP  
             Display contents of descriptor STEP of frame `durazno.bdf'.
\xe\ex
           READ/DESCR durazno start,step full
             Display descriptors STEP and START of frame `durazno.bdf' in
             extended format. Also, display the corresponding help text if
             available.
\xe\ex
           READ/DESCR naranja.tbl *
             Display all descriptors of table file `naranja.tbl'.
\xe\ex
           READ/DESCR fresa *,histogram,hist_bins
             Display all descriptors of image `fresa.bdf' except the two
             descriptors HISTOGRAM and HIST_BINS.
\xe\ex
           READ/DESCR fresa *,histo*
             Display all descriptors of image `fresa.bdf' except all
             descriptors beginning with HISTO (so also HISTORY would not be
             displayed).
\xe\ex
           READ/DESCR manzana naxis,*det*
             Display descr. NAXIS and all descriptors of frame `manzana.bdf' 
             with names containing `DET', e.g. ESO.DET.CHIP1.PSZX.
\xe\ex
           READ/DESCR pera ESO.*|*.det.*
             Display all hierarchical ESO keywords of `pera.bdf' except those 
             containing `DET', e.g. ESO.DET.CHIP1.PSZX would not be shown.
\xe\ex
           READ/DESCR platano papaya.ascii
             Display all descriptors which are in the ASCII file `papaya.ascii'
             E.g. if `papaya.ascii' contains the two records:
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             naxis,npix,start,step
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             history
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             the descriptors NAXIS, NPIX, START, STEP and HISTORY of frame
             `platano.bdf' would be displayed.
\xe \sxe