%scons; %builders-mod; %functions-mod; %tools-mod; %variables-mod; ]> Creating a &Builder; and attaching it to a &consenv; allows for a lot of flexibility when you want to re-use actions to build multiple files of the same type. This can, however, be cumbersome if you only need to execute one specific command to build a single file (or group of files). For these situations, &SCons; supports a &Command; &Builder; that arranges for a specific action to be executed to build a specific file or files. This looks a lot like the other builders (like &b-link-Program;, &b-link-Object;, etc.), but takes as an additional argument the command to be executed to build the file: env = Environment() env.Command('foo.out', 'foo.in', "sed 's/x/y/' < $SOURCE > $TARGET") foo.in When executed, &SCons; runs the specified command, substituting &cv-link-SOURCE; and &cv-link-TARGET; as expected: scons -Q This is often more convenient than creating a &Builder; object and adding it to the &cv-link-BUILDERS; variable of a &consenv; Note that the action you specify to the &Command; &Builder; can be any legal &SCons; &Action;, such as a Python function: env = Environment() def build(target, source, env): # Whatever it takes to build return None env.Command('foo.out', 'foo.in', build) foo.in Which executes as follows: scons -Q Note that &cv-link-SOURCE; and &cv-link-TARGET; are expanded in the source and target as well as of SCons 1.1, so you can write: env.Command('${SOURCE.basename}.out', 'foo.in', build) which does the same thing as the previous example, but allows you to avoid repeating yourself.