12.2. Deleting Files or Directories: The Delete Factory

If you need to delete a file, then the Delete factory can be used in much the same way as the Copy factory. For example, if we want to make sure that the temporary file in our last example doesn't exist before we copy to it, we could add Delete to the beginning of the command list:

      Command("file.out", "file.in",
              [
                Delete("tempfile"),
                Copy("tempfile", "$SOURCE"),
                "modify tempfile",
                Copy("$TARGET", "tempfile"),
              ])
    

When then executes as follows:

      % scons -Q
      Delete("tempfile")
      Copy("tempfile", "file.in")
      modify tempfile
      Copy("file.out", "tempfile")
    

Of course, like all of these Action factories, the Delete factory also expands $TARGET and $SOURCE variables appropriately. For example:

      Command("file.out", "file.in",
              [
                Delete("$TARGET"),
                Copy("$TARGET", "$SOURCE")
              ])
    

Executes as:

      % scons -Q
      Delete("file.out")
      Copy("file.out", "file.in")
    

(Note, however, that you typically don't need to call the Delete factory explicitly in this way; by default, SCons deletes its target(s) for you before executing any action.