Archive for the ‘’ Category

music management

Tuesday, March 6th, 2007

After making the switch to linux full-time, I needed an easy way to convert my old music collection to mp3s. Yes, yes… there are the DRM’d files from my purchases on iTunes, and I won’t go into converting them. Otherwise, I had some files in mp3, and quite a large amount in m4a. It’s fairly easy to do the conversion in linux, but it can get tedious if your library is huge. Here’s a little shell script I wrote to parse a given directory and convert mp4s easily. I hope it’ll be useful to someone!

You’ll need faad and lame installed, natch.


#!/bin/bash

find /media/music -name '*.m4a' -print0 | xargs -0 -I {} bash -c 'FILE=`(echo "{}" | sed -e "s/.m4a//g")`; faad "$FILE.m4a"; lame -h -b 192 "$FILE.wav" "$FILE.mp3"; rm -f "$FILE.wav"'

exit 0

the wonders of vi(m)

Saturday, January 20th, 2007

Ever since I started using Linux, which at this point was about 10 years ago, I’ve used the Vi editor. It was included as the default editor for most distributions back then, and it was really all that I was accustomed to. The usually cryptic commands make it pretty difficult to pick up, and I think that difficulty is why many people dismiss it so much. If you give it a try though, you’d be surprised at what you can do with it.

An article recently at The Register gave some interesting background. Essentially, Vi was made to be usable over a 300 baud modem. At that speed, even small commands are burdensome to type, and screen painting is horrendous. So the small, one-letter commands in Vi had a specific purpose – speed and efficiency.

So that begs the question: In the age of high resolution and broadband, why would anyone in their right mind still use an editor from 1976? The answer, to be honest, isn’t an easy one. Like I said, I personally started using Vi when I didn’t know of any other choice. I learned three commands… ‘a’, ‘:q’, and ‘:wq’, and that was good enough for me. Those commands allowed me to edit any file I needed to edit on my Linux boxes, and I could do it quickly. As any Vi user will attest, once you learn the very basic commands, you find yourself using them everywhere, even when you’re not using Vi. I think it’s because they are SO easy to use, they just make sense.

At this point, I suppose I should start saying ‘Vim’, for fairness. Vim was created to give a user the power of Vi, but extend it to add many cool features. The abilities of Vim are a surprisingly long list. Most anything you can think of, Vim can manage it, and it still remains a text-based editor. A GUI exists for it, sure, but I honestly know no one who actually uses it. :)

These days, I’ve had the wonderful chance to use Vim in my every day work, and I must say, I love it. I keep 3-4 xterms open all day long, and Vim runs on all of them. Something I’ve noticed is that like Linux itself, using Vim every day allows you to learn some incredibly useful shortcuts that you may never have seen. That’s my reason for writing this article… to educate those Vi users who only know the most basic commands, and to also help cement some of the useful shortcuts in my brain.

First, my (most recent) .vimrc file:
[php]
:colors slate
:hi Normal guifg=white guibg=black
:hi Search guibg=#224488
:hi Visual guibg=#111144
:hi DiffAdd guibg=#003311
:hi DiffChange guibg=#222222
:hi DiffDelete guibg=#110000
:hi DiffText guibg=#AA1100
:set guifont=Bitstream\ Vera\ Sans\ Mono\ 7.5
:set guioptions-=m
:set guioptions-=l
:set guioptions-=L
:set guioptions-=r
:set guioptions-=R
:set guioptions-=T
:set softtabstop=2
:set tabstop=2
:set mouse=a
:set number
:set expandtab
:set shiftwidth=2
:map :noh
:map :tabnew
:imap :tabnew
:nmap :tabnew
:vmap >gv
:vmap :vmap zf :set foldcolumn=5
:nmap zo
:nmap zc
:nmap :set foldcolumn=0
:map :noh
:map :s/^/\/\//:noh
:map :s/^\/\///:noh
:map :vert diffsplit =expand(“%:h”)/.svn/text-base/=expand(“%:t”).svn-base
:map :q:diffoff
:map :syntax match Character “\|”
[/php]

So some very useful things any newbie should know…

The ‘/’ character, in command mode, starts a search. This search accepts regex, and can be global or one line. So the simplest use is to simply type ‘/something’. That command highlights every instance of the word ‘something’ in the file. While still in command mode, typing ‘n’ will go to the next search result. Quick and painless, right?

