"""distutils.cmd Provides the Command class, the base class for the command classes in the distutils.command package.""" # created 2000/04/03, Greg Ward # (extricated from core.py; actually dates back to the beginning) __revision__ = "$Id$" import sys, string from types import * from distutils.errors import * from distutils import util class Command: """Abstract base class for defining command classes, the "worker bees" of the Distutils. A useful analogy for command classes is to think of them as subroutines with local variables called "options". The options are "declared" in 'initialize_options()' and "defined" (given their final values, aka "finalized") in 'finalize_options()', both of which must be defined by every command class. The distinction between the two is necessary because option values might come from the outside world (command line, option file, ...), and any options dependent on other options must be computed *after* these outside influences have been processed -- hence 'finalize_options()'. The "body" of the subroutine, where it does all its work based on the values of its options, is the 'run()' method, which must also be implemented by every command class.""" # -- Creation/initialization methods ------------------------------- def __init__ (self, dist): """Create and initialize a new Command object. Most importantly, invokes the 'initialize_options()' method, which is the real initializer and depends on the actual command being instantiated.""" # late import because of mutual dependence between these classes from distutils.dist import Distribution if not isinstance (dist, Distribution): raise TypeError, "dist must be a Distribution instance" if self.__class__ is Command: raise RuntimeError, "Command is an abstract class" self.distribution = dist self.initialize_options () # Per-command versions of the global flags, so that the user can # customize Distutils' behaviour command-by-command and let some # commands fallback on the Distribution's behaviour. None means # "not defined, check self.distribution's copy", while 0 or 1 mean # false and true (duh). Note that this means figuring out the real # value of each flag is a touch complicatd -- hence "self.verbose" # (etc.) will be handled by __getattr__, below. self._verbose = None self._dry_run = None self._force = None # The 'help' flag is just used for command-line parsing, so # none of that complicated bureaucracy is needed. self.help = 0 # 'ready' records whether or not 'finalize_options()' has been # called. 'finalize_options()' itself should not pay attention to # this flag: it is the business of 'ensure_ready()', which always # calls 'finalize_options()', to respect/update it. self.ready = 0 # __init__ () def __getattr__ (self, attr): if attr in ('verbose', 'dry_run', 'force'): myval = getattr (self, "_" + attr) if myval is None: return getattr (self.distribution, attr) else: return myval else: raise AttributeError, attr def ensure_ready (self): if not self.ready: self.finalize_options () self.ready = 1 # Subclasses must define: # initialize_options() # provide default values for all options; may be overridden # by Distutils client, by command-line options, or by options # from option file # finalize_options() # decide on the final values for all options; this is called # after all possible intervention from the outside world # (command-line, option file, etc.) has been processed # run() # run the command: do whatever it is we're here to do, # controlled by the command's various option values def initialize_options (self): """Set default values for all the options that this command supports. Note that these defaults may be overridden by the command-line supplied by the user; thus, this is not the place to code dependencies between options; generally, 'initialize_options()' implementations are just a bunch of "self.foo = None" assignments. This method must be implemented by all command classes.""" raise RuntimeError, \ "abstract method -- subclass %s must override" % self.__class__ def finalize_options (self): """Set final values for all the options that this command supports. This is always called as late as possible, ie. after any option assignments from the command-line or from other commands have been done. Thus, this is the place to to code option dependencies: if 'foo' depends on 'bar', then it is safe to set 'foo' from 'bar' as long as 'foo' still has the same value it was assigned in 'initialize_options()'. This method must be implemented by all command classes.""" raise RuntimeError, \ "abstract method -- subclass %s must override" % self.__class__ def run (self): """A command's raison d'etre: carry out the action it exists to perform, controlled by the options initialized in 'initialize_options()', customized by the user and other commands, and finalized in 'finalize_options()'. All terminal output and filesystem interaction should be done by 'run()'. This method must be implemented by all command classes.""" raise RuntimeError, \ "abstract method -- subclass %s must override" % self.__class__ def announce (self, msg, level=1): """If the Distribution instance to which this command belongs has a verbosity level of greater than or equal to 'level' print 'msg' to stdout.""" if self.verbose >= level: print msg # -- Option query/set methods -------------------------------------- def get_option (self, option): """Return the value of a single option for this command. Raise DistutilsOptionError if 'option' is not known.""" try: return getattr (self, option) except AttributeError: raise DistutilsOptionError, \ "command %s: no such option %s" % \ (self.get_command_name(), option) def get_options (self, *options): """Return (as a tuple) the values of several options for this command. Raise DistutilsOptionError if any of the options in 'options' are not known.""" values = [] try: for opt in options: values.append (getattr (self, opt)) except AttributeError, name: raise DistutilsOptionError, \ "command %s: no such option %s" % \ (self.get_command_name(), name) return tuple (values) def set_option (self, option, value): """Set the value of a single option for this command. Raise DistutilsOptionError if 'option' is not known.""" if not hasattr (self, option): raise DistutilsOptionError, \ "command '%s': no such option '%s'" % \ (self.get_command_name(), option) if value is not None: setattr (self, option, value) def set_options (self, **optval): """Set the values of several options for this command. Raise DistutilsOptionError if any of the options specified as keyword arguments are not known.""" for k in optval.keys(): if optval[k] is not None: self.set_option (k, optval[k]) # -- Convenience methods for commands ------------------------------ def get_command_name (self): if hasattr (self, 'command_name'): return self.command_name else: return self.