Daily Archives: April 13, 2011

In Words of One Syllable

The Windows CMD shell is a primitive language, particularly when compared to unix scripts or even PowerShell.  But it’s still the only guaranteed-available common denominator for Windows servers (no, WSH doesn’t count), so I have to target it for setup scripts delivered to customers.  When it comes to database activities, I limit this as much as possible by writing portable DB2 CLP SQL files, but that runs out of steam when I need loops, parameters, etc.  So I found myself this morning once again bumping up against CMD’s limited vocabulary.

In this case, I needed a multi-line block of SQLs to run in a loop.  The begin-end construct for CMD scripts is a pair of parentheses.  But my SQLs themselves needed parentheses (as SQLs often do), and I found that Windows doesn’t support nesting them; it failed with a the error message: <statement> was unexpected at this time.  No nested parens: just wow.  At least the workaround was simple – just move these commands into a sub-script and call it, like so:

   for /l %%i in (1,1,9) do (
      echo.  ==Pass %%i >> %OutputFilename%
      call ReplicatePass.cmd %%i >>%OutputFilename%
      if errorlevel 1 goto failure

I look forward to the day when I can count on PowerShell or a similar robust scripting environment to be available on all Windows platforms I target.  Perhaps attrition alone will accomplish this; after all, it has only taken three decades.  Until then, I’ll speak slowly to Windows, in words of one syllable.