add hg and python

23 files changed, 2021 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Demo/scripts/README b/sys/src/cmd/python/Demo/scripts/README
new file mode 100644
index 000000000..d8434e8d4
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/README
@@ -0,0 +1,23 @@
+This directory contains a collection of executable Python scripts.
+
+See also the Tools/scripts directory!
+
+beer.py			Print the classic 'bottles of beer' list.
+eqfix.py		Fix .py files to use the correct equality test operator
+fact.py			Factorize numbers
+find-uname.py		Search for Unicode characters using regexps.
+from.py			Summarize mailbox
+ftpstats.py		Summarize ftp daemon log file
+lpwatch.py		Watch BSD line printer queues
+makedir.py		Like mkdir -p
+markov.py		Markov chain simulation of words or characters
+mboxconvvert.py		Convert MH or MMDF mailboxes to unix mailbox format
+mkrcs.py		Fix symlinks named RCS into parallel tree
+morse.py		Produce morse code (audible or on AIFF file)
+pi.py			Print all digits of pi -- given enough time and memory
+pp.py			Emulate some Perl command line options
+primes.py		Print prime numbers
+queens.py		Dijkstra's solution to Wirth's "N Queens problem"
+script.py		Equivalent to BSD script(1) -- by Steen Lumholt
+unbirthday.py		Print unbirthday count
+update.py		Update a bunch of files according to a script.
diff --git a/sys/src/cmd/python/Demo/scripts/beer.py b/sys/src/cmd/python/Demo/scripts/beer.py
new file mode 100644
index 000000000..1b9ac8bad
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/beer.py
@@ -0,0 +1,14 @@
+#! /usr/bin/env python
+# By GvR, demystified after a version by Fredrik Lundh.
+import sys
+n = 100
+if sys.argv[1:]: n = int(sys.argv[1])
+def bottle(n):
+    if n == 0: return "no more bottles of beer"
+    if n == 1: return "one bottle of beer"
+    return str(n) + " bottles of beer"
+for i in range(n):
+    print bottle(n-i), "on the wall,"
+    print bottle(n-i) + "."
+    print "Take one down, pass it around,"
+    print bottle(n-i-1), "on the wall."
diff --git a/sys/src/cmd/python/Demo/scripts/eqfix.py b/sys/src/cmd/python/Demo/scripts/eqfix.py
new file mode 100755
index 000000000..35c43aa04
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/eqfix.py
@@ -0,0 +1,198 @@
+#! /usr/bin/env python
+
+# Fix Python source files to use the new equality test operator, i.e.,
+#       if x = y: ...
+# is changed to
+#       if x == y: ...
+# The script correctly tokenizes the Python program to reliably
+# distinguish between assignments and equality tests.
+#
+# Command line arguments are files or directories to be processed.
+# Directories are searched recursively for files whose name looks
+# like a python module.
+# Symbolic links are always ignored (except as explicit directory
+# arguments).  Of course, the original file is kept as a back-up
+# (with a "~" attached to its name).
+# It complains about binaries (files containing null bytes)
+# and about files that are ostensibly not Python files: if the first
+# line starts with '#!' and does not contain the string 'python'.
+#
+# Changes made are reported to stdout in a diff-like format.
+#
+# Undoubtedly you can do this using find and sed or perl, but this is
+# a nice example of Python code that recurses down a directory tree
+# and uses regular expressions.  Also note several subtleties like
+# preserving the file's mode and avoiding to even write a temp file
+# when no changes are needed for a file.
+#
+# NB: by changing only the function fixline() you can turn this
+# into a program for a different change to Python programs...
+
+import sys
+import re
+import os
+from stat import *
+import string
+
+err = sys.stderr.write
+dbg = err
+rep = sys.stdout.write
+
+def main():
+    bad = 0
+    if not sys.argv[1:]: # No arguments
+        err('usage: ' + sys.argv[0] + ' file-or-directory ...\n')
+        sys.exit(2)
+    for arg in sys.argv[1:]:
+        if os.path.isdir(arg):
+            if recursedown(arg): bad = 1
+        elif os.path.islink(arg):
+            err(arg + ': will not process symbolic links\n')
+            bad = 1
+        else:
+            if fix(arg): bad = 1
+    sys.exit(bad)
+
+ispythonprog = re.compile('^[a-zA-Z0-9_]+\.py$')
+def ispython(name):
+    return ispythonprog.match(name) >= 0
+
+def recursedown(dirname):
+    dbg('recursedown(%r)\n' % (dirname,))
+    bad = 0
+    try:
+        names = os.listdir(dirname)
+    except os.error, msg:
+        err('%s: cannot list directory: %r\n' % (dirname, msg))
+        return 1
+    names.sort()
+    subdirs = []
+    for name in names:
+        if name in (os.curdir, os.pardir): continue
+        fullname = os.path.join(dirname, name)
+        if os.path.islink(fullname): pass
+        elif os.path.isdir(fullname):
+            subdirs.append(fullname)
+        elif ispython(name):
+            if fix(fullname): bad = 1
+    for fullname in subdirs:
+        if recursedown(fullname): bad = 1
+    return bad
+
+def fix(filename):
+##      dbg('fix(%r)\n' % (dirname,))
+    try:
+        f = open(filename, 'r')
+    except IOError, msg:
+        err('%s: cannot open: %r\n' % (filename, msg))
+        return 1
+    head, tail = os.path.split(filename)
+    tempname = os.path.join(head, '@' + tail)
+    g = None
+    # If we find a match, we rewind the file and start over but
+    # now copy everything to a temp file.
+    lineno = 0
+    while 1:
+        line = f.readline()
+        if not line: break
+        lineno = lineno + 1
+        if g is None and '\0' in line:
+            # Check for binary files
+            err(filename + ': contains null bytes; not fixed\n')
+            f.close()
+            return 1
+        if lineno == 1 and g is None and line[:2] == '#!':
+            # Check for non-Python scripts
+            words = string.split(line[2:])
+            if words and re.search('[pP]ython', words[0]) < 0:
+                msg = filename + ': ' + words[0]
+                msg = msg + ' script; not fixed\n'
+                err(msg)
+                f.close()
+                return 1
+        while line[-2:] == '\\\n':
+            nextline = f.readline()
+            if not nextline: break
+            line = line + nextline
+            lineno = lineno + 1
+        newline = fixline(line)
+        if newline != line:
+            if g is None:
+                try:
+                    g = open(tempname, 'w')
+                except IOError, msg:
+                    f.close()
+                    err('%s: cannot create: %r\n' % (tempname, msg))
+                    return 1
+                f.seek(0)
+                lineno = 0
+                rep(filename + ':\n')
+                continue # restart from the beginning
+            rep(repr(lineno) + '\n')
+            rep('< ' + line)
+            rep('> ' + newline)
+        if g is not None:
+            g.write(newline)
+
+    # End of file
+    f.close()
+    if not g: return 0 # No changes
+
+    # Finishing touch -- move files
+
+    # First copy the file's mode to the temp file
+    try:
+        statbuf = os.stat(filename)
+        os.chmod(tempname, statbuf[ST_MODE] & 07777)
+    except os.error, msg:
+        err('%s: warning: chmod failed (%r)\n' % (tempname, msg))
+    # Then make a backup of the original file as filename~
+    try:
+        os.rename(filename, filename + '~')
+    except os.error, msg:
+        err('%s: warning: backup failed (%r)\n' % (filename, msg))
+    # Now move the temp file to the original file
+    try:
+        os.rename(tempname, filename)
+    except os.error, msg:
+        err('%s: rename failed (%r)\n' % (filename, msg))
+        return 1
+    # Return succes
+    return 0
+
+
+from tokenize import tokenprog
+
+match = {'if':':', 'elif':':', 'while':':', 'return':'\n', \
+         '(':')', '[':']', '{':'}', '`':'`'}
+
+def fixline(line):
+    # Quick check for easy case
+    if '=' not in line: return line
+
+    i, n = 0, len(line)
+    stack = []
+    while i < n:
+        j = tokenprog.match(line, i)
+        if j < 0:
+            # A bad token; forget about the rest of this line
+            print '(Syntax error:)'
+            print line,
+            return line
+        a, b = tokenprog.regs[3] # Location of the token proper
+        token = line[a:b]
+        i = i+j
+        if stack and token == stack[-1]:
+            del stack[-1]
+        elif match.has_key(token):
+            stack.append(match[token])
+        elif token == '=' and stack:
+            line = line[:a] + '==' + line[b:]
+            i, n = a + len('=='), len(line)
+        elif token == '==' and not stack:
+            print '(Warning: \'==\' at top level:)'
+            print line,
+    return line
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/fact.py b/sys/src/cmd/python/Demo/scripts/fact.py
new file mode 100755
index 000000000..03cab8bb8
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/fact.py
@@ -0,0 +1,49 @@
+#! /usr/bin/env python
+
+# Factorize numbers.
