Even though bash is not my favorite programming language, I end up writing a bit of code in it. It's just super practical to have something in bash if you can. I mentioned in the past how it's a good idea to avoid unnecessary cpu/io while initializing the shell by doing deferred aliasing. That solves the alias problem, but I also have a bunch of bash code in terms of functions. So I was thinking the same principle could be applied again.

Let's use findpkgs as an example here. The function is defined in a separate file and the file is source'd. But this means that every time I start a new shell session the whole function has to be read and loaded into memory. That might not be convenient if there are a number of those. networktest, for instance, defines four function and is considerably longer.

So let's "compile to bytecode" again:

findpkgs ()
{
    [ -f ~/.myshell/findpkgs.sh ] && . ~/.myshell/findpkgs.sh;
    findpkgs $@
}

When the function is defined this way, the script actually hasn't been sourced yet (and that's precisely the idea), but it will be the minute we call the function. This, naturally, will rebind the name findpkgs, and then we call the function again, with the given arguments, but this time giving them to the actual function.

Okay, so that was easy. But what if you have a bunch of functions loaded like that? It's gonna be kinda messy copy-pasting that boilerplate code over and over. So let's not write that code, let's generate it:

lazyimport() {
# generate code for lazy import of function
	function="$1";shift;
	script="$1";shift;

	dec="$function() {
		[ -f ~/.myshell/$script.sh ] && . ~/.myshell/$script.sh
		$function \$@
	}"
	eval "$dec"
}

Don't worry, it's the same thing as before, just wrapped in quotes. And now we may import all the functions we want in the namespace by calling this import function with the name of the function we want to "byte compile" and the script where it is found:

## findpkgs.sh

lazyimport findpkgs findpkgs

## networktest.sh

lazyimport havenet networktest
lazyimport haveinet networktest
lazyimport wifi networktest
lazyimport wifiscan networktest

## servalive.sh

lazyimport servalive servalive

So let's imagine a hypothetical execution. It goes like this:

1. Start a new bash shell.
2. Source import.sh where all this code is.
3. On each call to lazyimport a function declaration is generated, and eval'd. The function we want is now bound to its name in the shell.
4. On the first call to the function, the generated code for the function is executed, which actually sources the script, which rebinds the name of the function to the actual code that belongs to it.
5. The function is executed with arguments.
6. On subsequent executions the function is already "compiled", ie. bound to its proper code.

So what happens, you may wonder, in cases like the above with networktest, where several mock functions are generated, all of which will source the same script? Well nothing, whichever of them is called first will source the script and overwrite all the bindings, remember? It only takes one call to whichever function and all of them become rebound to the real thing. So all is well. :)

Amazement is something for a special occasion. It is supposed to be rare. It is supposed to be worth a story. It is not for everyday use.

I amaze so easily, and so frequently, that amazement has ceased to be special to me. It has become mundane. I need to check my standards for amazement. I need to raise the bar. I need to make amazement once again worth having.

I must stop being amazed, for example, when a man rings my doorbell because he cannot figure out the house numbers on my street. "Is this number thirty", he asks. I lean out, in a mock gesture, to gaze at the street number opposite my front door. It does not say thirty. I imagine this gesture will suffice to make him understand. Instead he reiterates his dilemma. "Is this number thirty." No. It is not. I must not be amazed, even if it is a man in his fifties. With gray hair, an elegant tie, and a fancy suit. Who proceeds to reenter his expensive automobile. How does a person like that not know how to read street numbers. I must not be amazed.

I must not be amazed, either, at the communal workers. Who must necessarily have intimate knowledge of such complicated administrative intricacies as are street numbers. Through their work of visiting various addresses everyday. Who still ring my doorbell by mistake.

One wonders how such people can accomplish complicated tasks like air travel, which requires all sorts of documents, procedures, requires remembering important facts and following a timetable. How do they manage it? It seems amaz I'm sure they pull it off somehow.

