A Story Worth Telling

Making and applying patches

Joseph — Tue, 24 Jan 2012 18:53:24 +0000

This is actually something quite simple, so simple in fact that there is not much documentation for it. Anyways, to make the patch:

diff -urN file.orig file.modified > file.patch

then to turn a copy of file.orig into file.modified

patch file.orig file.patch

And then file.orig is updated to match file.modified.

Grep for a tab Character

Joseph — Wed, 26 Oct 2011 15:41:04 +0000

Need to grep for a tab in a file, but don’t know how to do it. Here’s one plan, say I wanted to grep for the number 1 followed by a tab…

grep -E "1`echo -e '\t'`" file.txt

So I’m actually using echo to print the tab special character into my grep string before the shell passes it on to grep. If this makes sense to you it’s time to start worrying…

Alphabetize XFCE desktop icons

Joseph — Wed, 19 Oct 2011 04:53:42 +0000

A little script that alphabetizes desktop icons in xfce, folders before files, and hides files with a ~ at the end or a . at the beginning (hides hidden files). You can grab it here.

VLC d-bus documentation

Joseph — Wed, 19 Oct 2011 04:50:14 +0000

Because I had to search far and wide, here are some vlc dbus methods, I can’t quite get all of them to work.

/ – identify the player
/TrackList – get the tracklist
GetMetadata : Gives all meta data available for element at given position in the “TrackList”
GetCurrentTrack : Position of Current URI in the “TrackList”
GetLength : Number of elements in the “TrackList”
AddTrack : Appends an URI in the “TrackList”, play it immediately if the 2nd argument is TRUE
DelTrack : Removes an URI from the “TrackList”, given its position
/Player – ?
Next : Goes to the next element (what if we’re at the end?)
Prev : Goes to the previous element (what if we’re at the beginning?)
Pause : If playing : pause. If paused : unpause. If stopped : start playing
Stop : Stop playing.
Play : If playing : rewind to the beginning of current track, else : start playing.
Quit : Makes the “Media Player” exit.
GetStatus : Return the status of “Media Player”: 0 = Playing, 1 = Paused, 2 = Stopped.
VolumeSet : Sets the volume (argument must be in [0;100])
GetVolume : Returns the current volume (must be in [0;100])
PositionSet : Sets the playing position (argument must be in [0;100])
PositionGet : Returns the playing position (must be in [0;100])

apt-fast with preview, autocompletion and installer script

Joseph — Tue, 18 Oct 2011 21:28:14 +0000

There were a few things that were preventing me from adopting use of Matt Parnell’s apt-fast wrapper for apt-get.
1) no preview of action – i.e. when I install a package, it downloads all the files before it tells me what it would be doing, if it’s going to install packages I don’t want I don’t want to waste the time downloading the packages.
2) no autocompletion – was the library libexifjpeg62-0-dev or libexifjpeg62.0-dev, now you don’t have to know
3) there was no easy method of installing (not that that was much of an impediment), it was really the first two.

Anyways, I’ve made some modifications and now it supports all 3, that is preview of action before download, autocompletion of both action names and package names, and an installer script. Everything tested on some variant of *buntu. You can find the mods here.

Video thumbnails in Thunar

Joseph — Sat, 15 Oct 2011 22:18:36 +0000

The thunar-thumbnailer packages have been retired and replaced by tumbler, but tumbler is quite unhelpful unless you also grab the tumbler-plugins-extra package. Now I happily have thumbnails for almost every file type on my machine that makes sense to thumbnail.

One Wallpaper/Background per desktop/workspace in Ubuntu with Icons

Joseph — Wed, 12 Oct 2011 15:30:14 +0000

It seems the current best solution with respect to multiple wallpapers involves giving up desktop icons. I’ve written a rather hackish alternative, which instead gives up instantaneous transitions between one wallpaper and the next (they now take about half a second). The code is reproduced below, but I recommend grabbing the original here (which preserves pretty indentation).