+# The algorithm is not efficient, but easy to understand.
+# If there are large factors, it will take forever to find them,
+# because we try all odd numbers between 3 and sqrt(n)...
+
+import sys
+from math import sqrt
+
+error = 'fact.error'            # exception
+
+def fact(n):
+    if n < 1: raise error   # fact() argument should be >= 1
+    if n == 1: return []    # special case
+    res = []
+    # Treat even factors special, so we can use i = i+2 later
+    while n%2 == 0:
+        res.append(2)
+        n = n/2
+    # Try odd numbers up to sqrt(n)
+    limit = sqrt(float(n+1))
+    i = 3
+    while i <= limit:
+        if n%i == 0:
+            res.append(i)
+            n = n/i
+            limit = sqrt(n+1)
+        else:
+            i = i+2
+    if n != 1:
+        res.append(n)
+    return res
+
+def main():
+    if len(sys.argv) > 1:
+        for arg in sys.argv[1:]:
+            n = eval(arg)
+            print n, fact(n)
+    else:
+        try:
+            while 1:
+                n = input()
+                print n, fact(n)
+        except EOFError:
+            pass
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/find-uname.py b/sys/src/cmd/python/Demo/scripts/find-uname.py
new file mode 100644
index 000000000..b76b9f0fe
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/find-uname.py
@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+"""
+For each argument on the command line, look for it in the set of all Unicode
+names.  Arguments are treated as case-insensitive regular expressions, e.g.:
+
+    % find-uname 'small letter a$' 'horizontal line'
+    *** small letter a$ matches ***
+    LATIN SMALL LETTER A (97)
+    COMBINING LATIN SMALL LETTER A (867)
+    CYRILLIC SMALL LETTER A (1072)
+    PARENTHESIZED LATIN SMALL LETTER A (9372)
+    CIRCLED LATIN SMALL LETTER A (9424)
+    FULLWIDTH LATIN SMALL LETTER A (65345)
+    *** horizontal line matches ***
+    HORIZONTAL LINE EXTENSION (9135)
+"""
+
+import unicodedata
+import sys
+import re
+
+def main(args):
+    unicode_names= []
+    for ix in range(sys.maxunicode+1):
+        try:
+            unicode_names.append( (ix, unicodedata.name(unichr(ix))) )
+        except ValueError: # no name for the character
+            pass
+    for arg in args:
+        pat = re.compile(arg, re.I)
+        matches = [(x,y) for (x,y) in unicode_names
+                       if pat.search(y) is not None]
+        if matches:
+            print "***", arg, "matches", "***"
+            for (x,y) in matches:
+                print "%s (%d)" % (y,x)
+
+if __name__ == "__main__":
+    main(sys.argv[1:])
diff --git a/sys/src/cmd/python/Demo/scripts/from.py b/sys/src/cmd/python/Demo/scripts/from.py
new file mode 100755
index 000000000..3c04fcd49
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/from.py
@@ -0,0 +1,35 @@
+#! /usr/bin/env python
+
+# Print From and Subject of messages in $MAIL.
+# Extension to multiple mailboxes and other bells & whistles are left
+# as exercises for the reader.
+
+import sys, os
+
+# Open mailbox file.  Exits with exception when this fails.
+
+try:
+    mailbox = os.environ['MAIL']
+except (AttributeError, KeyError):
+    sys.stderr.write('No environment variable $MAIL\n')
+    sys.exit(2)
+
+try:
+    mail = open(mailbox)
+except IOError:
+    sys.exit('Cannot open mailbox file: ' + mailbox)
+
+while 1:
+    line = mail.readline()
+    if not line:
+        break # EOF
+    if line.startswith('From '):
+        # Start of message found
+        print line[:-1],
+        while 1:
+            line = mail.readline()
+            if not line or line == '\n':
+                break
+            if line.startswith('Subject: '):
+                print repr(line[9:-1]),
+        print
diff --git a/sys/src/cmd/python/Demo/scripts/ftpstats.py b/sys/src/cmd/python/Demo/scripts/ftpstats.py
new file mode 100755
index 000000000..5c1599e66
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/ftpstats.py
@@ -0,0 +1,145 @@
+#! /usr/bin/env python
+
+# Extract statistics from ftp daemon log.
+
+# Usage:
+# ftpstats [-m maxitems] [-s search] [file]
+# -m maxitems: restrict number of items in "top-N" lists, default 25.
+# -s string:   restrict statistics to lines containing this string.
+# Default file is /usr/adm/ftpd;  a "-" means read standard input.
+
+# The script must be run on the host where the ftp daemon runs.
+# (At CWI this is currently buizerd.)
+
+import os
+import sys
+import re
+import string
+import getopt
+
+pat = '^([a-zA-Z0-9 :]*)!(.*)!(.*)!([<>].*)!([0-9]+)!([0-9]+)$'
+prog = re.compile(pat)
+
+def main():
+    maxitems = 25
+    search = None
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], 'm:s:')
+    except getopt.error, msg:
+        print msg
+        print 'usage: ftpstats [-m maxitems] [file]'
+        sys.exit(2)
+    for o, a in opts:
+        if o == '-m':
+            maxitems = string.atoi(a)
+        if o == '-s':
+            search = a
+    file = '/usr/adm/ftpd'
+    if args: file = args[0]
+    if file == '-':
+        f = sys.stdin
+    else:
+        try:
+            f = open(file, 'r')
+        except IOError, msg:
+            print file, ':', msg
+            sys.exit(1)
+    bydate = {}
+    bytime = {}
+    byfile = {}
+    bydir = {}
+    byhost = {}
+    byuser = {}
+    bytype = {}
+    lineno = 0
+    try:
+        while 1:
+            line = f.readline()
+            if not line: break
+            lineno = lineno + 1
+            if search and string.find(line, search) < 0:
+                continue
+            if prog.match(line) < 0:
+                print 'Bad line', lineno, ':', repr(line)
+                continue
+            items = prog.group(1, 2, 3, 4, 5, 6)
+            (logtime, loguser, loghost, logfile, logbytes,
+             logxxx2) = items
+##                      print logtime
+##                      print '-->', loguser
+##                      print '--> -->', loghost
+##                      print '--> --> -->', logfile
+##                      print '--> --> --> -->', logbytes
+##                      print '--> --> --> --> -->', logxxx2
+##                      for i in logtime, loghost, logbytes, logxxx2:
+##                              if '!' in i: print '???', i
+            add(bydate, logtime[-4:] + ' ' + logtime[:6], items)
+            add(bytime, logtime[7:9] + ':00-59', items)
+            direction, logfile = logfile[0], logfile[1:]
+            # The real path probably starts at the last //...
+            while 1:
+                i = string.find(logfile, '//')
+                if i < 0: break
+                logfile = logfile[i+1:]
+            add(byfile, logfile + ' ' + direction, items)
+            logdir = os.path.dirname(logfile)
+##              logdir = os.path.normpath(logdir) + '/.'
+            while 1:
+                add(bydir, logdir + ' ' + direction, items)
+                dirhead = os.path.dirname(logdir)
+                if dirhead == logdir: break
+                logdir = dirhead
+            add(byhost, loghost, items)
+            add(byuser, loguser, items)
+            add(bytype, direction, items)
+    except KeyboardInterrupt:
+        print 'Interrupted at line', lineno
+    show(bytype, 'by transfer direction', maxitems)
+    show(bydir, 'by directory', maxitems)
+    show(byfile, 'by file', maxitems)
+    show(byhost, 'by host', maxitems)
+    show(byuser, 'by user', maxitems)
+    showbar(bydate, 'by date')
+    showbar(bytime, 'by time of day')
+
+def showbar(dict, title):
+    n = len(title)
+    print '='*((70-n)/2), title, '='*((71-n)/2)
+    list = []
+    keys = dict.keys()
+    keys.sort()
+    for key in keys:
+        n = len(str(key))
+        list.append((len(dict[key]), key))
+    maxkeylength = 0
+    maxcount = 0
+    for count, key in list:
+        maxkeylength = max(maxkeylength, len(key))
+        maxcount = max(maxcount, count)
+    maxbarlength = 72 - maxkeylength - 7
+    for count, key in list:
+        barlength = int(round(maxbarlength*float(count)/maxcount))
+        bar = '*'*barlength
+        print '%5d %-*s %s' % (count, maxkeylength, key, bar)
+
+def show(dict, title, maxitems):
+    if len(dict) > maxitems:
+        title = title + ' (first %d)'%maxitems
+    n = len(title)
+    print '='*((70-n)/2), title, '='*((71-n)/2)
+    list = []
+    keys = dict.keys()
+    for key in keys:
+        list.append((-len(dict[key]), key))
+    list.sort()
+    for count, key in list[:maxitems]:
+        print '%5d %s' % (-count, key)
+
+def add(dict, key, item):
+    if dict.has_key(key):
+        dict[key].append(item)
+    else:
+        dict[key] = [item]
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/lpwatch.py b/sys/src/cmd/python/Demo/scripts/lpwatch.py
new file mode 100755
index 000000000..8887dee7d
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/lpwatch.py
@@ -0,0 +1,110 @@
+#! /usr/bin/env python
+
+# Watch line printer queue(s).