__class__.__name__ def set_undefined_options (self, src_cmd, *option_pairs): """Set the values of any "undefined" options from corresponding option values in some other command object. "Undefined" here means "is None", which is the convention used to indicate that an option has not been changed between 'set_initial_values()' and 'set_final_values()'. Usually called from 'set_final_values()' for options that depend on some other command rather than another option of the same command. 'src_cmd' is the other command from which option values will be taken (a command object will be created for it if necessary); the remaining arguments are '(src_option,dst_option)' tuples which mean "take the value of 'src_option' in the 'src_cmd' command object, and copy it to 'dst_option' in the current command object".""" # Option_pairs: list of (src_option, dst_option) tuples src_cmd_obj = self.distribution.find_command_obj (src_cmd) src_cmd_obj.ensure_ready () try: for (src_option, dst_option) in option_pairs: if getattr (self, dst_option) is None: self.set_option (dst_option, src_cmd_obj.get_option (src_option)) except AttributeError, name: # duh, which command? raise DistutilsOptionError, "unknown option %s" % name def find_peer (self, command, create=1): """Wrapper around Distribution's 'find_command_obj()' method: find (create if necessary and 'create' is true) the command object for 'command'..""" cmd_obj = self.distribution.find_command_obj (command, create) cmd_obj.ensure_ready () return cmd_obj def get_peer_option (self, command, option): """Find or create the command object for 'command', and return its 'option' option.""" cmd_obj = self.find_peer (command) return cmd_obj.get_option (option) def run_peer (self, command): """Run some other command: uses the 'run_command()' method of Distribution, which creates the command object if necessary and then invokes its 'run()' method.""" self.distribution.run_command (command) # -- External world manipulation ----------------------------------- def warn (self, msg): sys.stderr.write ("warning: %s: %s\n" % (self.get_command_name(), msg)) def execute (self, func, args, msg=None, level=1): """Perform some action that affects the outside world (eg. by writing to the filesystem). Such actions are special because they should be disabled by the "dry run" flag, and should announce themselves if the current verbosity level is high enough. This method takes care of all that bureaucracy for you; all you have to do is supply the funtion to call and an argument tuple for it (to embody the "external action" being performed), a message to print if the verbosity level is high enough, and an optional verbosity threshold.""" # Generate a message if we weren't passed one if msg is None: msg = "%s %s" % (func.__name__, `args`) if msg[-2:] == ',)': # correct for singleton tuple msg = msg[0:-2] + ')' # Print it if verbosity level is high enough self.announce (msg, level) # And do it, as long as we're not in dry-run mode if not self.dry_run: apply (func, args) # execute() def mkpath (self, name, mode=0777): util.mkpath (name, mode, self.verbose, self.dry_run) def copy_file (self, infile, outfile, preserve_mode=1, preserve_times=1, link=None, level=1): """Copy a file respecting verbose, dry-run and force flags.""" return util.copy_file (infile, outfile, preserve_mode, preserve_times, not self.force, link, self.verbose >= level, self.dry_run) def copy_tree (self, infile, outfile, preserve_mode=1, preserve_times=1, preserve_symlinks=0, level=1): """Copy an entire directory tree respecting verbose, dry-run, and force flags.""" return util.copy_tree (infile, outfile, preserve_mode,preserve_times,preserve_symlinks, not self.force, self.verbose >= level, self.dry_run) def move_file (self, src, dst, level=1): """Move a file respecting verbose and dry-run flags.""" return util.move_file (src, dst, self.verbose >= level, self.dry_run) def spawn (self, cmd, search_path=1, level=1): from distutils.spawn import spawn spawn (cmd, search_path, self.verbose >= level, self.dry_run) def make_archive (self, base_name, format, root_dir=None, base_dir=None): util.make_archive (base_name, format, root_dir, base_dir, self.verbose, self.dry_run) def make_file (self, infiles, outfile, func, args, exec_msg=None, skip_msg=None, level=1): """Special case of 'execute()' for operations that process one or more input files and generate one output file. Works just like 'execute()', except the operation is skipped and a different message printed if 'outfile' already exists and is newer than all files listed in 'infiles'.""" if exec_msg is None: exec_msg = "generating %s from %s" % \ (outfile, string.join (infiles, ', ')) if skip_msg is None: skip_msg = "skipping %s (inputs unchanged)" % outfile # Allow 'infiles' to be a single string if type (infiles) is StringType: infiles = (infiles,) elif type (infiles) not in (ListType, TupleType): raise TypeError, \ "'infiles' must be a string, or a list or tuple of strings" # If 'outfile' must be regenerated (either because it doesn't # exist, is out-of-date, or the 'force' flag is true) then # perform the action that presumably regenerates it if self.force or util.newer_group (infiles, outfile): self.execute (func, args, exec_msg, level) # Otherwise, print the "skip" message else: self.announce (skip_msg, level) # make_file () # class Command