Re: st: [Stata 12] Issue with -export excel-

[Alan Riley <ariley@stata.com>]

Eric Booth (ebooth@ppri.tamu.edu) asked some questions about Stata 12.

Eric's first question was about an error he received after exporting a
dataset to .xlsx format with -export excel-.  He answered his own question
when he found that one of his string variables contained a binary character
in one of its values.  Excel cannot read a .xlsx file which contains
a binary character in a string value.  Printable extended ASCII characters
are supported.

Eric's third question regarding shifting blocks of code in the
Do-file Editor in Stata for Mac was answered here:

   http://www.stata.com/statalist/archive/2011-07/msg00963.html

Eric's second question involved an error he received when using
an -if- statement without curly braces { } to indicate the code
that should be executed when the -if- condition is true.  In
addition, the code he wanted to execute used an '!' to shell
out to the operating system.

When Eric coded

   foreach file in input dta {
      if "`c(os)'" == "MacOSX" {
         !open "from`file'.xlsx"
      }
   }

his code worked as expected.  But, when he coded
	
   foreach file in input dta {
      if "`c(os)'" == "MacOSX"  !open "from`file'.xlsx"
   }

he received an error.  Eric thought this error was new to Stata 12
and that Stata 11 ran such code fine.

Both Stata 11 and Stata 12 can execute code that looks like

   if some_expression  do_this_if_some_expression_is_true

And, both Stata 11 and Stata 12 can execute code that looks like

   if some_expression {
      do_this_if_some_expression_is_true
   }

However, if the single-line case, if the code to be executed when the
expression is true begins with an exclamation point (!) to shell out to
the operating system, both Stata 11 and Stata 12 will error out:

   if some_expression  !do_this_by_shelling_out

Stata's expression parser is interpreting the '!' as part of
the expression even though it doesn't affect evaluation of the
expression.  Thus, when shelling out to the operating system
in an -if- condition, Eric should always code

   if some_expression {
      !do_this_by_shelling_out
   }


--
Alan
ariley@stata.com

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