Dieter on the web

Often while you're occupied with something, some thought pops into your head. Something that you want to remember/do something about.

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Phew! where to start? Probably at this blogpost. It's about making it very easy to work with external encrypted volumes. I'm not going to talk about the article itself but about a great tool i discovered thanks to it: Zenity. It's an LGPL-licensed program written in C by some guys from Gnome and Sun. You can call it from any script and present a user with a gtk widget such as a password-dialog, filechooser, calendar, ... It has

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PhpDeliciousClient is a console based client for doing maintenance on Del.icio.us accounts.
I wrote it because - to my knowledge - there currently is no good program (including the personalized del.icio.us web page itself) that lets you make changes to your del.icio.us data in a powerful, productive manner. (with data I primarily mean tags. Posts and bundles are considered less important).

You probably are familiar with the fact that a Delicious account (or any tag based meta data organizing system, for that matter) can soon become bloated: It gets filled with way too many tags. Among those tags several of them mean the same (fun, funny, humor, ...) or include the other (humor, jokes, ...) You can group them in bundles but even then you need to add all the tags to a post if you want it to appear in the results for that tag. Not very convenient. Also, if you have your del.icio.us bookmarks available in Firefox, you'd have a menu with several hundreds of entries (one for each tag), each menu containing usually just a few (or worse: just one) entry.

When I got in this situation I tried to fix it, but it was a hell of a task to do this on the Delicious webpage itself, and I although I found some other tools they were far to basic, outdated, dependent on other stuff or just not meant for this kind of task, so I decided to write my own.

The result is a php command line program called PhpDeliciousClient (as you can see, I added it to the menu on the left too), which uses the PhpDelicious library to access the Del.icio.us api.

The primary focus of the program is to help you to bring your tags in balance, in an as efficient way as possible. Other stuff, which can be done just fine on the delicious page (editing single posts, changing your password, ...) is not implemented.

It's a bit hacky, I don't give any guarantees but I can tell I used it to edit my own Del.icio.us page, going from about 400 tags to about 80 without any problems.

That said, head over to the PhpDeliciousClient project page for some more information, and to download it ;-)

== A library providing UI functions for shell scripts ==

When you write bash/shell scripts, do you write your own error/debug/logging/abort functions?
Logic that requests the user to input a boolean, string, password, selection out of a list,
date/time, integer, ... ?

Libui-sh is written to take care of all that.
libui-sh is meant to a be a general-purpose UI abstraction library for shell scripts.
Low impact, easy to use, but still flexible.
cli by default, can optionally use ncurses dialogs as well.


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Put this in your .bashrc, and the current directory in your PS1 will be printed green if the previous command had exit state 0, red otherwise. No more typing 'echo $?', ' && echo ok', '|| echo failed' etc on the command line.

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Ever needed to use arrays of two or more dimensions but got stuck on Bash limited array support which provides only 1 dimension?

There is a trick that let's you dynamically create variable names. Using this, you can emulate additional dimensions.


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UPDATE: this information is outdated. See http://github.com/Dieterbe/ddm/tree/master for latest information.

Introduction

If you have multiple sets of data (e.g.: music, images, documents, movies, ...) and you use these on more then one system ( e.g. a laptop and a file server) then you probably also have some 'rules' on how you use these on your systems. For example after capturing new images you maybe put them on your laptop first but you like to sync them to your file server frequently. On the other hand you also want all your high-res images (stored on the server) available for editing on the laptop, and to make it more complicated you might have the same images in a smaller format on your server (for gallery programs etc.) and want these (or a select few albums of them) available on the road.

The more different types of data you have and the more you have specific work flows the harder it becomes to keep your data as up to date as possible and consistent on your boxes. You could manually rsync/(s)cp your data but you end up in having a mess (at least that's how it turned out on my boxes). Putting everything under version control is great for text files and such, but it's not an option for bigger (binary) files.

I wanted to keep all my stuff neatly organised in my home directories and I want to create good work flows with as minimum hassle as possible, so I decided to write DDM: the Distributed Data Manager.

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DDM v0.4 has been released.
Since the last release many, many things have been changed/fixed/added.


