Question

I have a batch the would display usage if your parameter is invalid.

For ex.

   Running "sample.bat update fuh"

   :usageactions
   set actions=%*
   set toremove=update
   set todisplay=%actions:%toremove% =%
   echo Error: Invalid Arguments - '%todisplay%'.
   echo Type sample.bat %toremove% -h for usage.

Expected Output:

  Error: Invalid Arguments - 'fuh'.
  Type sample.bat update -h for usage

But my output is:

  Error: Invalid Arguments - 'update'.
  Type sample.bat update -h for usage

How to achived it? Any help would be appreciated. Thanks.

(By the way, please modify the question if its so confusing.)

Answer 1

You try to expand an expression more than once in a line, but the parser can’t guess which percents are pairs.

set todisplay=%actions:%toremove% =%

You could use here delayed expansion

setlocal EnableDelayedExpansion
set toDisplay=!actions:%toRemove% =!

First %toRemove% will be expanded and then the line looks like

set toDisplay=!actions:update =!

and then the exclamation expression will be evaluated.