+# Intended for BSD 4.3 lpq.
+
+import posix
+import sys
+import time
+import string
+
+DEF_PRINTER = 'psc'
+DEF_DELAY = 10
+
+def main():
+    delay = DEF_DELAY # XXX Use getopt() later
+    try:
+        thisuser = posix.environ['LOGNAME']
+    except:
+        thisuser = posix.environ['USER']
+    printers = sys.argv[1:]
+    if printers:
+        # Strip '-P' from printer names just in case
+        # the user specified it...
+        for i in range(len(printers)):
+            if printers[i][:2] == '-P':
+                printers[i] = printers[i][2:]
+    else:
+        if posix.environ.has_key('PRINTER'):
+            printers = [posix.environ['PRINTER']]
+        else:
+            printers = [DEF_PRINTER]
+    #
+    clearhome = posix.popen('clear', 'r').read()
+    #
+    while 1:
+        text = clearhome
+        for name in printers:
+            text = text + makestatus(name, thisuser) + '\n'
+        print text
+        time.sleep(delay)
+
+def makestatus(name, thisuser):
+    pipe = posix.popen('lpq -P' + name + ' 2>&1', 'r')
+    lines = []
+    users = {}
+    aheadbytes = 0
+    aheadjobs = 0
+    userseen = 0
+    totalbytes = 0
+    totaljobs = 0
+    while 1:
+        line = pipe.readline()
+        if not line: break
+        fields = string.split(line)
+        n = len(fields)
+        if len(fields) >= 6 and fields[n-1] == 'bytes':
+            rank = fields[0]
+            user = fields[1]
+            job = fields[2]
+            files = fields[3:-2]
+            bytes = eval(fields[n-2])
+            if user == thisuser:
+                userseen = 1
+            elif not userseen:
+                aheadbytes = aheadbytes + bytes
+                aheadjobs = aheadjobs + 1
+            totalbytes = totalbytes + bytes
+            totaljobs = totaljobs + 1
+            if users.has_key(user):
+                ujobs, ubytes = users[user]
+            else:
+                ujobs, ubytes = 0, 0
+            ujobs = ujobs + 1
+            ubytes = ubytes + bytes
+            users[user] = ujobs, ubytes
+        else:
+            if fields and fields[0] <> 'Rank':
+                line = string.strip(line)
+                if line == 'no entries':
+                    line = name + ': idle'
+                elif line[-22:] == ' is ready and printing':
+                    line = name
+                lines.append(line)
+    #
+    if totaljobs:
+        line = '%d K' % ((totalbytes+1023)/1024)
+        if totaljobs <> len(users):
+            line = line + ' (%d jobs)' % totaljobs
+        if len(users) == 1:
+            line = line + ' for %s' % (users.keys()[0],)
+        else:
+            line = line + ' for %d users' % len(users)
+            if userseen:
+                if aheadjobs == 0:
+                    line =  line + ' (%s first)' % thisuser
+                else:
+                    line = line + ' (%d K before %s)' % (
+                                   (aheadbytes+1023)/1024, thisuser)
+        lines.append(line)
+    #
+    sts = pipe.close()
+    if sts:
+        lines.append('lpq exit status %r' % (sts,))
+    return string.joinfields(lines, ': ')
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
diff --git a/sys/src/cmd/python/Demo/scripts/makedir.py b/sys/src/cmd/python/Demo/scripts/makedir.py
new file mode 100755
index 000000000..f70facd08
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/makedir.py
@@ -0,0 +1,21 @@
+#! /usr/bin/env python
+
+# Like mkdir, but also make intermediate directories if necessary.
+# It is not an error if the given directory already exists (as long
+# as it is a directory).
+# Errors are not treated specially -- you just get a Python exception.
+
+import sys, os
+
+def main():
+    for p in sys.argv[1:]:
+        makedirs(p)
+
+def makedirs(p):
+    if p and not os.path.isdir(p):
+        head, tail = os.path.split(p)
+        makedirs(head)
+        os.mkdir(p, 0777)
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/markov.py b/sys/src/cmd/python/Demo/scripts/markov.py
new file mode 100755
index 000000000..bddec5693
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/markov.py
@@ -0,0 +1,117 @@
+#! /usr/bin/env python
+
+class Markov:
+    def __init__(self, histsize, choice):
+        self.histsize = histsize
+        self.choice = choice
+        self.trans = {}
+    def add(self, state, next):
+        if not self.trans.has_key(state):
+            self.trans[state] = [next]
+        else:
+            self.trans[state].append(next)
+    def put(self, seq):
+        n = self.histsize
+        add = self.add
+        add(None, seq[:0])
+        for i in range(len(seq)):
+            add(seq[max(0, i-n):i], seq[i:i+1])
+        add(seq[len(seq)-n:], None)
+    def get(self):
+        choice = self.choice
+        trans = self.trans
+        n = self.histsize
+        seq = choice(trans[None])
+        while 1:
+            subseq = seq[max(0, len(seq)-n):]
+            options = trans[subseq]
+            next = choice(options)
+            if not next: break
+            seq = seq + next
+        return seq
+
+def test():
+    import sys, string, random, getopt
+    args = sys.argv[1:]
+    try:
+        opts, args = getopt.getopt(args, '0123456789cdw')
+    except getopt.error:
+        print 'Usage: markov [-#] [-cddqw] [file] ...'
+        print 'Options:'
+        print '-#: 1-digit history size (default 2)'
+        print '-c: characters (default)'
+        print '-w: words'
+        print '-d: more debugging output'
+        print '-q: no debugging output'
+        print 'Input files (default stdin) are split in paragraphs'
+        print 'separated blank lines and each paragraph is split'
+        print 'in words by whitespace, then reconcatenated with'
+        print 'exactly one space separating words.'
+        print 'Output consists of paragraphs separated by blank'
+        print 'lines, where lines are no longer than 72 characters.'
+    histsize = 2
+    do_words = 0
+    debug = 1
+    for o, a in opts:
+        if '-0' <= o <= '-9': histsize = eval(o[1:])
+        if o == '-c': do_words = 0
+        if o == '-d': debug = debug + 1
+        if o == '-q': debug = 0
+        if o == '-w': do_words = 1
+    if not args: args = ['-']
+    m = Markov(histsize, random.choice)
+    try:
+        for filename in args:
+            if filename == '-':
+                f = sys.stdin
+                if f.isatty():
+                    print 'Sorry, need stdin from file'
+                    continue
+            else:
+                f = open(filename, 'r')
+            if debug: print 'processing', filename, '...'
+            text = f.read()
+            f.close()
+            paralist = string.splitfields(text, '\n\n')
+            for para in paralist:
+                if debug > 1: print 'feeding ...'
+                words = string.split(para)
+                if words:
+                    if do_words: data = tuple(words)
+                    else: data = string.joinfields(words, ' ')
+                    m.put(data)
+    except KeyboardInterrupt:
+        print 'Interrupted -- continue with data read so far'
+    if not m.trans:
+        print 'No valid input files'
+        return
+    if debug: print 'done.'