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FOSS is written by users, for users, and what I've been doing/experiencing this afternoon is a perfect example of that.

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In light of the work and discussions around supporting Nilfs2 and Btrfs on Arch Linux and its installer AIF,
I've shared some AIF filesystem code design insights and experiences on the arch-releng mailing list.
This is some hard to understand code. Partly because it's in bash (and I've needed to work around some limitations in bash),
partly because there is some complex logic going on.

I think it's very useful material for those who are interested (it can also help understanding the user aspect),
so I wanted to share an improved version here.
On a related topic: I proposed to do a session at Fosdem 2011/"distro miniconf" about simple (console based) installers for Linux,
and how multiple distributions could share efforts maintaining installation tools, because there are a lot of cross-distribution concerns
which are not trivial to get right (mostly filesystems, but I also think about clock adjustments, bootloaders, etc).
Already several distro's use the (or a fork of) the Arch installer, for example Pentoo,
but I think cooperation could be much better and more efficient.

Anyway:


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I've been thinking about how a specific bash history for each directory could improve productivity, and unlike what I feared it was actually pretty easy to find a solution on the net.

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Every year, during a special weekend in February, the University Libre of Brussels suddenly becomes a little more geeky.
It's that time of the year when many European (and some inter-continental) colleagues join us at
Fosdem: the Free and Open source Software Developers' European Meeting (more info here).

Fbcmd is pretty cool.
I quickly hacked this script together which pulls all photo albums from friends on facebook, so I have them available where I want. (It should also pull your own albums, but I don't have any so I can't check that)

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Hello everyone.
This post is about bash, the shell providing so many users easy access to the underlying power of their system.
(not bash the quote database, although i really like that website too ;-) )
Most people know the basics, but getting to know it better can really increase your productivity. And when that happens, you might start loving bash as much as I do ;-)

I assume you have a basic knowledge of bash, the history mechanism, and ~/.bash* files.
So here they are, my favorite tricks, key combo's and some bonus stuff:

Tricks

• "cd -" takes you back to the previous directory, wherever that was. Press again to cycle back.
• putting arguments between braces {like,so} will execute the command multiple times, once for each "argument". Bash will make the cartesian product when doing it multiple times in 1 expression. Some less-obvious tricks with this method are mentioned here
• HISTIGNORE : with this variable you have control over which things are being saved in your history. Here is a nice explication. Especially the space trick is very useful imho.
• CD_PATH : Here is a great explanation ;-)
• readline (library used by bash) trick: put this in your ~/.inputrc (or /etc/inputrc) :
  

  "\e[5~": history-search-backward
  "\e[6~": history-search-forward
  

  This way you can do *something*+pageup/pagedown to cycle through your history for commands starting with *something*
  You can use the up/down arrows too, their codes are "\e[A" and "\e[B"

• for more "natural" history saving behavior (when having several terminals open): put this in .bash_profile:
  
  

  PROMPT_COMMAND='history -a'
  

  (write each command separately in a new entry, instead of all at shell exit).
  And type

  shopt -s histappend
  

  to append instead of overwrite. (this might be default on some distro's. I think it was on Gentoo)

Shortcuts/keycombos

• ctrl+r : search through your history. Repeatedly press ctrl+r to cycle through hits.
• ctrl-u : cut everything on the current line before the cursor.
• ctrl-y : paste text that was cut using ctrl-u. (starting at the cursor)
• !$: equals the last word of the previous command. (great when performing several operations on the same file)

Bonus material

• Bash completion, an add-on for bash which adds completion for arguments of your commands. It's pretty smart and configurable. (it's in portage, and probably in repos of all popular distros out there)
• This script provides you an interface to the rafb pastebin!
• Recursively delete all .svn folders in this folder, and in folders below. "find . -name .svn -print0 | xargs -0 rm -rf"
• Recursively count number of files in a directory: "find -not -type d | wc -l"

Conclusion

Those were all important tricks I'm currently using. On the web you'll find lots more useful tips :-).
If that still isn't enough, there is also man bash :o

With aliases and scripts (and involving tools like sed or awk) the possibilities become pretty much endless. But for that I refer to tldp.org and your favorite web search engine.