The search and replace syntax is pretty standard. The replace the abbreviation ‘NY’ with ‘New York’, simply type ‘:s/NY/New York/g’. That will replace it on the current line only. The expand it to the entire file, just add a ‘%’ in front of the s: ‘%s/NY/New York/g’. Pretty simple, eh?

Here’s something that’s cool… split screen editing of the same file. Hit ‘Ctrl-w s’ and you’ll now have two copies of the current file on the screen. Do it again, and you’ll have three. ‘Ctrl-w c’ closes the current split. If you use the ‘mouse=a’ setting, clicking will switch between the different sections. Otherwise ‘Ctrl-w uparrow/downarrow’ will do it. There’s a surprising lack of split-file editing capabilities in editors these days. Enjoy it!

Did you know about Visual mode? Hit ‘v’ in command mode and use the arrows to highlight lines. You can then use ‘d’ for delete (like the ‘cut’ command), ‘y’ to yank (like the ‘copy’ command), and ‘p’ to paste. If you have the ‘mouse=a’ setting enabled, click-drag will automatically enter Visual mode. So it’s a quick clickdrag-y-click-p to copy and paste text between two places in the file. While you’re at it, highlighting a chunk of text in Visual mode and hitting ‘<' and '>‘ will tab/untab the block. 2007-02-02 – You can also hit a number before you hit ‘<' or '>‘ to tab that number of times.

One thing I like to do is store commonly used methods in regular text files. If I need those methods, I can insert them directly into the current document with ‘:r filename’. That reads the entire file in and places it wherever your cursor was located in the file.

If you don’t like the default colors that Vim uses, you can modify them. Take a look in /usr/share/vim/vim70/colors. Those are the default color schemes that come with Vim, and you can use them with the command ‘:colors [colorfile]’. You can also just use them as a starting point and include custom color commands in your .vimrc file.

I know there are more things that I do in Vim that I can’t think of right now, so I’ll come back and update this article now and then. I hope at least one or two of these functions were unknown when you started reading. If you’re a Vim master and you’ve read this fafr, what are your favorite features? Please leave a comment!

Added: 2007-01-22

“$” means ‘end’. It can mean the end of the line, or the end of the file. Typing “:$” goes directly to the last line. And on the subject of moving around in the file, use ‘:’ and the line number to warp directly to a specific line.

Added: 2007-02-03

So recently I’ve started using (gasp!) Gvim, the ‘GUI’ for Vim. The thing that sold me on it wasn’t so much the GUI features (I’ve disabled them all) but the font rendering features. For one, you can use true-type fonts, rather than being stuck with the one in xterm. The other thing though, is that it does AA on the fonts, which means dot values! So I’m now using Bitstream Vera Sans Mono 7.5. It doesn’t seem like much, but try that in an xterm! :)

While I’m here, I’ve started using yet another feature. While in insert mode, with mouse=a enabled, double-click on a word. It enters visual mode and highlights the word. Now hit ‘d’ for delete, and it deletes the word and returns to insert mode.

Also, instead of using the method I detailed above for split-screen editing, I’ve started using :split and :vsplit. This allows you to split the current screen up quite a lot. Then, while in one of the split frames, type ‘:e path/to/file’ and you now have multiple files open in the same window. That was HUGE to me! And since they’re all within the same session of Vim, the copy/paste buffer will go between all of the files. That rids me of the need for the mouse=c functionality. Woo!