It seems to me that we have pretty good tools for managing files that aren't changing. We have file managers that display all the pertinent details, they'll detect the file type, they'll even show a preview if the content is an image or a video.

But what about files that are changing? Files get transfered all the time, but network connections are not always reliable. Have you ever been in the middle of a transfer wondering if it just stopped dead, wondering if it's crawling along very slowly, too slow, almost, to notice? Or how about downloading something where the host doesn't transmit the size of the file, so you're just downloading not knowing how much there is left?

These things happen, not everyday, but from time to time they do. And it's annoying. A file manager doesn't really do a great job of showing you what's happening. Of course you can stare at the directory and reload the display to see if the file size is changing. (Or the time stamp? But that's not very convenient to check against the current time to measure how long it was since the last change.) Or maybe the file manager displays those updates dynamically? But it's still somewhat lacking.

Basically, what you want to know is:

1. Is the file being written to right now?
2. How long since the last modification?

And you want those on a second-by-second basis, ideally. Something like this perhaps?

Here you have the files in this directory sorted by modification time (mtime). One file is actively being written to, you can see the last mtime was 0 seconds ago at the time of the last sampling. Sampling happens every second, so in that interval 133kb were written to the file and the mtime was updated. The other file has not been changed for the last 7 minutes.

The nice thing about this display is that whether you run the monitor while the file is being transfered or you start it after it's already finished, you see what is happening, and if nothing is, you see when the last action took place.

#!/usr/bin/env python
#
# Author: Martin Matusiak <numerodix@gmail.com>
# Licensed under the GNU Public License, version 3.
#
# <desc> Watch directory for changes to files being written </desc>

import os
import sys
import time


class Formatter(object):
    size_units = [' b', 'kb', 'mb', 'gb', 'tb', 'pb', 'eb', 'zb', 'yb']
    time_units = ['sec', 'min', 'hou', 'day', 'mon', 'yea']

    @classmethod
    def simplify_time(cls, tm):
        unit = 0
        if tm > 59:
            unit += 1
            tm = float(tm) / 60
            if tm > 59:
                unit += 1
                tm = float(tm) / 60
                if tm > 23:
                    unit += 1
                    tm = float(tm) / 24
                    if tm > 29:
                        unit += 1
                        tm = float(tm) / 30
                        if tm > 11:
                            unit += 1
                            tm = float(tm) / 12
        return int(round(tm)), cls.time_units[unit]

    @classmethod
    def simplify_filesize(cls, size):
        unit = 0
        while size > 1023:
            unit += 1
            size = float(size) / 1024
        return int(round(size)), cls.size_units[unit]

    @classmethod
    def mtime(cls, reftime, mtime):
        delta = int(reftime - mtime)
        tm, unit = cls.simplify_time(delta)
        delta_s = "%s%s" % (tm, unit)
        return delta_s

    @classmethod
    def filesize(cls, size):
        size, unit = cls.simplify_filesize(size)
        size_s = "%s%s" % (size, unit)
        return size_s

    @classmethod
    def filesizedelta(cls, size):
        size, unit = cls.simplify_filesize(size)
        sign = size > 0 and "+" or ""
        size_s = "%s%s%s" % (sign, size, unit)
        return size_s

    @classmethod
    def bold(cls, s):
        """Display in bold"""
        term = os.environ.get("TERM")
        if term and term != "dumb":
            return "\033[1m%s\033[0m" % s
        return s

class File(object):
    sample_limit = 60  # don't hold more than x samples

    def __init__(self, file):
        self.file = file
        self.mtimes = []

    def get_name(self):
        return self.file

    def get_last_mtime(self):
        tm, sz = self.mtimes[-1]
        return tm

    def get_last_size(self):
        tm, sz = self.mtimes[-1]
        return sz

    def get_last_delta(self):
        size_last = self.get_last_size()
        try:
            mtime_beforelast, size_beforelast = self.mtimes[-2]
            return size_last - size_beforelast
        except IndexError:
            return 0

