Euklas

Carnegie Mellon University has produced a tool called Euklas (Eclipse Users' Keystrokes Lessened by Attaching from Samples). From the description:

Euklas enhances Eclipse's JavaScript editor to help users to more successfully employ copy-and-paste strategies for reuse.

I think I'm going to cry.

Python: Enumerating IP Addresses on MacOS X

How do you enumerate the host's local IP addresses from python? This turns out to be a surprisingly common question. Unfortunately, there is no pretty answer; it depends on the host operating system. On Windows, you can wrap the IP Helper GetIpAddrTable using ctypes. On modern Linux, *BSD, or MacOS X systems, you can wrap getifaddrs(). Neither is trivial, though, so I'll save those for a future post.

Luckily, MacOS X provides a simpler way to get the local IP addresses: the system configuration dynamic store. Using pyObjC, which comes pre-installed on every Mac, we can write a straight port of Apple's example in Technical Note TN1145 for retrieving a list of all IPv4 addresses assigned to local interfaces:

from SystemConfiguration import *    # from pyObjC
import socket

def GetIPv4Addresses():
    """
    Get all IPv4 addresses assigned to local interfaces.
    Returns a generator object that produces information
    about each IPv4 address present at the time that the
    function was called.

    For each IPv4 address, the returned generator yields
    a tuple consisting of the interface name, address
    family (always socket.AF_INET), the IP address, and
    the netmask.  The tuple elements may also be accessed
    by the names: "ifname", "family", "address", and
    "netmask".
    """
    ds = SCDynamicStoreCreate(None, 'GetIPv4Addresses', None, None)
    # Get all keys matching pattern State:/Network/Service/[^/]+/IPv4
    pattern = SCDynamicStoreKeyCreateNetworkServiceEntity(None,
                                                          kSCDynamicStoreDomainState,
                                                          kSCCompAnyRegex,
                                                          kSCEntNetIPv4)
    patterns = CFArrayCreate(None, (pattern, ), 1, kCFTypeArrayCallBacks)
    valueDict = SCDynamicStoreCopyMultiple(ds, None, patterns)

    ipv4info = namedtuple('ipv4info', 'ifname family address netmask')

    for serviceDict in valueDict.values():
        ifname = serviceDict[u'InterfaceName']
        for address, netmask in zip(serviceDict[u'Addresses'], serviceDict[u'SubnetMasks']):
            yield ipv4info(ifname, socket.AF_INET, address, netmask)

One interesting point regarding this code is that it doesn't actually inspect interface information in the system configuration dynamic store. The interface-related keys are stored under State:/Network/Interface/, but this code (and Apple's example on which it is based) inspect keys under State:/Network/Service/ instead. However, if you want to get IPv6 addresses then you do have to inspect the system configuration's interface information:

from SystemConfiguration import *    # from pyObjC
import socket
import re
ifnameExtractor = re.compile(r'/Interface/([^/]+)/')

def GetIPv6Addresses():
    """
    Get all IPv6 addresses assigned to local interfaces.
    Returns a generator object that produces information
    about each IPv6 address present at the time that the
    function was called.
    
    For each IPv6 address, the returned generator yields
    a tuple consisting of the interface name, address
    family (always socket.AF_INET6), the IP address, and
    the prefix length.  The tuple elements may also be
    accessed by the names: "ifname", "family", "address",
    and "prefixlen".
    """
    ds = SCDynamicStoreCreate(None, 'GetIPv6Addresses', None, None)
    # Get all keys matching pattern State:/Network/Interface/[^/]+/IPv6
    pattern = SCDynamicStoreKeyCreateNetworkInterfaceEntity(None,
                                                          kSCDynamicStoreDomainState,
                                                          kSCCompAnyRegex,
                                                          kSCEntNetIPv6)
    patterns = CFArrayCreate(None, (pattern, ), 1, kCFTypeArrayCallBacks)
    valueDict = SCDynamicStoreCopyMultiple(ds, None, patterns)

    ipv6info = namedtuple('ipv6info', 'ifname family address prefixlen')

    for key, ifDict in valueDict.items():
        ifname = ifnameExtractor.search(key).group(1)
        for address, prefixlen in zip(ifDict[u'Addresses'], ifDict[u'PrefixLength']):
            yield ipv6info(ifname, socket.AF_INET6, address, prefixlen)

In fact, you could easily adapt the above function to be able to fetch IPv4 addresses from the interface configuration.

Caffeine Deficiency

My wife has been complaining that she always feels nauseous after taking her daily vitamin. On the theory that it was perhaps a result of taking them first thing in the morning on an empty stomach, she tried taking them at night with dinner. I saw with my own eyes what she was talking about: she almost vomited.

So, I told her to start taking mine instead and I'd finish her vitamins off. Well, I'm not doing that again. I don't know what it is about One A Day Women's Active Metabolism vitamins, but they made me sick too. While we hate wasting the money, we just chucked the rest of the bottle because there was no way either of us were ever taking those again. Before we tossed the bottle in the trash, though, we were examining the label for differences between her One A Day Women's Active Metabolism and my One A Day Men's vitamins that might account for the nausea. In particular, we were looking for ingredients that were in higher concentration in the women's vitamins.

There are a few: vitamins D, K, B1, B2, B6, Calcium, and Iron to be exact. But I couldn't find any hard evidence that any of these vitamins could cause the sort of nausea we experienced (at least not in quantities we are likely to be exposed to). But that is when we noticed what makes the women's vitamins earn the "active metabolism" moniker:


Caffeine, and lots of it. Guarana seed is just another source of caffeine, so it is possible that its 50mg is included in the total of 120mg of caffeine in each "vitamin" pill. But if not, that means that 1 One A Day Women's Active Metabolism pill has more caffeine (~170mg) than a cup of coffee (100-150mg) and approaching that of a single Vivarin pill (200mg).

While neither of us drinks much coffee and we try to avoid caffeinated drinks, I doubt that 170mg of coffee in the morning would be enough to induce nausea. After all, millions of people have a cup of coffee in the morning and that is approximately the same amount of caffeine.

But, we never expected to have caffeine added to vitamin pills. I guess that is what we get for not having looked at the label before buying them. We certainly won't be making that mistake again.

All that background out of the way, this experience got me thinking: just how much caffeine do people consume everyday now? Here my wife was getting a base 170mg a day without even knowing it. The marketing for caffeinated products tends to emphasize that it helps you stay "mentally aware"; how long before being constantly-caffeinated is considered the norm and the symptoms of caffeine deficiency are "mentally sluggish"?

At what point does caffeine go from "booster" to baseline? Is there a point in our future wherein caffeine belongs in vitamins and even has a FDA-recommended daily allowance?