Initial revision
diff --git a/Demo/scripts/makedir.py b/Demo/scripts/makedir.py
new file mode 100755
index 0000000..b08e455
--- /dev/null
+++ b/Demo/scripts/makedir.py
@@ -0,0 +1,20 @@
+#! /usr/local/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 not os.path.isdir(p):
+ head, tail = os.path.split(p)
+ makedirs(head)
+ os.mkdir(p, 0777)
+
+main()
diff --git a/Demo/scripts/mkrcs.py b/Demo/scripts/mkrcs.py
new file mode 100755
index 0000000..dc8dffb
--- /dev/null
+++ b/Demo/scripts/mkrcs.py
@@ -0,0 +1,61 @@
+#! /ufs/guido/bin/sgi/python
+#! /usr/local/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 `rcs`, 'is a symlink to', `os.readlink(rcs)`
+ return
+ if os.path.isdir(rcs):
+ print `rcs`, 'is an ordinary directory'
+ return
+ if os.path.exists(rcs):
+ print `rcs`, 'is a file?!?!'
+ 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 =', `p`
+ while not os.path.isdir(os.path.join(p, rcstree)):
+ head, tail = os.path.split(p)
+ #print 'head =', `head`, '; tail =', `tail`
+ if not tail:
+ print 'Sorry, no ancestor dir contains', `rcstree`
+ return
+ p = head
+ up = os.path.join(os.pardir, up)
+ down = os.path.join(tail, down)
+ #print 'p =', `p`, '; up =', `up`, '; down =', `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 `there`, 'already exists'
+ else:
+ print 'making', `there`
+ makedirs(there)
+ print 'making symlink', `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)
+
+main()
diff --git a/Demo/sockets/broadcast.py b/Demo/sockets/broadcast.py
new file mode 100755
index 0000000..9ed900f
--- /dev/null
+++ b/Demo/sockets/broadcast.py
@@ -0,0 +1,17 @@
+# Send UDP broadcast packets
+
+MYPORT = 50000
+
+import sys, time
+from socket import *
+
+s = socket(AF_INET, SOCK_DGRAM)
+s.bind('', 0)
+s.allowbroadcast(1)
+
+while 1:
+ data = `time.time()` + '\n'
+ s.sendto(data, ('<broadcast>', MYPORT))
+ time.sleep(2)
+
+
diff --git a/Demo/sockets/ftp.py b/Demo/sockets/ftp.py
new file mode 100755
index 0000000..ff15642
--- /dev/null
+++ b/Demo/sockets/ftp.py
@@ -0,0 +1,132 @@
+# A simple FTP client.
+#
+# The information to write this program was gathered from RFC 959,
+# but this is not a complete implementation! Yet it shows how a simple
+# FTP client can be built, and you are welcome to extend it to suit
+# it to your needs...
+
+
+import sys, posix, string
+from socket import *
+
+
+BUFSIZE = 1024
+
+# Default port numbers used by the FTP protocol.
+#
+FTP_PORT = 21
+FTP_DATA_PORT = FTP_PORT - 1
+
+# Change the data port to something not needing root permissions.
+#
+FTP_DATA_PORT = FTP_DATA_PORT + 50000
+
+
+# Main program (called at the end of this file).
+#
+def main():
+ hostname = sys.argv[1]
+ control(hostname)
+
+
+# Control process (user interface and user protocol interpreter).
+#
+def control(hostname):
+ #
+ # Create control connection
+ #
+ s = socket(AF_INET, SOCK_STREAM)
+ s.connect(hostname, FTP_PORT)
+ f = s.makefile('r') # Reading the replies is easier from a file...
+ #
+ # Control loop
+ #
+ r = None
+ while 1:
+ code = getreply(f)
+ if code in ('221', 'EOF'): break
+ if code == '150':
+ getdata(r)
+ code = getreply(f)
+ r = None
+ if not r:
+ r = newdataport(s, f)
+ cmd = getcommand()
+ if not cmd: break
+ s.send(cmd + '\r\n')
+
+
+# Create a new data port and send a PORT command to the server for it.
+# (Cycle through a number of ports to avoid problems with reusing
+# a port within a short time.)
+#
+cycle = [0]
+#
+def newdataport(s, f):
+ port = cycle[0]
+ cycle[0] = (port+1) % 16
+ port = port + FTP_DATA_PORT
+ r = socket(AF_INET, SOCK_STREAM)
+ r.bind(gethostbyname(gethostname()), port)
+ r.listen(0)
+ sendportcmd(s, f, port)
+ return r
+
+
+# Send an appropriate port command.
+#
+def sendportcmd(s, f, port):
+ hostname = gethostname()
+ hostaddr = gethostbyname(hostname)
+ hbytes = string.splitfields(hostaddr, '.')
+ pbytes = [`port/256`, `port%256`]
+ bytes = hbytes + pbytes
+ cmd = 'PORT ' + string.joinfields(bytes, ',')
+ s.send(cmd + '\r\n')
+ code = getreply(f)
+
+
+# Process an ftp reply and return the 3-digit reply code (as a string).
+# The reply should be a line of text starting with a 3-digit number.
+# If the 4th char is '-', it is a multi-line reply and is
+# terminate by a line starting with the same 3-digit number.
+# Any text while receiving the reply is echoed to the file.
+#
+def getreply(f):
+ line = f.readline()
+ if not line: return 'EOF'
+ print line,
+ code = line[:3]
+ if line[3:4] == '-':
+ while 1:
+ line = f.readline()
+ if not line: break # Really an error
+ print line,
+ if line[:3] == code: break
+ return code
+
+
+# Get the data from the data connection.
+#
+def getdata(r):
+ print '(accepting data connection)'
+ conn, host = r.accept()
+ print '(data connection accepted)'
+ while 1:
+ data = conn.recv(BUFSIZE)
+ if not data: break
+ sys.stdout.write(data)
+ print '(end of data connection)'
+
+# Get a command from the user.
+#
+def getcommand():
+ try:
+ return raw_input('ftp> ')
+ except EOFError:
+ return ''
+
+
+# Call the main program.
+#
+main()
diff --git a/Demo/sockets/radio.py b/Demo/sockets/radio.py
new file mode 100755
index 0000000..4bb55ff
--- /dev/null
+++ b/Demo/sockets/radio.py
@@ -0,0 +1,13 @@
+# Receive UDP packets transmitted by a broadcasting service
+
+MYPORT = 50000
+
+import sys
+from socket import *
+
+s = socket(AF_INET, SOCK_DGRAM)
+s.bind('', MYPORT)
+
+while 1:
+ data = s.recv(1500)
+ sys.stdout.write(data)