idlastro / Database Procedures: DBXVAL

[Source code]

NAME
DBXVAL
PURPOSE
Quickly return a value of the specified item number     
EXPLANATION
Procedure to quickly return a value of the specified item number
from the entry.
CALLING SEQUENCE
result = dbxval( entry, idltype, nvalues, sbyte, nbytes )
INPUTS
entry - entry or entries from data base (bytarr) 
idltype - idl data type (obtained with db_item_info)
nvalues - number of values to return (obtained with db_item)
sbyte - starting byte in the entry (obtained with db_item)
nbytes - number of bytes (needed only for string type)
                (obtained with db_item)
OUTPUTS
function value is value of the specified item in entry
KEYWORDS
bswap - If set, then SWAP_ENDIAN_INPLACE is called.
RESTRICTIONS
To increase speed the routine assumes that entry and item are
valid and that the data base is already opened using dbopen.
REVISION HISTORY
version 0  D. Lindler Nov. 1987  (for new db format)
Version 1, William Thompson, GSFC, 28 March 1994.
                Incorporated into CDS library.
Version 2, Richard Schwartz, GSFC/SDAC, 23 August 1996
                Allowed Entry to have 2 dimensions
Version 2.1, 22 Feb 1997, JK Feggans, 
                        avoid reform for strings arrays.
Version 2.2     Use overwrite with REFORM(),  W. Landsman,  May 1997
Work for multiple-valued strings   W. Landsman   October 2000
Add new 64bit & unsigned integer datatypes W.Landsman   July 2001
Version 3, 2-May-2003, JK Feggans/Sigma, W.T. Thompson
    Added BSWAP keyword to avoid floating errors on some platforms.
Version 3.1 Remove IEEE_TO_HOST  W. Landsman   May 2016