+    if debug > 1:
+        for key in m.trans.keys():
+            if key is None or len(key) < histsize:
+                print repr(key), m.trans[key]
+        if histsize == 0: print repr(''), m.trans['']
+        print
+    while 1:
+        data = m.get()
+        if do_words: words = data
+        else: words = string.split(data)
+        n = 0
+        limit = 72
+        for w in words:
+            if n + len(w) > limit:
+                print
+                n = 0
+            print w,
+            n = n + len(w) + 1
+        print
+        print
+
+def tuple(list):
+    if len(list) == 0: return ()
+    if len(list) == 1: return (list[0],)
+    i = len(list)/2
+    return tuple(list[:i]) + tuple(list[i:])
+
+if __name__ == "__main__":
+    test()
diff --git a/sys/src/cmd/python/Demo/scripts/mboxconvert.py b/sys/src/cmd/python/Demo/scripts/mboxconvert.py
new file mode 100755
index 000000000..8c462f3b1
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/mboxconvert.py
@@ -0,0 +1,124 @@
+#! /usr/bin/env python
+
+# Convert  MH directories (1 message per file) or MMDF mailboxes (4x^A
+# delimited) to unix mailbox (From ... delimited) on stdout.
+# If -f is given, files contain one message per file (e.g. MH messages)
+
+import rfc822
+import sys
+import time
+import os
+import stat
+import getopt
+import re
+
+def main():
+    dofile = mmdf
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], 'f')
+    except getopt.error, msg:
+        sys.stderr.write('%s\n' % msg)
+        sys.exit(2)
+    for o, a in opts:
+        if o == '-f':
+            dofile = message
+    if not args:
+        args = ['-']
+    sts = 0
+    for arg in args:
+        if arg == '-' or arg == '':
+            sts = dofile(sys.stdin) or sts
+        elif os.path.isdir(arg):
+            sts = mh(arg) or sts
+        elif os.path.isfile(arg):
+            try:
+                f = open(arg)
+            except IOError, msg:
+                sys.stderr.write('%s: %s\n' % (arg, msg))
+                sts = 1
+                continue
+            sts = dofile(f) or sts
+            f.close()
+        else:
+            sys.stderr.write('%s: not found\n' % arg)
+            sts = 1
+    if sts:
+        sys.exit(sts)
+
+numeric = re.compile('[1-9][0-9]*')
+
+def mh(dir):
+    sts = 0
+    msgs = os.listdir(dir)
+    for msg in msgs:
+        if numeric.match(msg) != len(msg):
+            continue
+        fn = os.path.join(dir, msg)
+        try:
+            f = open(fn)
+        except IOError, msg:
+            sys.stderr.write('%s: %s\n' % (fn, msg))
+            sts = 1
+            continue
+        sts = message(f) or sts
+    return sts
+
+def mmdf(f):
+    sts = 0
+    while 1:
+        line = f.readline()
+        if not line:
+            break
+        if line == '\1\1\1\1\n':
+            sts = message(f, line) or sts
+        else:
+            sys.stderr.write(
+                    'Bad line in MMFD mailbox: %r\n' % (line,))
+    return sts
+
+counter = 0 # for generating unique Message-ID headers
+
+def message(f, delimiter = ''):
+    sts = 0
+    # Parse RFC822 header
+    m = rfc822.Message(f)
+    # Write unix header line
+    fullname, email = m.getaddr('From')
+    tt = m.getdate('Date')
+    if tt:
+        t = time.mktime(tt)
+    else:
+        sys.stderr.write(
+                'Unparseable date: %r\n' % (m.getheader('Date'),))
+        t = os.fstat(f.fileno())[stat.ST_MTIME]
+    print 'From', email, time.ctime(t)
+    # Copy RFC822 header
+    for line in m.headers:
+        print line,
+    # Invent Message-ID header if none is present
+    if not m.has_key('message-id'):
+        global counter
+        counter = counter + 1
+        msgid = "<%s.%d>" % (hex(t), counter)
+        sys.stderr.write("Adding Message-ID %s (From %s)\n" %
+                         (msgid, email))
+        print "Message-ID:", msgid
+    print
+    # Copy body
+    while 1:
+        line = f.readline()
+        if line == delimiter:
+            break
+        if not line:
+            sys.stderr.write('Unexpected EOF in message\n')
+            sts = 1
+            break
+        if line[:5] == 'From ':
+            line = '>' + line
+        print line,
+    # Print trailing newline
+    print
+    return sts
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/mkrcs.py b/sys/src/cmd/python/Demo/scripts/mkrcs.py
new file mode 100755
index 000000000..cacdda0a5
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/mkrcs.py
@@ -0,0 +1,61 @@
+#! /usr/bin/env python
+
+# A rather specialized script to make sure that a symbolic link named
+# RCS exists pointing to a real RCS directory in a parallel tree
+# referenced as RCStree in an ancestor directory.
+# (I use this because I like my RCS files to reside on a physically
+# different machine).
+
+import os
+
+def main():
+    rcstree = 'RCStree'
+    rcs = 'RCS'
+    if os.path.islink(rcs):
+        print '%r is a symlink to %r' % (rcs, os.readlink(rcs))
+        return
+    if os.path.isdir(rcs):
+        print '%r is an ordinary directory' % (rcs,)
+        return
+    if os.path.exists(rcs):
+        print '%r is a file?!?!' % (rcs,)
+        return
+    #
+    p = os.getcwd()
+    up = ''
+    down = ''
+    # Invariants:
+    # (1) join(p, down) is the current directory
+    # (2) up is the same directory as p
+    # Ergo:
+    # (3) join(up, down) is the current directory
+    #print 'p =', repr(p)
+    while not os.path.isdir(os.path.join(p, rcstree)):
+        head, tail = os.path.split(p)
+        #print 'head = %r; tail = %r' % (head, tail)
+        if not tail:
+            print 'Sorry, no ancestor dir contains %r' % (rcstree,)
+            return
+        p = head
+        up = os.path.join(os.pardir, up)
+        down = os.path.join(tail, down)
+        #print 'p = %r; up = %r; down = %r' % (p, up, down)
+    there = os.path.join(up, rcstree)
+    there = os.path.join(there, down)
+    there = os.path.join(there, rcs)
+    if os.path.isdir(there):
+        print '%r already exists' % (there, )
+    else:
+        print 'making %r' % (there,)
+        makedirs(there)
+    print 'making symlink %r -> %r' % (rcs, there)
+    os.symlink(there, rcs)
+
+def makedirs(p):
+    if not os.path.isdir(p):
+        head, tail = os.path.split(p)
+        makedirs(head)
+        os.mkdir(p, 0777)
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/morse.py b/sys/src/cmd/python/Demo/scripts/morse.py
new file mode 100755
index 000000000..3da49da9e
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/morse.py
@@ -0,0 +1,149 @@
+# DAH should be three DOTs.
+# Space between DOTs and DAHs should be one DOT.
+# Space between two letters should be one DAH.
+# Space between two words should be DOT DAH DAH.
+
+import sys, math, audiodev
+
+DOT = 30
+DAH = 3 * DOT
+OCTAVE = 2                              # 1 == 441 Hz, 2 == 882 Hz, ...
+
+morsetab = {
+        'A': '.-',              'a': '.-',
+        'B': '-...',            'b': '-...',
+        'C': '-.-.',            'c': '-.-.',
+        'D': '-..',             'd': '-..',
+        'E': '.',               'e': '.',
+        'F': '..-.',            'f': '..-.',
+        'G': '--.',             'g': '--.',
+        'H': '....',            'h': '....',
+        'I': '..',              'i': '..',
+        'J': '.---',            'j': '.---',
+        'K': '-.-',             'k': '-.-',
+        'L': '.-..',            'l': '.-..',
+        'M': '--',              'm': '--',
+        'N': '-.',              'n': '-.',
+        'O': '---',             'o': '---',
+        'P': '.--.',            'p': '.--.',
+        'Q': '--.-',            'q': '--.-',
+        'R': '.-.',             'r': '.-.',
+        'S': '...',             's': '...',
+        'T': '-',               't': '-',
+        'U': '..-',             'u': '..-',
+        'V': '...-',            'v': '...-',
+        'W': '.--',             'w': '.--',
+        'X': '-..-',            'x': '-..-',
+        'Y': '-.--',            'y': '-.--',
+        'Z': '--..',            'z': '--..',
+        '0': '-----',
+        '1': '.----',
+        '2': '..---',
+        '3': '...--',
+        '4': '....-',
+        '5': '.....',
+        '6': '-....',
+        '7': '--...',
+        '8': '---..',
+        '9': '----.',
+        ',': '--..--',
+        '.': '.-.-.-',
+        '?': '..--..',
+        ';': '-.-.-.',
+        ':': '---...',
+        "'": '.----.',
+        '-': '-....-',
+        '/': '-..-.',
+        '(': '-.--.-',
+        ')': '-.--.-',
+        '_': '..--.-',
+        ' ': ' '
+}
+
+# If we play at 44.1 kHz (which we do), then if we produce one sine
+# wave in 100 samples, we get a tone of 441 Hz.  If we produce two
+# sine waves in these 100 samples, we get a tone of 882 Hz.  882 Hz
+# appears to be a nice one for playing morse code.