    def prune_samples(self):
        """Remove samples older than x samples back"""
        if len(self.mtimes) % self.sample_limit == 0:
            self.mtimes = self.mtimes[-self.sample_limit:]

    def sample(self, mtime, size):
        """Sample file status"""
        # Don't keep too many samples
        self.prune_samples()
        # Update time and size
        self.mtimes.append((mtime, size))

class Directory(object):
    def __init__(self, path):
        self.path = path
        self.files = {}

    def prune_files(self):
        """Remove indexed files no longer on disk (by deletion/rename)"""
        for f in self.files.values():
            name = f.get_name()
            file = os.path.join(self.path, name)
            if not os.path.exists(file):
                del(self.files[name])

    def scan_files(self):
        # remove duds first
        self.prune_files()
        # find items, grab only files
        items = os.listdir(self.path)
        items = filter(lambda f: os.path.isfile(os.path.join(self.path, f)),
                       items)
        # stat files, building/updating index
        for f in items:
            st = os.stat(os.path.join(self.path, f))
            if not self.files.get(f):
                self.files[f] = File(f)
            self.files[f].sample(st.st_mtime, st.st_size)

    def display_line(self, name, time_now, tm, size, sizedelta):
        time_fmt = Formatter.mtime(time_now, tm)
        size_fmt = Formatter.filesize(size)
        sizedelta_fmt = Formatter.filesizedelta(sizedelta)
        line = "%6.6s   %5.5s   %6.6s   %s" % (time_fmt, size_fmt,
                                               sizedelta_fmt, name)
        if time_now - tm < 6:
            line = Formatter.bold(line)
        return line

    def sort_by_name(self, files):
        return sorted(self.files.values(), key=lambda x: x.get_name())

    def sort_by_mtime(self, files):
        return sorted(self.files.values(),
                      key=lambda x: (x.get_last_mtime(),x.get_name()))

    def display(self):
        time_now = time.time()
        files = self.sort_by_mtime(self.files.values())
        print("\nmtime>   size>   delta>   name>")
        for f in files:
            line = self.display_line(f.get_name(),
                                     time_now, f.get_last_mtime(),
                                     f.get_last_size(), f.get_last_delta())
            print(line)


def main(path):
    directory = Directory(path)
    while True:
        try:
            directory.scan_files()
            directory.display()
            time.sleep(1)
        except KeyboardInterrupt:
            print("\rUser terminated")
            return


if __name__ == '__main__':
    try:
        path = sys.argv[1]
    except IndexError:
        print("Usage:  %s /path" % sys.argv[0])
        sys.exit(1)
    main(path)

There was a movement within the Norwegian education system at one point to emphasize the goal that kids in school should be critical. More than that, it should be the goal of the education system to teach us to be read critically. Don't take everything you hear as gospel. This was back when I was still in junior high, so a good 15 years back. I don't know if this theme is still current today, but at the very least it made a good pass through the common consciousness at one point.

So why did this come about? Well, in the early 90s television was privatized. There had been cable tv for a number of years already, but in 1992 the channel TV2, the first commercial tv station to broadcast nationally, alongside the state broadcaster NRK, was launched. Effectively, television was let go from under the control of the rather insular NRK and freed to be driven by commercial profit. Naturally, TV2 in short order proceeded to import all of the popular culture, chiefly American, that has informed our lives. Another characteristic of TV2, quite unlike NRK -- the absolute sterility of any form of even mild intellectualism. (Aside from NRK which may have as much as 2-3 weekly hours of programming suited to the more discerning viewer, provided the topic is up your street.)

Another big development in the mid and late 90s, of course -- wide access to the internet. Here again is a brand new medium with immense amounts of information and culture "beamed" right into our homes.

