idlastro / Database Procedures: DBHELP

[Source code]

NAME
DBHELP
PURPOSE
List available databases or items in the currently open database
EXPLANATION
Procedure to either list available databases (if no database is 
currently open) or the items in the currently open database.
CALLING SEQUENCE
dbhelp, [ flag , TEXTOUT=, /SORT ]
INPUT
flag - (optional) if set to nonzero then item or database
        descriptions are also printed
        default=0
        If flag is a string, then it is interpreted as the
        name of a data base (if no data base is opened) or a name 
        of an item in the opened data base.   In this case, help
        is displayed only for the particular item or database
OUTPUTS
None
OPTIONAL INPUT KEYWORDS
TEXTOUT  - Used to determine output device.  If not present, the
          value of !TEXTOUT system variable is used (see TEXTOPEN )
         textout=0       Nowhere
         textout=1       if a TTY then TERMINAL using /more option
                             otherwise standard (Unit=-1) output
         textout=2       if a TTY then TERMINAL without /more option
                             otherwise standard (Unit=-1) output
         textout=3       .prt
         textout=4       laser.tmp
         textout=5      user must open file
         textout=7      same as 3 but text is appended to .prt
                         file if it already exists.
         textout = filename (default extension of .prt)
  /SORT - If set and non-zero, then the help items will be displayed
         sorted alphabetically.    If more than one database is open,
         then this keyword does nothing.
METHOD
If no data base is opened then a list of data bases are
printed, otherwise the items in the open data base are printed.
If a string is supplied for flag and a data base is opened
flag is assumed to be an item name.  The information for that
item is printed along with contents in a optional file
zdbase:dbname_itemname.hlp
if a string is supplied for flag and no data base is opened,
then string is assumed to be the name of a data base file.
only information for that file is printed along with an
optional file zdbase:dbname.hlp.
PROCEDURES USED
DB_INFO(),DB_ITEM_INFO(),FIND_WITH_DEF(), TEXTOPEN, TEXTCLOSE, UNIQ()
IDL VERSION
V5.3 or later (uses vectorized FDECOMP)
HISTORY
Version 2  D. Lindler  Nov 1987 (new db format)
Faster printing of title desc. W. Landsman  May 1989 
Keyword textout added, J. Isensee, July, 1990
Modified to work on Unix, D. Neill, ACC, Feb 1991.
William Thompson, GSFC/CDS (ARC), 1 June 1994
        Added support for external (IEEE) representation.
William Thompson, GSFC, 3 November 1994
        Modified to allow ZDBASE to be a path string.
Remove duplicate database names  Wayne Landsman    December 1994
8/17/95 jkf/acc - force lowercase filenames for .hlp files.
Added /SORT keyword  J. Sandoval/W. Landsman     October 1998
V5.3 version use vectorized FDECOMP   W. Landsman   February 2001
Recognize 64 bit, unsigned integer datatypes W. Landsman September 2001
Fix display of number of bytes with /SORT W. Landsman February 2002
Assume since V5.2                 W. Landsman February 2002  
Assume since V5.5                 W. Landsman 
Define !TEXTOUT if not already defined W. Landsman  April 2016