+def mkwave(octave):
+    global sinewave, nowave
+    sinewave = ''
+    for i in range(100):
+        val = int(math.sin(math.pi * float(i) * octave / 50.0) * 30000)
+        sinewave = sinewave + chr((val >> 8) & 255) + chr(val & 255)
+    nowave = '\0' * 200
+
+mkwave(OCTAVE)
+
+def main():
+    import getopt, string
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], 'o:p:')
+    except getopt.error:
+        sys.stderr.write('Usage ' + sys.argv[0] +
+                         ' [ -o outfile ] [ args ] ...\n')
+        sys.exit(1)
+    dev = None
+    for o, a in opts:
+        if o == '-o':
+            import aifc
+            dev = aifc.open(a, 'w')
+            dev.setframerate(44100)
+            dev.setsampwidth(2)
+            dev.setnchannels(1)
+        if o == '-p':
+            mkwave(string.atoi(a))
+    if not dev:
+        import audiodev
+        dev = audiodev.AudioDev()
+        dev.setoutrate(44100)
+        dev.setsampwidth(2)
+        dev.setnchannels(1)
+        dev.close = dev.stop
+        dev.writeframesraw = dev.writeframes
+    if args:
+        line = string.join(args)
+    else:
+        line = sys.stdin.readline()
+    while line:
+        mline = morse(line)
+        play(mline, dev)
+        if hasattr(dev, 'wait'):
+            dev.wait()
+        if not args:
+            line = sys.stdin.readline()
+        else:
+            line = ''
+    dev.close()
+
+# Convert a string to morse code with \001 between the characters in
+# the string.
+def morse(line):
+    res = ''
+    for c in line:
+        try:
+            res = res + morsetab[c] + '\001'
+        except KeyError:
+            pass
+    return res
+
+# Play a line of morse code.
+def play(line, dev):
+    for c in line:
+        if c == '.':
+            sine(dev, DOT)
+        elif c == '-':
+            sine(dev, DAH)
+        else:                   # space
+            pause(dev, DAH + DOT)
+        pause(dev, DOT)
+
+def sine(dev, length):
+    for i in range(length):
+        dev.writeframesraw(sinewave)
+
+def pause(dev, length):
+    for i in range(length):
+        dev.writeframesraw(nowave)
+
+if __name__ == '__main__' or sys.argv[0] == __name__:
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/newslist.doc b/sys/src/cmd/python/Demo/scripts/newslist.doc
new file mode 100755
index 000000000..87fd9ba27
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/newslist.doc
@@ -0,0 +1,59 @@
+                             NEWSLIST
+                             ========    
+            A program to assist HTTP browsing of newsgroups
+            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+WWW browsers such as NCSA Mosaic allow the user to read newsgroup
+articles by specifying the group name in a URL eg 'news:comp.answers'.
+
+To browse through many groups, though, (and there are several thousand
+of them) you really need a page or pages containing links to all the
+groups. There are some good ones out there, for example,
+
+    http://info.cern.ch/hypertext/DataSources/News/Groups/Overview.html
+
+is the standard one at CERN, but it only shows the groups available there,
+which may be rather different from those available on your machine.
+
+Newslist is a program which creates a hierarchy of pages for you based
+on the groups available from YOUR server. It is written in python - a
+splendid interpreted object-oriented language which I suggest you get
+right now from the directory /pub/python at ftp.cwi.nl, if you haven't
+already got it.
+
+You should be able to see some sample output by looking at:
+   http://pelican.cl.cam.ac.uk/newspage/root.html
+
+Descriptions of newsgroups can be added from a file with one group
+per line. eg:
+
+	alt.foo   Articles about foo
+	comp.bar  Programming in 'bar' and related languages
+
+A suitable list detailing most groups can be found at ftp.uu.net in
+/uunet-info/newsgroups.gz.
+
+Make sure you read the information at the beginning of the program source and
+configure the variables before running.
+
+In addition to python, you need:
+
+	An NNTP-based news feed.
+	A directory in which to put the pages.
+
+The programming is not very beautiful, but it works!  It comes with no
+warranty, express or implied, but with the hope that some others may
+find it useful.
+
+Comments, improvements & suggestions welcomed.
+Quentin Stafford-Fraser
+
+ ----------------------------------------------------------------------
+                       Quentin Stafford-Fraser
+            http://pelican.cl.cam.ac.uk/people/qs101/me.html
+ 
+ Cambridge University Computer Lab        Rank Xerox Cambridge EuroPARC
+ qs101@cl.cam.ac.uk                           fraser@europarc.xerox.com
+ Tel: +44 223 334411                                Tel: +44 223 341521
+ Fax: +44 223 334679                                Fax: +44 223 341510
+ ----------------------------------------------------------------------
diff --git a/sys/src/cmd/python/Demo/scripts/newslist.py b/sys/src/cmd/python/Demo/scripts/newslist.py
new file mode 100755
index 000000000..35ba48a48
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/newslist.py
@@ -0,0 +1,366 @@
+#! /usr/bin/env python
+#######################################################################
+# Newslist  $Revision: 37320 $
+#
+# Syntax:
+#    newslist [ -a ]
+#
+# This is a program to create a directory full of HTML pages
+# which between them contain links to all the newsgroups available
+# on your server.
+#
+# The -a option causes a complete list of all groups to be read from
+# the server rather than just the ones which have appeared since last
+# execution. This recreates the local list from scratch. Use this on
+# the first invocation of the program, and from time to time thereafter.
+#   When new groups are first created they may appear on your server as
+# empty groups. By default, empty groups are ignored by the -a option.
+# However, these new groups will not be created again, and so will not
+# appear in the server's list of 'new groups' at a later date. Hence it
+# won't appear until you do a '-a' after some articles have appeared.
+#
+# I should really keep a list of ignored empty groups and re-check them
+# for articles on every run, but I haven't got around to it yet.
+#
+# This assumes an NNTP news feed.
+#
+# Feel free to copy, distribute and modify this code for
+# non-commercial use. If you make any useful modifications, let me
+# know!
+#
+# (c) Quentin Stafford-Fraser 1994
+# fraser@europarc.xerox.com                     qs101@cl.cam.ac.uk
+#                                                                     #
+#######################################################################
+import sys,nntplib, string, marshal, time, os, posix, string
+
+#######################################################################
+# Check these variables before running!                               #
+
+# Top directory.
+# Filenames which don't start with / are taken as being relative to this.
+topdir='/anfs/qsbigdisc/web/html/newspage'
+
+# The name of your NNTP host
+# eg.
+#    newshost = 'nntp-serv.cl.cam.ac.uk'
+# or use following to get the name from the NNTPSERVER environment
+# variable:
+#    newshost = posix.environ['NNTPSERVER']
+newshost = 'nntp-serv.cl.cam.ac.uk'
+
+# The filename for a local cache of the newsgroup list
+treefile = 'grouptree'
+
+# The filename for descriptions of newsgroups
+# I found a suitable one at ftp.uu.net in /uunet-info/newgroups.gz
+# You can set this to '' if you don't wish to use one.
+descfile = 'newsgroups'
+
+# The directory in which HTML pages should be created
+# eg.
+#   pagedir  = '/usr/local/lib/html/newspage'
+#   pagedir  = 'pages'
+pagedir  = topdir
+
+# The html prefix which will refer to this directory
+# eg.
+#   httppref = '/newspage/',
+# or leave blank for relative links between pages: (Recommended)
+#   httppref = ''
+httppref = ''
+
+# The name of the 'root' news page in this directory.
+# A .html suffix will be added.
+rootpage = 'root'
+
+# Set skipempty to 0 if you wish to see links to empty groups as well.
+# Only affects the -a option.
+skipempty = 1
+
+# pagelinkicon can contain html to put an icon after links to
+# further pages. This helps to make important links stand out.
+# Set to '' if not wanted, or '...' is quite a good one.
+pagelinkicon='... <img src="http://pelican.cl.cam.ac.uk/icons/page.xbm"> '
+
+# ---------------------------------------------------------------------
+# Less important personal preferences:
+
+# Sublistsize controls the maximum number of items the will appear as
+# an indented sub-list before the whole thing is moved onto a different
+# page. The smaller this is, the more pages you will have, but the
+# shorter each will be.