I feel it was these two developments that formed the impetus behind this fashion within the education system. All of a sudden students would be writing essays using web pages for sources that, believe it or not, were just incorrect. :eek: Oh noes, something has to be done! And so it began. The internet is not trustworthy. You can't believe everything you read. The deeper reasoning behind this is the question of motive. More important than what they are saying; why are they saying it? Back in my junior high days we received the dumbed down version (as, actually, with everything in junior high). The question was framed in terms of sources. This source is reliable, because it's Encyclopedia Britannica. This source is not, because it's a web page, or I heard it on tv. Never mind who gets to decide what is reliable and why.

Of course, the truth, as your astute self would have figured out by now, is that nothing is in and of itself trustworthy. It's not just when you go online that you find garbage. There's just as much garbage in books, in what your teachers tell you, in what your parents tell you, and above all in what your peers tell you. You need to be critical of all this stuff, not just of those crazy people on the internet.

I'm inadvertently rehashing Jürgen's argument here. I read his entry and didn't give it any more thought, but perhaps my subconsciousness has been chewing on it ever since? Thanks, Jürgen.

Naturally, some people are just malicious, but that is not the main problem. Even if you do have a piece of insight that you honestly believe is beneficial to someone, there are still a lot of things that can go wrong:

1. You're plain mistaken.
2. It works for you, but it doesn't work for everyone.
3. Even though you have the right idea, you fail to communicate it effectively.

The last one is particularly unfortunate. How many times has someone told you that they've just this discovered this new thing and it's everything they needed, and then you say "but I told you that already a long time ago!". Well, I guess you didn't tell me in the words that I needed to hear in order to absorb the information, or in order to be convinced.

Parental advice, of course, is susceptible to the same flaw as those self help books. I'm sure you've seen some of those around, the basic premise is always the same -- some person has figured out how to do something and wants to tell everyone. The problem is that just because it worked for him, doesn't mean it will work for you. Especially when you hear it from a secondary source (a relative comes up and says "I read this amazing book, it changed my life, all you have to do is.."). But it's not science. At best it "sorta works a lot of the time, kind of".

So over time you develop a filter. "This person is not worth listening to on these topics, this book is written by someone who has no idea what he's talking about, this website is usually reliable on these issues". Now everything depends on that filter of yours. You may find one day that you bought into some utter nonsense, or that you discarded good insight.

One of the most important currencies of today is time. Of course, people have always been trading in time, paying people to do things for them that they were either too lazy, or "too important", to do. But in today's world time has gone as far as to replace money in the daily rhetoric of many people. I wonder if people in the past spent as much time complaining about not having enough time as it's common to do today. We have more freedoms and opportunities than ever, there's just no time to enjoy them all.

The biggest complaint among people today, once they stop complaining about lack of money, is lack of time. There is a strange kind of contempt for people who have time.
- Look at this cool thing these guys did.
- Yeah they really have a lot of time on their hands (those rich bastards!)

Strangely enough, there are also those who have a sense of pride about *not* having time. They just love fake-complaining to you about how busy they are. Well who decided you have to be so busy? Oh, I know, *you* did. Here, I have the solution for you. Ditch _everything_ that you're doing right now and you'll have more time than you ever dreamed of.

Being busy is also the standard way to lie to yourself when rejecting people. "Oh dear, I'd love to come to your whatever, but I'm just so darn busy". No, you just decided that you'd rather do something else. *I* know what it means, and you might as well just have told me that you weren't interested instead of telling yourself that you're a caring person who never lets anyone down. Because that's just plain obnoxious.

Now, what people seem to forget is that unlike money, time is very much your own choice. You don't choose to be born into a wealthy family, but you can easily choose to be rich on time. Here's a simple test: do you have a tv? Unplug it. You just won hours upon hours of time and it didn't cost you a dime! (Unless of course tv is what you most want to use your time for, but then you shouldn't complain about lack of time, you should revel in all the tv time you have!)