Archive for the ‘Uncategorized’ Category

2012w43

Sunday, October 28th, 2012

Idiocracy

No one can have missed the outrageous idiocracy in Italy which simply left me with a single question:
If they had warned, and panic had ensued, and people had gotten killed while trying to escape, and no quake would have hit… then what?… Seems like a case of “damned if you do, damned if you don’t”…

The US is implementing a “six strikes” type of deal (similar to the ?now defunct? French HADOPI) and apparently the “independent expert” used to draft a “reasonable” law might not have been so independent as they should have… being a former RIAA lobbying firm… The corruption surrounding the copyright industry is truly sickening.

I am probably waaaay to paranoid, but this reeks of false flag operation. Gotta keep the populus scared of them terrorists now don’t we?

Shut up and play nice: How the Western world is limiting free speech.

More and more I am beginning to think that the correct course of action is to completely boycott anyone who use the DMCA since it is used as a sledgehammer instead of a scalpel. I think this comment sums it up pretty well.

Surveillance / Privacy

Outsource government and corporate surveillance to people themselves… great…

Wait! Wait! Wait! You mean to say that geo-tagging can compromise ones privacy and security?!?! Nooo, who’d have thought?

Cool stuff

A distributed twitter thingy I think it’s cool and all, really cool, but I’d still go for identi.ca.

Sleipnir is a small proxy which you run, to intercept requests and serve local files instead. Not sure when or where I’d find use for it, but interesting concept none the less.

A rather good run-through of various tools for UNIX-like systems

Jeff Atwood wrote a post about the future of Markdown, and much have since been written and people have had opinions but from one of those discussions, what I found most interesting was Pandoc.

Stuff I learned

Great answer on how to better control node placement in a graphviz diagram.
And another answer on a similar question, although this should probably be considered an ugly-hack. Then again, there’s a time and place for everything.

Last week I prodded in some Perl code, and found myself unable to visualize just what the heck the internal structure of a variable looked like, and thought to myself Had this been PHP, I would have used var_dump(); I wonder if Perl have something similar?

Of course Perl has something similar.

use Data::Dumper;
print Dumper $my_mystery_var;

Source: Perl Mongers

Race-condition-free deployment with the “symlink replacement” trick

Food for thought

Why we can’t solve big problems.

Here’s a peculiar productivity hack: Hire a person to slap you in the face.

Compliance: The boring adult at the security party.

Why we buy into ideas: how to convince others of our thoughts

2012w09

Sunday, March 4th, 2012

Ohai!

This week has been rather productive. I’ve both gotten work done AND learnt a crapload of stuff AND gotten to hack away on some scripts, leading to some personal programming revelations :D

When it comes to shell scripting, printf has become a new friend (leaving echo pretty much out in the cold). It is a continuation from last weeks post about shell tricks and I actually got to use it helping a colleague at work to better format the output of a script.

Something along the lines of:

printf "There were %s connections from %s\n" `some-counting-command` $tmpIP

I also wrote a small demonstrator for another colleague:

for i in `seq 1 21`; do printf "obase=16; $i\n" | bc; done

(Yes, I know about printf’s ability to convert/print hexadecimal on the fly)

for i in `seq 1 21`; do printf "%0.2x\n" $i; done

The for loop piping to bc was mostly for fun and to spark ideas about loops and pipes.

In another script I found myself needing two things: a reliable way to shut the script down (it was running a loop which would only stop when certain things appeared in a log) and a way to debug certain parts of the loop.

I know there is nothing special at all about it, but coming up with the solution instead of trying to google myself to a solution left me feeling like a rocket-scientist ;D

If you have a loop, and you want the ability to controllably get out of said loop, do something along the lines of this in your script:

touch /tmp/someUniqueName
while [ ... && -f /tmp/someUniqueName ]; do 
    ...
done

My first thought was to use $$ or $! to have a unique name but since I wouldn’t (couldn’t) be running more than one instance of this script at a time, I didn’t need to worry about that, and it would have made it a tiny bit harder to stop the script, so I finally (thanks razor) opted for a static, known, filename.

While that file exists, and you other loop conditions are normal, the loop will … loop on, but the second either condition becomes false, like someone removing the file ;) the loop doesn’t do another iteration.

Problem two was that I wanted a quick way to switch between running the script live, or in debug mode. Since running it live calls on some other stuff which then takes a while to reset, debugging the script using these calls would have been painfully slow, but I found a neat way around that:

DEBUG="echo" # (should be "" (debug off) or "echo" (debug on)
...
$DEBUG some-slow-command
...

