SCons has built-in facilities to save variables to a file and load them back - especially useful to store information like installation prefix (if you want to make an uninstall target, for instance), or the results of a configure step.
First create a Variables object
1 # specify the name of the file in which variables are/will be stored
2 vars = Variables('build-setup.conf')
3
4 # Register which variables we're interested in and
5 # get values from a saved file if any (defaults, which are
6 # specified in the last argument, are used otherwise)
7 vars.Add('config', '', 'release')
8 vars.Add('prefix', '', '/usr/local')
9 vars.Add('platform', '', 'auto')
10 vars.Add('glut_enabled', '', False)
11 vars.Add('havegettext', '', '')
12
13 # update these variables in your environment
14 vars.Update(env)
15
16 # do your stuff with the variables
17
18 if env['config'] == "debug":
19 env.Append(CCFLAGS=['-g','-Wfatal-errors'])
20 elif env['config'] == "release":
21 env.Append(CCFLAGS=['-O3','-DNDEBUG'])
22
23 # change variables if needed (e.g. if you're running a
24 #'configure' step, or if environment changed)
25 if changing_values:
26 env['platform'] = "unix"
27 # save new values
28 vars.Save('build-setup.conf', env)