Added: 2007-02-13

It’s funny how your methods change over time. The amazing thing is how often I find new ways of doing something in Vim. I explained somewhere above how to use Visual mode. Basically, if you have mouse=a set, you can just highlight characters and you’ll automatically be in Visual. Here’s something cool though: try moving your cursor to the middle of a line and hit Ctrl-v, then use the down arrow. You’ll notice that instead of highlighting the entire line, it allows you to highlight a certain character region on your screen. This is Visual Block mode. Imagine if you had two columns of text and you wanted to move the second column a couple of tab stops over… Just put your cursor at the beginning of the column you want to move, Ctrl-v, down arrow to the end of the column, and then hit ‘>’. Neat, eh?

Sometimes you need to replace characters in a certain chunk of code, but not the whole document. Using either Visual or Visual Block mode, highlight the area you want the ‘replace’ to affect. Then you modify the normal pattern “:%s/something/something else/g”, adding “\%V”. So to replace ‘Yay’ with ‘w00t’ in a Visual area, you’d use “:%s/\%VYay/w00t/g”. Easy as Pi. ;)

moving to another city, and gentoo

Saturday, January 13th, 2007

I’ve moved! I’m now in the amazing city of Austin, TX and into an equally amazing job. I love it, and the people I work with! One of the things I needed to get used to at the new place was using Gentoo on the desktop. Up until then, I had mainly standardized on Ubuntu in various flavors. I love the ease of use, and I love how… well… pretty it is. But coming from both camps, I wanted to give a basic breakdown of the differences, and why you might want to give Gentoo a try yourself.

The biggest difference between Gentoo and most other distributions is that every package installed in your system is compiled from scratch. There are benefits on both sides of the argument. In a binary distribution, the speed of installing apps is just amazing. Using apt is just… wonderful. The problems come in when you want to install an application that isn’t in the apt repository, or when the version you want to install is much newer than the one in apt. At this point, your choices include either waiting a while (possibly a long time) for the version to get updated, or compiling your own. Simple enough, but what happens when you go to install an application that depends on the one you compiled? Apt doesn’t see the compiled version in it’s internal database, so it tries to install it’s own. So your choice there is to install the other application from source as well. Don’t get me wrong, apt is awesome. It’s just that in certain instances, it would be nice to have a little more control.

In addition, think about compiling. Every application you compile has certain flags that enable different functionality. It might be a choice between using ALSA or OSS, or whether to let the app have SVG support… there are a million things. Well, in order to be all things to all people, the application in the apt repositories are compiled to work with pretty much everything. The side-effect of that is a potential for slowdowns. When you think about it, it only makes sense that the more you allow your program to do, the more CPU cycles it will take in running. And while one itsy bitsy flag enabling some random feature might not make a huge diff, what about scaling that across an entire operating system? If you have ever compiled your own kernel, it’s the same reason you don’t compile in every feature possible… you pick and choose for the most efficiency.

So those are the main reasons why I’m quickly becoming a Gentoo fan. I love Ubuntu for people who are new to Linux, but for those of us that know (or at least should know) a little more about our OS, Gentoo is a great fit.

Gentoo’s package management system is called Portage. It consists of what are called ‘ebuilds’, which are basically just scripts that tell the Portage system how to compile a given application. So for every application that is available, there’s an ebuild for it in the Portage tree. But there’s more! Remember the version issues you run into with binary package managers? There are ebuilds available for many of the latest builds of various software, and nearly every version number in between. So by changing a few configs, you can install an older more stable version, or you can allow Portage to see and install some pretty bleeding-edge stuff. Not only that, but there are some builds that actually use CVS to bring down the absolute latest version, and compile it automatically.

It’s hard to complain about the selection of software available on Gentoo through Portage. It’s got pretty much everything and the kitchen sink available for installation. And the great thing is, like all package managers, it understands interaction between different software. That means if you go to install WhizBang package, and WhizBang requires the SupaSecret KungFoo package, Portage will compile SupaSecret first, and then compile WhizBang. Not only that, but there’s even a program that will rebuild all of your dependencies, throughout the system, in case one gets hosed.