With debug “on” it will print the command and any parameters, instead of executing it. It doesn’t look all that impressive in this shortened example, but instead imagine if you had more than ten of those places you wanted to debug.

What would you rather do? Edit the code in ten+ places, perhaps missing one, or just change in one place, and have it applied in all the places at once?

This script, once in place and running, did however bring with it another effect, namely a whole lot of cleanup. Cleanup which could only be performed by running a command and giving it some parameters, which could be found in the output of yet another command.

To make matters worse, not all lines of that output were things I wanted to remove. The format of that output was along the lines of:

<headline1>,<date>
<subheader1-1>,<date>
<subheader1-2>,<date>
<subheader1-3>,<date>
<subheader1-4>,<date>
...

<headline2>,<date>
<subheader2-1>,<date>
<subheader2-2>,<date>
<subheader2-3>,<date>
<subheader2-4>,<date>
...

<headline3>,<date>
<subheader3-1>,<date>
<subheader3-2>,<date>
<subheader3-3>,<date>
<subheader3-4>,<date>
...

Again, these seem like small amounts, but for the “headline” I needed to clean up, there were about 70 subheaders, out of which I wanted to clean up all but one. Thankfully, that one subheader I wanted to preserve was not named in the same way as the other 69 subheaders (which had been created programmatically using the loop above).

Also, it was rather important not to delete any other headlines or subheaders. awk to the rescue! But first, here are some facts going into this problem:

  • the subheaders I wanted removed all shared a common part of name between each section is an empty line
  • I knew the name of the section heading containing the subheaders to remove
  • To remove one such subheader I’d need to execute a command giving the subheader as an argument

And this is what I did:

list-generating-command | awk -F, 
    '/headline2/ { m = 1 }
    /subheader/ && m == 1 { print $1 }
    /^$/ { m = 0 }' | while read name;
do
    delete-subheader-command $name
done

Basically, what is going on here is that first of all, setting the field separator to “,” and then, once we come across the unique headline string, set a little flag telling awk that we are within the matching area, and if it can only match the subheader pattern, it gets to print the first column of that line. Finally, when we reach any line containing nothing but a newline, unset the flag, so that there will be no more printouts

And another thing I’ve stumbled upon, and which I already know where I can use this, is this post and more specifically:

diff -u .bashrc <(ssh remote cat .bashrc)

(although it is not .bashrc files I am going to compare).

And finally, some links on assorted topics:

Vim and adding licenses to code

Thursday, March 31st, 2011

A while back @psquid gave me a new perspective on things.

I can’t remember what the discussion was about, but it left me with the realization that my current system (of having file type templates in vim coming with predefined licenses (GPL v3)) was flawed.

The thing I believe he got out of the discussion was that one could use snipMate to define ones own shortcuts for inserting licences into source code.

I couldn’t tell you why I hesitated so long before trying it, since the idea seemed sound. But when I did try it I came to two conclusions:

(1) It wouldn’t work the way I wanted it to , or (2) at least not without duplication.

Since I on occasion program both Python, Java, PHP, Bash and, infrequently, Erlang, in order to have licensing snippets (think GPL3, BSD, and the odd CC By-SA) I’d need to put these license-blurbs into each snippet file that should support it (since Python don’t do C-style comments, and Erlang-style comments are completely different as well)

So what I wanted was some way to call a Vim command (say NERD Commenter ( ,,cs )) once a certain snippet (the license blurb) had been expanded.

I am pretty sure this can’t be done in an easy way, so I gave that idea up. Mapping a key, say F3, to a user defined command in my .vimrc, however,  would be much easier.

Something along the lines of:

function! GPL3()
    r~/static/templates/gpl3
    :.,$call NERDComment(0, 'sexy')
endfunction
nmap  :call GPL3()

I am not well-versed at all with scripting vim, so I have probably made some embarrassing mistakes (for one, I should probably read up on what the heck that exclamation mark at the beginning of the function does. Please do point out any mistakes.)

All in all I am pretty content with this solution, but if someone know of a way to trigger a command after a snipMate expansion (and only on specific expansions, and only on the specific expanded lines) I am all ears.

(This since there is a _.snippet which seem to be included in all instances regardless of file type, which means I could still have the licenses in one place, defined once, but used with different comments anyway, which would be awesome) :)

:wq