We've been showing you how to use
in the Command function.
You can also execute an
Action returned by a factory
(or actually, any
at the time the SConscript file is read
by wrapping it up in the Execute function.
For example, if we need to make sure that
a directory exists before we build any targets,
Notice that this will create the directory while the SConscript file is being read:
% scons scons: Reading SConscript files ... Mkdir("/tmp/my_temp_directory") scons: done reading SConscript files. scons: Building targets ... scons: `.' is up to date. scons: done building targets.
If you're familiar with Python, you may wonder why you would want to use this instead of just calling the native Python os.mkdir() function. The advantage here is that the Mkdir action will behave appropriately if the user specifies the SCons -n or -q options--that is, it will print the action but not actually make the directory when -n is specified, or make the directory but not print the action when -q is specified.