Binary package managers have methods (sometimes) for upgrading the system to the newest release. With Gentoo, the entire system is in a sort of continuous development. That means that there’s no specific ‘version’ of Gentoo… you install it, and then compile the packages (whatever the newest versions are) that you want. It’s very customized. That means that it’s very easy to bring your system up to date… “emerge –sync && emerge -update -deep world” will go through and find everything in your system that’s out of date, and update those packages. Swanky.

In all fairness, the advantages DO come with a price. The main thing that people complain about with Gentoo is the time that it takes to compile. For example, I installed it for the first time by myself on my laptop. It’s an AMD64 3200+ system, and it took slightly over 15 hours of compiling before the system was really at a usable state. By usable, I include compiling X, Gnome, the KDE libraries, WiFi drivers, and the various software I normally use. At that point, I was able to start really going through and finding other applications that I wanted… I’d say, all things considered, I’ve probably spent around a week of the last 1.5 months compiling. Of course, a lot of that was just me getting used to the new system, playing, compiling, removing, etc. From a blank drive, the process would go a lot quicker now.

To be honest, when I first thought about having to wait for EVERYTHING to compile, I didn’t like it. I was accustomed to the speed of binary managers that just download a compressed file and run an installer. Now though, I think I’ve adopted a slightly different view. Once the base system is done, compiling packages here and there really doesn’t take much time since the dependencies are all already fulfilled. In short, I think the advantages are well worth the wait. If I’m about to install a program, I just have a synapse that fires telling me to go grab a cup of coffee while I wait. Not hard at all… a little more casual, in fact. While I certainly don’t look forward to the time investment of installing another Gentoo system, the stability and efficiency is such that I don’t think I would be happy any other way. And you know… there’s also a big difference in the size of the OS… compiling everything individually keeps you from installing useless software that you’ll never even look at. As of this writing, having nothing else on my list (at all!) in need of installation, and with a few things that could be removed, about 8 gigs are used. That includes data files and all. Compare that to a base install of a binary distro, or even (gasp!) Windows.

So there you go. If I’ve inspired you to try Gentoo, please let me know. If I can help you over some of the beginning hurdles, leave a comment and I’ll get in touch. If not, maybe after a few years of getting more familiar with your Linux distribution, you’ll decide it’s worth it. If nothing else, I hope this has been educational.

Happy Desktop-Linuxing!

install Pure-FTPd on Ubuntu

Tuesday, September 5th, 2006

I’m sure these instructions are similar for most distributions, but I thought I’d specifically target Ubuntu so that I don’t have to cover the little differences that each and every person might run into. The end result of this is to have a fast and secure FTP server running on Linux that, when given the proper credentials, will serve up a user’s home directory. You can imagine when this would be useful. I decided to go with Pure-FTPd for quite a few reasons, but mainly because of solid security and many configuration options. I’ve gotten myself into trouble before by choosing very simple FTPd servers and realizing later that they just weren’t able to do what I wanted them to do. Pure-FTPd is different that way.

So to get started, in Ubuntu just use apt to get Pure-FTPd installed:

apt-get install pure-ftpd

Now, set up a new user, and open up /etc/passwd for editing. Add /./ to their home directory like this:

/home/username/./

This keeps them from seeing the filesystem.

Also, make sure to put in a shell at the end of that line… /bin/bash works fine. After all of that, add their username to /etc/ftpallow.

Now it’s time to give Pure-FTPd a basic configuration. Edit /etc/pam.d/pure-ftpd to look like this:

auth sufficient pam_ftp.so
auth required pam_unix_auth.so shadow use_first_pass
auth required pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed
auth required pam_listfile.so item=user sense=allow file=/etc/ftpallow onerr=fail
auth required pam_shells.so

Now just type pure-ftpd-control restart on the command line and you’re all finished!