#!/usr/bin/perl # desktop_watcher.pl # written Joseph Bylund, 2011/10/12 # this script watches for desktop changes, and when it finds one it changes the background. Currently this is a hackjob, but it # should work if you fix the paths and number the files you'd like to use as 1.jpg, 2.jpg, 3.jpg (for workspaces 1,2,3 # respectively). You can even use xml files as per the cosmos background as your backgrounds, just rename to 1.xml, # 2.xml ... You'll also have to change the extension to xml from jpg. # also update the path_to_bg_files to where you're keeping your background files.


use strict;
use Time::HiRes qw( nanosleep );
my $extension = "jpg";
my $user = `whoami`;

chomp($user);
my $path_to_bg_files = "/home/$user/Desktop/multi_wallpaper_test";
my $workspace_width = `wmctrl -d|head -n 1`;

chomp($workspace_width);

$workspace_width =~ s/.*WA: [^ ]* //;

$workspace_width =~ s/x.*//;

$workspace_width = int($workspace_width);

print "width = $workspace_width\n";
my $window_manager = &get_window_manager;

print "using $window_manager\n";

my $last_workspace = &get_workspace($window_manager,$workspace_width);

my $current_workspace = $last_workspace;
my $counter = 0;
while(1)

{

$current_workspace = &get_workspace($window_manager,$workspace_width);

if($current_workspace != $last_workspace)

{

$last_workspace = $current_workspace;

system("gconftool --type string --set /desktop/gnome/background/picture_filename \"$path_to_bg_files/$current_workspace.${extension}\"");

}

nanosleep(int(0.5*10^9)); # increase sleep timer to reduce cpu usage, decrease to improve response time

}
sub get_workspace

{

my $window_manager = shift;

my $workspace_width = shift;

my $current_workspace;

if($window_manager eq "metacity")

{

$current_workspace = `wmctrl -d|grep \\*`;

chomp($current_workspace);

$current_workspace =~ s/.*Workspace//g;

$current_workspace =~ s/\s*//g;

$current_workspace;

}

else

{

my $current_vp = `wmctrl -d`;

chomp($current_vp);

$current_vp =~ s/.*VP: //;#cut off leading

$current_vp =~ s/,.*//;#cut off trailing

$current_workspace = $current_vp/$workspace_width + 1;

}

}

sub get_window_manager { my $lines = `wmctrl -d|wc -l`; chomp($lines); if($lines > 1) {"metacity";} else {"compiz";} }

Making Coreutils without SELinux

Joseph — Wed, 05 Oct 2011 19:51:38 +0000

Because selinux is annoying, and not installed on all machines, and sometimes you want to use the same binaries on multiple machines sharing one fileserver for home directories, but not for library files required by selinux.
./configure --without-selinux --disable-acl
Simple as that.

Printing to a hp 3600dn in ubuntu 11.04

Joseph — Tue, 04 Oct 2011 19:06:52 +0000

I’ve always had a terrible time of printing to an hp3600 dn, either I would get pcl errors or weird colors, occasionally I’d even get the right number of pages printed but they’d all be blank. After a bit of hunting it seems I have found a solution. It’s a solution in multiple parts as there are multiple bugs. First, a few packages I recommend installing if you don’t have them already (formatted for command line so you can copy and paste):
sudo aptitude install libcups2-dev libcupsimage2-dev libdbus-1-dev libsane-dev libsnmp-dev libusb-dev python-dev python-qt4-dbus python-reportlab xsane

Then get the source to the libjpeg62 package, I according to this bug report there is an error in the makefile, so I was expecting to have to remove that flag, but I didn’t see the flag at all, so I just didn’t worry about it:
apt-get source libjpeg62

Change to the directory you just got:
cd libjpeg6b-6b1/

Make the makefile with all the proper options, you may have to install additional packages here:
./configure

Actually make and install:
make sudo make install

You also should make sure that your user is in both the lp group and the lpadmin group.

Then I’d recommend deleting any printer you may have. Then start adding a printer, type in the ip address, the passthrough port is fine. Select hp for the brand, and hp3600* for the model (i.e. “color laserjet 3600dn” or whatever’s appropriate for your model). Finally in the program you’re actually printing from (in my case evince), make sure you haven’t altered the print quality setting (it will give a pcl error if you do, it should be set to normal). Double sided printing works, variable quality printing doesn’t, I also believe grayscale is on the no-go list. Anyways, hope that helps.

Opening a Large Number of PDB’s a few at a Time

Joseph — Tue, 28 Jun 2011 18:27:41 +0000

I sometimes find it convenient to open a large number of pdb files for visualization a few at a time (to check alignment, bond orders…). And I had originally had a bit of trouble coming up with an easy way to do this. I imagine this is somewhat ubuntu/gnome specific, but I thought it might be helpful to some folk:

ls *.pdb|xargs -n 10 gnome-terminal –disable-factory -x /opt/bin/vmd -nt -m