+sublistsize = 4
+
+# That should be all.                                                 #
+#######################################################################
+
+for dir in os.curdir, os.environ['HOME']:
+    rcfile = os.path.join(dir, '.newslistrc.py')
+    if os.path.exists(rcfile):
+        print rcfile
+        execfile(rcfile)
+        break
+
+from nntplib import NNTP
+from stat import *
+
+rcsrev = '$Revision: 37320 $'
+rcsrev = string.join(filter(lambda s: '$' not in s, string.split(rcsrev)))
+desc = {}
+
+# Make (possibly) relative filenames into absolute ones
+treefile = os.path.join(topdir,treefile)
+descfile = os.path.join(topdir,descfile)
+page = os.path.join(topdir,pagedir)
+
+# First the bits for creating trees ---------------------------
+
+# Addtotree creates/augments a tree from a list of group names
+def addtotree(tree, groups):
+    print 'Updating tree...'
+    for i in groups:
+        parts = string.splitfields(i,'.')
+        makeleaf(tree, parts)
+
+# Makeleaf makes a leaf and the branch leading to it if necessary
+def makeleaf(tree,path):
+    j = path[0]
+    l = len(path)
+
+    if not tree.has_key(j):
+        tree[j] = {}
+    if l == 1:
+        tree[j]['.'] = '.'
+    if l > 1:
+        makeleaf(tree[j],path[1:])
+
+# Then the bits for outputting trees as pages ----------------
+
+# Createpage creates an HTML file named <root>.html containing links
+# to those groups beginning with <root>.
+
+def createpage(root, tree, p):
+    filename = os.path.join(pagedir,root+'.html')
+    if root == rootpage:
+        detail = ''
+    else:
+        detail = ' under ' + root
+    f = open(filename,'w')
+    # f.write('Content-Type: text/html\n')
+    f.write('<TITLE>Newsgroups available' + detail + '</TITLE>\n')
+    f.write('<H1>Newsgroups available' + detail +'</H1>\n')
+    f.write('<A HREF="'+httppref+rootpage+'.html">Back to top level</A><P>\n')
+    printtree(f,tree,0,p)
+    f.write('<I>This page automatically created by \'newslist\' v. '+rcsrev+'.')
+    f.write(time.ctime(time.time()) + '</I><P>')
+    f.close()
+
+# Printtree prints the groups as a bulleted list.  Groups with
+# more than <sublistsize> subgroups will be put on a separate page.
+# Other sets of subgroups are just indented.
+
+def printtree(f, tree, indent, p):
+    global desc
+    l = len(tree)
+
+    if l > sublistsize and indent>0:
+        # Create a new page and a link to it
+        f.write('<LI><B><A HREF="'+httppref+p[1:]+'.html">')
+        f.write(p[1:]+'.*')
+        f.write('</A></B>'+pagelinkicon+'\n')
+        createpage(p[1:], tree, p)
+        return
+
+    kl = tree.keys()
+
+    if l > 1:
+        kl.sort()
+        if indent > 0:
+            # Create a sub-list
+            f.write('<LI>'+p[1:]+'\n<UL>')
+        else:
+            # Create a main list
+            f.write('<UL>')
+        indent = indent + 1
+
+    for i in kl:
+        if i == '.':
+            # Output a newsgroup
+            f.write('<LI><A HREF="news:' + p[1:] + '">'+ p[1:] + '</A> ')
+            if desc.has_key(p[1:]):
+                f.write('     <I>'+desc[p[1:]]+'</I>\n')
+            else:
+                f.write('\n')
+        else:
+            # Output a hierarchy
+            printtree(f,tree[i], indent, p+'.'+i)
+
+    if l > 1:
+        f.write('\n</UL>')
+
+# Reading descriptions file ---------------------------------------
+
+# This returns an array mapping group name to its description
+
+def readdesc(descfile):
+    global desc
+
+    desc = {}
+
+    if descfile == '':
+        return
+
+    try:
+        d = open(descfile, 'r')
+        print 'Reading descriptions...'
+    except (IOError):
+        print 'Failed to open description file ' + descfile
+        return
+    l = d.readline()
+    while l != '':
+        bits = string.split(l)
+        try:
+            grp = bits[0]
+            dsc = string.join(bits[1:])
+            if len(dsc)>1:
+                desc[grp] = dsc
+        except (IndexError):
+            pass
+        l = d.readline()
+
+# Check that ouput directory exists, ------------------------------
+# and offer to create it if not
+
+def checkopdir(pagedir):
+    if not os.path.isdir(pagedir):
+        print 'Directory '+pagedir+' does not exist.'
+        print 'Shall I create it for you? (y/n)'
+        if sys.stdin.readline()[0] == 'y':
+            try:
+                os.mkdir(pagedir,0777)
+            except:
+                print 'Sorry - failed!'
+                sys.exit(1)
+        else:
+            print 'OK. Exiting.'
+            sys.exit(1)
+
+# Read and write current local tree ----------------------------------
+
+def readlocallist(treefile):
+    print 'Reading current local group list...'
+    tree = {}
+    try:
+        treetime = time.localtime(os.stat(treefile)[ST_MTIME])
+    except:
+        print '\n*** Failed to open local group cache '+treefile
+        print 'If this is the first time you have run newslist, then'
+        print 'use the -a option to create it.'
+        sys.exit(1)
+    treedate = '%02d%02d%02d' % (treetime[0] % 100 ,treetime[1], treetime[2])
+    try:
+        dump = open(treefile,'r')
+        tree = marshal.load(dump)
+        dump.close()
+    except (IOError):
+        print 'Cannot open local group list ' + treefile
+    return (tree, treedate)
+
+def writelocallist(treefile, tree):
+    try:
+        dump = open(treefile,'w')
+        groups = marshal.dump(tree,dump)
+        dump.close()
+        print 'Saved list to '+treefile+'\n'
+    except:
+        print 'Sorry - failed to write to local group cache '+treefile
+        print 'Does it (or its directory) have the correct permissions?'
+        sys.exit(1)
+
+# Return list of all groups on server -----------------------------
+
+def getallgroups(server):
+    print 'Getting list of all groups...'
+    treedate='010101'
+    info = server.list()[1]
+    groups = []
+    print 'Processing...'
+    if skipempty:
+        print '\nIgnoring following empty groups:'
+    for i in info:
+        grpname = string.split(i[0])[0]
+        if skipempty and string.atoi(i[1]) < string.atoi(i[2]):
+            print grpname+' ',
+        else:
+            groups.append(grpname)
+    print '\n'
+    if skipempty:
+        print '(End of empty groups)'
+    return groups
+
+# Return list of new groups on server -----------------------------
+
+def getnewgroups(server, treedate):
+    print 'Getting list of new groups since start of '+treedate+'...',
+    info = server.newgroups(treedate,'000001')[1]
+    print 'got %d.' % len(info)
+    print 'Processing...',
+    groups = []
+    for i in info:
+        grpname = string.split(i)[0]
+        groups.append(grpname)
+    print 'Done'
+    return groups
+
+# Now the main program --------------------------------------------
+
+def main():
+    global desc
+
+    tree={}
+
+    # Check that the output directory exists
+    checkopdir(pagedir);
+
+    try:
+        print 'Connecting to '+newshost+'...'
+        if sys.version[0] == '0':
+            s = NNTP.init(newshost)
+        else:
+            s = NNTP(newshost)
+        connected = 1
+    except (nntplib.error_temp, nntplib.error_perm), x:
+        print 'Error connecting to host:', x
+        print 'I\'ll try to use just the local list.'
+        connected = 0
+
+    # If -a is specified, read the full list of groups from server
+    if connected and len(sys.argv) > 1 and sys.argv[1] == '-a':
+
+        groups = getallgroups(s)
+
+    # Otherwise just read the local file and then add
+    # groups created since local file last modified.
+    else:
+
+        (tree, treedate) = readlocallist(treefile)
+        if connected:
+            groups = getnewgroups(s, treedate)
+
+    if connected:
+        addtotree(tree, groups)
+        writelocallist(treefile,tree)
+
+    # Read group descriptions
+    readdesc(descfile)
+
+    print 'Creating pages...'
+    createpage(rootpage, tree, '')
+    print 'Done'
+
+if __name__ == "__main__":
+    main()
+
+# That's all folks
+######################################################################
diff --git a/sys/src/cmd/python/Demo/scripts/pi.py b/sys/src/cmd/python/Demo/scripts/pi.py
new file mode 100755
index 000000000..9b242451a
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/pi.py
@@ -0,0 +1,34 @@
+#! /usr/bin/env python
+
+# Print digits of pi forever.
+#
+# The algorithm, using Python's 'long' integers ("bignums"), works
+# with continued fractions, and was conceived by Lambert Meertens.
