st: Checking if a file is svyset

[Richard Williams <Richard.A.Williams.5@ND.edu>]

What is the best way for a program to check if a file is 
svyset?  Further, is it possible to check whether a file was svyset 
under version 9 (when the format changed) as opposed to an earlier version?

Right now my program has code like this:

                quietly version `c(stata_version)': svyset
                if "`r(settings)'" == ", clear(all)" {
                        display as error "svy option requires the 
data to be svyset"
                        exit 198
                }
This checks whether the file is svyset.  If the file is svyset under 
Stata 9 and you are running Stata 8.2, you get the error message.

Later on I have

                quietly version 8.2: svyset
                if "`r(settings)'" == ", clear(all)" local svy9 "svy9"

If you are running Stata 9, this will tell you that the file was 
svyset under Stata 9 (because 9.0+ could tell that it was svyset but 
8.2 cannot.)

This seems a little clunky though, and depends on the value of 
r(settings), and I am not sure you can count on that forever being the same.

-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
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