# $Id$ """ Introduction ============ ``fortune`` is a stripped-down implementation of the classic BSD Unix ``fortune`` command. It combines the capabilities of the ``strfile`` command (which produces the fortune index file) and the ``fortune`` command (which displays a random fortune). It reads the traditional ``fortune`` program's text file format. Usage ===== Usage:: fortune [OPTIONS] /path/to/fortunes OPTIONS -h, --help Show usage and exit. -u, --update Update the index file. -q, --quiet When updating the index file, do so quietly. -V, --version Show version and exit. If you omit the path, ``fortune`` looks at the ``FORTUNE_FILE`` environment variable. If that environment variable isn't set, ``fortune`` aborts. Fortune Cookie File Format ========================== A fortune cookie file is a text file full of quotes. The format is simple: The file consists of paragraphs separated by lines containing a single '%' character. For example:: A little caution outflanks a large cavalry. -- Bismarck % A little retrospection shows that although many fine, useful software systems have been designed by committees and built as part of multipart projects, those software systems that have excited passionate fans are those that are the products of one or a few designing minds, great designers. Consider Unix, APL, Pascal, Modula, the Smalltalk interface, even Fortran; and contrast them with Cobol, PL/I, Algol, MVS/370, and MS-DOS. -- Fred Brooks, Jr. % A man is not old until regrets take the place of dreams. -- John Barrymore The Index File ============== For efficiency and speed, ``fortune`` uses an index file to store the offsets and lengths of every fortune in the text fortune file. So, before you can use ``fortune`` to read a random fortune, you have to generate the data file. With the traditional BSD ``fortune`` program, you used the I{strfile}(8) command to generate the index. With I{this} fortune program, however, you simply pass a special argument to the ``fortune`` command:: fortune -u /path/to/fortunes That command will generate a binary ``/path/to/fortunes.dat`` file that contains the index. You should run ``fortune -u`` whenever you change the text fortune file. Generating a Random Fortune =========================== Once you have an index file, you can generate a random fortune simply by running the ``fortune`` utility with the path to your text fortunes file:: fortune /path/to/fortunes Differences =========== This version of ``fortune`` does not provide some of the more advanced capabilities of the original BSD program. For instance, it lacks: - the ability to mark offensive and inoffensive fortunes - the ability to separate long and short quotes - the ability to print all fortunes matching a regular expression It does, however, provide the most important function: The ability to display a random quote from a set of quotes. License and Copyright Info ========================== Copyright (c) 2008 Brian M. Clapper This is free software, released under the following BSD-like license: Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. - The end-user documentation included with the redistribution, if any, must include the following acknowlegement: This product includes software developed by Brian M. Clapper (bmc@clapper.org, http://www.clapper.org/bmc/). That software is copyright (c) 2008 Brian M. Clapper. Alternately, this acknowlegement may appear in the software itself, if and wherever such third-party acknowlegements normally appear. THIS SOFTWARE IS PROVIDED B{AS IS} AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BRIAN M. CLAPPER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. """ # --------------------------------------------------------------------------- # Imports # --------------------------------------------------------------------------- import random import os import sys import cPickle as pickle from grizzled.cmdline import CommandLineParser # --------------------------------------------------------------------------- # Exports # --------------------------------------------------------------------------- __all__ = ['main', 'get_random_fortune', 'make_fortune_data_file'] # Info about the module __version__ = '0.5' __author__ = 'Brian M. Clapper' __email__ = 'bmc@clapper.org' __url__ = 'http://www.clapper.org/software/python/fortune/' __copyright__ = '2008-2009 Brian M. Clapper' __license__ = 'BSD-style license' # --------------------------------------------------------------------------- # Internal Constants # --------------------------------------------------------------------------- _PICKLE_PROTOCOL = 2 # --------------------------------------------------------------------------- # Functions # --------------------------------------------------------------------------- def get_random_fortune(fortune_file): """ Get a random fortune from the specified file. Barfs if the corresponding ``.dat`` file isn't present. :Parameters: fortune_file : str path to file containing fortune cookies :rtype: str :return: the random fortune """ fortune_index_file = fortune_file + '.dat' if not os.path.exists(fortune_index_file): raise ValueError, 'Can\'t find file "%s"' % fortune_index_file fortuneIndex = open(fortune_index_file) data = pickle.load(fortuneIndex) fortuneIndex.close() randomRecord = random.randint(0, len(data) - 1) (start, length) = data[randomRecord] f = open(fortune_file, 'rU') f.seek(start) fortuneCookie = f.read(length) f.close() return fortuneCookie def _read_fortunes(fortune_file): """ Yield fortunes as lists of lines """ result = [] start = None pos = 0 for line in fortune_file: if line == "%\n": if pos == 0: # "%" at top of file. Skip it. continue yield (start, pos - start, result) result = [] start = None else: if start == None: start = pos result.append(line) pos += len(line) if result: yield (start, pos - start, result) def make_fortune_data_file(fortune_file, quiet=False): """ Create or update the data file for a fortune cookie file. :Parameters: fortune_file : str path to file containing fortune cookies quiet : bool If ``True``, don't display progress messages """ fortune_index_file = fortune_file + '.dat' if not quiet: print 'Updating "%s" from "%s"...' % (fortune_index_file, fortune_file) data = [] shortest = sys.maxint longest = 0 for start, length, fortune in _read_fortunes(open(fortune_file, 'rU')): data += [(start, length)] shortest = min(shortest, length) longest = max(longest, length) fortuneIndex = open(fortune_index_file, 'wb') pickle.dump(data, fortuneIndex, _PICKLE_PROTOCOL) fortuneIndex.close() if not quiet: print 'Processed %d fortunes.\nLongest: %d\nShortest %d' %\ (len(data), longest, shortest) def main(): """ Main program. """ usage = 'Usage: %s [OPTIONS] fortune_file' % os.path.basename(sys.argv[0]) arg_parser = CommandLineParser(usage=usage) arg_parser.add_option('-q', '--quiet', action='store_true', dest='quiet', help="When updating the index file, don't emit " \ "messages.") arg_parser.add_option('-u', '--update', action='store_true', dest='update', help='Update the index file, instead of printing a ' 'fortune.') arg_parser.add_option('-V', '--version', action='store_true', dest='show_version', help='Show version and exit.') arg_parser.epilogue = 'If is omitted, fortune looks at the ' \ 'FORTUNE_FILE environment variable for the path.' options, args = arg_parser.parse_args(sys.argv) if len(args) == 2: fortune_file = args[1] else: try: fortune_file = os.environ['FORTUNE_FILE'] except KeyError: arg_parser.show_usage('Missing fortune file.') try: if options.show_version: print 'fortune, version %s' % __version__ elif options.update: make_fortune_data_file(fortune_file) else: sys.stdout.write(get_random_fortune(fortune_file)) except ValueError, msg: print >> sys.stderr, msg sys.exit(1) if __name__ == '__main__': main()