+#
+# See also the ABC Programmer's Handbook, by Geurts, Meertens & Pemberton,
+# published by Prentice-Hall (UK) Ltd., 1990.
+
+import sys
+
+def main():
+    k, a, b, a1, b1 = 2L, 4L, 1L, 12L, 4L
+    while 1:
+        # Next approximation
+        p, q, k = k*k, 2L*k+1L, k+1L
+        a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1
+        # Print common digits
+        d, d1 = a/b, a1/b1
+        while d == d1:
+            output(d)
+            a, a1 = 10L*(a%b), 10L*(a1%b1)
+            d, d1 = a/b, a1/b1
+
+def output(d):
+    # Use write() to avoid spaces between the digits
+    # Use str() to avoid the 'L'
+    sys.stdout.write(str(d))
+    # Flush so the output is seen immediately
+    sys.stdout.flush()
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/pp.py b/sys/src/cmd/python/Demo/scripts/pp.py
new file mode 100755
index 000000000..0491fa9bf
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/pp.py
@@ -0,0 +1,130 @@
+#! /usr/bin/env python
+
+# Emulate some Perl command line options.
+# Usage: pp [-a] [-c] [-d] [-e scriptline] [-F fieldsep] [-n] [-p] [file] ...
+# Where the options mean the following:
+#   -a            : together with -n or -p, splits each line into list F
+#   -c            : check syntax only, do not execute any code
+#   -d            : run the script under the debugger, pdb
+#   -e scriptline : gives one line of the Python script; may be repeated
+#   -F fieldsep   : sets the field separator for the -a option [not in Perl]
+#   -n            : runs the script for each line of input
+#   -p            : prints the line after the script has run
+# When no script lines have been passed, the first file argument
+# contains the script.  With -n or -p, the remaining arguments are
+# read as input to the script, line by line.  If a file is '-'
+# or missing, standard input is read.
+
+# XXX To do:
+# - add -i extension option (change files in place)
+# - make a single loop over the files and lines (changes effect of 'break')?
+# - add an option to specify the record separator
+# - except for -n/-p, run directly from the file if at all possible
+
+import sys
+import string
+import getopt
+
+FS = ''
+SCRIPT = []
+AFLAG = 0
+CFLAG = 0
+DFLAG = 0
+NFLAG = 0
+PFLAG = 0
+
+try:
+    optlist, ARGS = getopt.getopt(sys.argv[1:], 'acde:F:np')
+except getopt.error, msg:
+    sys.stderr.write(sys.argv[0] + ': ' + msg + '\n')
+    sys.exit(2)
+
+for option, optarg in optlist:
+    if option == '-a':
+        AFLAG = 1
+    elif option == '-c':
+        CFLAG = 1
+    elif option == '-d':
+        DFLAG = 1
+    elif option == '-e':
+        for line in string.splitfields(optarg, '\n'):
+            SCRIPT.append(line)
+    elif option == '-F':
+        FS = optarg
+    elif option == '-n':
+        NFLAG = 1
+        PFLAG = 0
+    elif option == '-p':
+        NFLAG = 1
+        PFLAG = 1
+    else:
+        print option, 'not recognized???'
+
+if not ARGS: ARGS.append('-')
+
+if not SCRIPT:
+    if ARGS[0] == '-':
+        fp = sys.stdin
+    else:
+        fp = open(ARGS[0], 'r')
+    while 1:
+        line = fp.readline()
+        if not line: break
+        SCRIPT.append(line[:-1])
+    del fp
+    del ARGS[0]
+    if not ARGS: ARGS.append('-')
+
+if CFLAG:
+    prologue = ['if 0:']
+    epilogue = []
+elif NFLAG:
+    # Note that it is on purpose that AFLAG and PFLAG are
+    # tested dynamically each time through the loop
+    prologue = [ \
+            'LINECOUNT = 0', \
+            'for FILE in ARGS:', \
+            '   \tif FILE == \'-\':', \
+            '   \t   \tFP = sys.stdin', \
+            '   \telse:', \
+            '   \t   \tFP = open(FILE, \'r\')', \
+            '   \tLINENO = 0', \
+            '   \twhile 1:', \
+            '   \t   \tLINE = FP.readline()', \
+            '   \t   \tif not LINE: break', \
+            '   \t   \tLINENO = LINENO + 1', \
+            '   \t   \tLINECOUNT = LINECOUNT + 1', \
+            '   \t   \tL = LINE[:-1]', \
+            '   \t   \taflag = AFLAG', \
+            '   \t   \tif aflag:', \
+            '   \t   \t   \tif FS: F = string.splitfields(L, FS)', \
+            '   \t   \t   \telse: F = string.split(L)' \
+            ]
+    epilogue = [ \
+            '   \t   \tif not PFLAG: continue', \
+            '   \t   \tif aflag:', \
+            '   \t   \t   \tif FS: print string.joinfields(F, FS)', \
+            '   \t   \t   \telse: print string.join(F)', \
+            '   \t   \telse: print L', \
+            ]
+else:
+    prologue = ['if 1:']
+    epilogue = []
+
+# Note that we indent using tabs only, so that any indentation style
+# used in 'command' will come out right after re-indentation.
+
+program = string.joinfields(prologue, '\n') + '\n'
+for line in SCRIPT:
+    program = program + ('   \t   \t' + line + '\n')
+program = program + (string.joinfields(epilogue, '\n') + '\n')
+
+import tempfile
+fp = tempfile.NamedTemporaryFile()
+fp.write(program)
+fp.flush()
+if DFLAG:
+    import pdb
+    pdb.run('execfile(%r)' % (tfn,))
+else:
+    execfile(tfn)
diff --git a/sys/src/cmd/python/Demo/scripts/primes.py b/sys/src/cmd/python/Demo/scripts/primes.py
new file mode 100755
index 000000000..5935a3c84
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/primes.py
@@ -0,0 +1,27 @@
+#! /usr/bin/env python
+
+# Print prime numbers in a given range
+
+def main():
+    import sys
+    min, max = 2, 0x7fffffff
+    if sys.argv[1:]:
+        min = int(eval(sys.argv[1]))
+        if sys.argv[2:]:
+            max = int(eval(sys.argv[2]))
+    primes(min, max)
+
+def primes(min, max):
+    if 2 >= min: print 2
+    primes = [2]
+    i = 3
+    while i <= max:
+        for p in primes:
+            if i%p == 0 or p*p > i: break
+        if i%p <> 0:
+            primes.append(i)
+            if i >= min: print i
+        i = i+2
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/queens.py b/sys/src/cmd/python/Demo/scripts/queens.py
new file mode 100755
index 000000000..74756be7d
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/queens.py
@@ -0,0 +1,85 @@
+#! /usr/bin/env python
+
+"""N queens problem.
+
+The (well-known) problem is due to Niklaus Wirth.
+
+This solution is inspired by Dijkstra (Structured Programming).  It is
+a classic recursive backtracking approach.
+
+"""
+
+N = 8                                   # Default; command line overrides
+
+class Queens:
+
+    def __init__(self, n=N):
+        self.n = n
+        self.reset()
+
+    def reset(self):
+        n = self.n
+        self.y = [None]*n               # Where is the queen in column x
+        self.row = [0]*n                # Is row[y] safe?
+        self.up = [0] * (2*n-1)         # Is upward diagonal[x-y] safe?
+        self.down = [0] * (2*n-1)       # Is downward diagonal[x+y] safe?
+        self.nfound = 0                 # Instrumentation
+
+    def solve(self, x=0):               # Recursive solver
+        for y in range(self.n):
+            if self.safe(x, y):
+                self.place(x, y)
+                if x+1 == self.n:
+                    self.display()
+                else:
+                    self.solve(x+1)
+                self.remove(x, y)
+
+    def safe(self, x, y):
+        return not self.row[y] and not self.up[x-y] and not self.down[x+y]
+
+    def place(self, x, y):
+        self.y[x] = y
+        self.row[y] = 1
+        self.up[x-y] = 1
+        self.down[x+y] = 1
+
+    def remove(self, x, y):
+        self.y[x] = None
+        self.row[y] = 0
+        self.up[x-y] = 0
+        self.down[x+y] = 0
+
+    silent = 0                          # If set, count solutions only
+
+    def display(self):
+        self.nfound = self.nfound + 1
+        if self.silent:
+            return
+        print '+-' + '--'*self.n + '+'
+        for y in range(self.n-1, -1, -1):
+            print '|',
+            for x in range(self.n):
+                if self.y[x] == y:
+                    print "Q",
+                else:
+                    print ".",
+            print '|'
+        print '+-' + '--'*self.n + '+'
+
+def main():
+    import sys
+    silent = 0
+    n = N
+    if sys.argv[1:2] == ['-n']:
+        silent = 1
+        del sys.argv[1]
+    if sys.argv[1:]:
+        n = int(sys.argv[1])
+    q = Queens(n)
+    q.silent = silent
+    q.solve()
+    print "Found", q.nfound, "solutions."
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/script.py b/sys/src/cmd/python/Demo/scripts/script.py
new file mode 100755
index 000000000..6eaa7aec2
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/script.py
@@ -0,0 +1,33 @@
+#! /usr/bin/env python
+# script.py -- Make typescript of terminal session.
+# Usage:
+#       -a      Append to typescript.
+#       -p      Use Python as shell.
+# Author: Steen Lumholt.
+
+
+import os, time, sys
+import pty
+
+def read(fd):
+    data = os.read(fd, 1024)
+    file.write(data)
+    return data
+
+shell = 'sh'
+filename = 'typescript'
+mode = 'w'
+if os.environ.has_key('SHELL'):
+    shell = os.environ['SHELL']
+if '-a' in sys.argv:
+    mode = 'a'
+if '-p' in sys.argv:
+    shell = 'python'
+
+file = open(filename, mode)
+
+sys.stdout.write('Script started, file is %s\n' % filename)
+file.write('Script started on %s\n' % time.ctime(time.time()))
+pty.spawn(shell, read)
+file.write('Script done on %s\n' % time.ctime(time.time()))
+sys.stdout.write('Script done, file is %s\n' % filename)
diff --git a/sys/src/cmd/python/Demo/scripts/unbirthday.py b/sys/src/cmd/python/Demo/scripts/unbirthday.py
new file mode 100755
index 000000000..2d0b8e5f4
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/unbirthday.py
@@ -0,0 +1,107 @@
+#! /usr/bin/env python
+
+# Calculate your unbirthday count (see Alice in Wonderland).
+# This is defined as the number of days from your birth until today
+# that weren't your birthday.  (The day you were born is not counted).
+# Leap years make it interesting.
+
+import sys
+import time
+import calendar
+
+def main():
+    # Note that the range checks below also check for bad types,
+    # e.g. 3.14 or ().  However syntactically invalid replies
+    # will raise an exception.
+    if sys.argv[1:]:
+        year = int(sys.argv[1])
+    else:
+        year = int(raw_input('In which year were you born? '))
+    if 0<=year<100:
+        print "I'll assume that by", year,
+        year = year + 1900
+        print 'you mean', year, 'and not the early Christian era'
+    elif not (1850<=year<=2002):
+        print "It's hard to believe you were born in", year
+        return
+    #
+    if sys.argv[2:]:
+        month = int(sys.argv[2])
+    else:
+        month = int(raw_input('And in which month? (1-12) '))
+    if not (1<=month<=12):
+        print 'There is no month numbered', month
+        return
+    #
+    if sys.argv[3:]:
+        day = int(sys.argv[3])
+    else:
+        day = int(raw_input('And on what day of that month? (1-31) '))
+    if month == 2 and calendar.isleap(year):
+        maxday = 29
+    else:
+        maxday = calendar.mdays[month]
+    if not (1<=day<=maxday):
+        print 'There are no', day, 'days in that month!'
+        return
+    #
+    bdaytuple = (year, month, day)
+    bdaydate = mkdate(bdaytuple)
+    print 'You were born on', format(bdaytuple)
+    #
+    todaytuple = time.localtime()[:3]
+    todaydate = mkdate(todaytuple)
+    print 'Today is', format(todaytuple)
+    #
+    if bdaytuple > todaytuple:
+        print 'You are a time traveler.  Go back to the future!'
+        return
+    #
+    if bdaytuple == todaytuple:
+        print 'You were born today.  Have a nice life!'
+        return
+    #
+    days = todaydate - bdaydate
+    print 'You have lived', days, 'days'
+    #
+    age = 0
+    for y in range(year, todaytuple[0] + 1):
+        if bdaytuple < (y, month, day) <= todaytuple:
+            age = age + 1
+    #
+    print 'You are', age, 'years old'
+    #
+    if todaytuple[1:] == bdaytuple[1:]:
+        print 'Congratulations!  Today is your', nth(age), 'birthday'
+        print 'Yesterday was your',
+    else:
+        print 'Today is your',
+    print nth(days - age), 'unbirthday'
+
+def format((year, month, day)):
+    return '%d %s %d' % (day, calendar.month_name[month], year)
+
+def nth(n):
+    if n == 1: return '1st'
+    if n == 2: return '2nd'
+    if n == 3: return '3rd'
+    return '%dth' % n
+
+def mkdate((year, month, day)):
+    # Januari 1st, in 0 A.D. is arbitrarily defined to be day 1,
+    # even though that day never actually existed and the calendar
+    # was different then...
+    days = year*365                 # years, roughly
+    days = days + (year+3)/4        # plus leap years, roughly
+    days = days - (year+99)/100     # minus non-leap years every century
+    days = days + (year+399)/400    # plus leap years every 4 centirues
+    for i in range(1, month):
+        if i == 2 and calendar.isleap(year):
+            days = days + 29
+        else:
+            days = days + calendar.mdays[i]
+    days = days + day
+    return days
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/update.py b/sys/src/cmd/python/Demo/scripts/update.py
new file mode 100755
index 000000000..c9360260e
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/update.py
@@ -0,0 +1,92 @@
+#! /usr/bin/env python
+
+# Update a bunch of files according to a script.
+# The input file contains lines of the form <filename>:<lineno>:<text>,
+# meaning that the given line of the given file is to be replaced
+# by the given text.  This is useful for performing global substitutions
+# on grep output:
+
+import os
+import sys
+import re
+
+pat = '^([^: \t\n]+):([1-9][0-9]*):'
+prog = re.compile(pat)
+
+class FileObj:
+    def __init__(self, filename):
+        self.filename = filename
+        self.changed = 0
+        try:
+            self.lines = open(filename, 'r').readlines()
+        except IOError, msg:
+            print '*** Can\'t open "%s":' % filename, msg
+            self.lines = None
+            return
+        print 'diffing', self.filename
+
+    def finish(self):
+        if not self.changed:
+            print 'no changes to', self.filename
+            return
+        try:
+            os.rename(self.filename, self.filename + '~')
+            fp = open(self.filename, 'w')
+        except (os.error, IOError), msg:
+            print '*** Can\'t rewrite "%s":' % self.filename, msg
+            return
+        print 'writing', self.filename
+        for line in self.lines:
+            fp.write(line)
+        fp.close()
+        self.changed = 0
+
+    def process(self, lineno, rest):
+        if self.lines is None:
+            print '(not processed): %s:%s:%s' % (
+                      self.filename, lineno, rest),
+            return
+        i = eval(lineno) - 1
+        if not 0 <= i < len(self.lines):
+            print '*** Line number out of range: %s:%s:%s' % (
+                      self.filename, lineno, rest),
+            return
+        if self.lines[i] == rest:
+            print '(no change): %s:%s:%s' % (
+                      self.filename, lineno, rest),
+            return
+        if not self.changed:
+            self.changed = 1
+        print '%sc%s' % (lineno, lineno)
+        print '<', self.lines[i],
+        print '---'
+        self.lines[i] = rest
+        print '>', self.lines[i],
+
+def main():
+    if sys.argv[1:]:
+        try:
+            fp = open(sys.argv[1], 'r')
+        except IOError, msg:
+            print 'Can\'t open "%s":' % sys.argv[1], msg
+            sys.exit(1)
+    else:
+        fp = sys.stdin
+    curfile = None
+    while 1:
+        line = fp.readline()
+        if not line:
+            if curfile: curfile.finish()
+            break
+        n = prog.match(line)
+        if n < 0:
+            print 'Funny line:', line,
+            continue
+        filename, lineno = prog.group(1, 2)
+        if not curfile or filename <> curfile.filename:
+            if curfile: curfile.finish()
+            curfile = FileObj(filename)
+        curfile.process(lineno, line[n:])
+
+if __name__ == "__main__":
+    main()
diff --git a/sys/src/cmd/python/Demo/scripts/wh.py b/sys/src/cmd/python/Demo/scripts/wh.py
new file mode 100755
index 000000000..b9b09efa6
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/wh.py
@@ -0,0 +1,2 @@
+# This is here so I can use 'wh' instead of 'which' in '~/bin/generic_python'
+import which