Thanks to Mozilla for providing excellent linux font DPI support.

On my Gentoo setup, I added a Xft.dpi setting go my ~/.Xdefaults file. Now my fonts look normal again. :)

Xft.dpi: 108

Before:

After:

Instructions for installing xorg-server and hal on gentoo.

I’m writing this because the gentoo documentation for X setup is very outdated. Gentoo now uses xorg 1.5 which uses hal to setup devices automatically instead of having to configure /etc/X11/xorg.conf. The Xorg 1.5 update guide might be a little helpful, but it’s missing some info and is a bit vague in places.

Xorg-server 1.5 setup

Make sure your kernel is compiled with Event interface support. (If not, see Gentoo Handbook: Configuring the kernel for help recompiling your kernel)

Device Drivers --->
 
Input device support --->
 
--- Input device support
[*]     Event interface

Add X and hal USE flags (the “–alpha-order” is optional, but I like to keep my USE flags organized)

flagedit --alpha-order +hal +X

(or equivalently with euse. euse is from the app-portage/gentoolkit package)

euse -E hal X

Add to /etc/make.conf

INPUT_DEVICES="evdev"
# Change the video driver to match your video card
# or install a bunch and let hal choose
VIDEO_DRIVER="nv nvidia radeon radeonhd intel sis via vesa fbdev"

Install xorg-server (which will also install hal since the hal USE flag is now enabled)

emerge -av xorg-server

Add hal policy files so hal can auto-detect your devices. Doesn’t hurt to add them all, hal will figure out what it needs.

cp /usr/share/hal/fdi/policy/10osvendor/* /etc/hal/fdi/policy

Add hald to startup and start hald

rc-config add hald default
/etc/init.d/hald start

Don’t need any /etc/X11/xorg.conf file

mv /etc/X11/xorg.conf /etc/X11/xorg.conf.bak

Now startx

startx

I recently configured the wireless on my X61 Tablet for Gentoo. I have a Intel 4965 AGN wireless card.

lspci | grep -i wireless
03:00.0 Network Controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)

Relevant kernel options (from gentoo-sources 2.6.28-r5 kernel)

Device Drivers  --->
  [*] Network device support  --->
    Wireless LAN  --->
      {*} Intel Wireless Wifi Core
      <M> Intel Wireless WiFi Next Gen AGN
        [*]   Intel Wireless WiFi 4965AGN

Install wpa_supplicant and wireless-tools

emerge -av wpa_supplicant wireless-tools

Create symlink so Gentoo will initialize the wlan0 at startup

cd /etc/init.d
ln -s net.lo net.wlan0

/etc/conf.d/net

modules=( "wpa_supplicant" )
iwconfig_wlan0="mode managed"
wpa_supplicant_wlan0="-Dwext"

/etc/wpa_supplicant/wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel
 
network={
  ssid="MySSID"
  scan_ssid=1
  key_mgmt=WPA-PSK
  psk="password"
  priority=5
}

I was getting SCICSIFFLAG File Not Found errors when trying to bring up my wlan0 interface. A look at the dmesg log revealed that the iwlagn module was trying to access iwlwifi-4965-2.ucode, so I emerged iwl4965-ucode to fix that.

emerge -av iwl4965-ucode

Reinitialize the interface to see if everything worked

/etc/init.d/net.wlan0 restart

Creating a bootable usb stick with the Gparted live iso in Ubuntu. Gparted is a graphical partition editor which can resize, move, copy, create, delete your hard drive partitions.

Overview:

• Format your usb stick to Fat16 and make it bootable using gparted.
• Install the gparted-live*.iso using unetbootin. (unetbootin also automatically installs the syslinux bootloader)
• Reinstall syslinux onto usb stick. (Gparted’s live cd requires syslinux newer than ver 3.71. Currently (May 7 2009) Ubuntu 9.04 Jaunty has syslinux 3.63. Use apt-cache show syslinux | grep "^Filename" to check Ubuntu’s version)

Installation Steps

1. Install gparted and unetbootin

sudo aptitude install gparted unetbootin

2. Download the gparted live iso and the latest syslinux.

wget http://superb-west.dl.sourceforge.net/sourceforge/gparted/gparted-live-0.4.4-1.iso
wget http://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-3.80.tar.bz2

3. Insert your usb stick into the computer, and copy any files you want to save to your hard drive. You will be reformatting your stick and will lose all the files on the usb drive.

4. Run gparted.

sudo gparted

Select your usb drive. (Probably something like /dev/sdc). Right click on the partition and select Unmount to unmount the drive. Format the drive to Fat16 and apply. Then make the usb drive bootable by going to Manage Flags and selecting the boot flag.

Exit gparted.

5. Remount your usb drive by unplugging and replugging your usb stick.

6. Run unetbootin

unetbootin

Select Diskimage ISO and locate the gparted-*.iso that you downloaded. Make sure the correct partition is selected at the bottom and click OK.

Don’t reboot yet. Just exit unetbootin.

7. Now, you would be done, except that Ubuntu’s syslinux is version 3.63 and the gparted live iso requires at least syslinux version 3.71, so you need to reinstall syslinux onto your usb stick.

Unpack the syslinux tarball you downloaded.

tar xjvf syslinux-3.80.tar.bz2

Now install syslinux onto your usb stick

cd syslinux-3.80/linux
sudo ./syslinux -s /dev/sdc1

8. Now you’re done. Reboot using your new gparted bootable usb stick.

End Notes:

This method should work on other bootable isos too.

You could try to use Fat32 if your motherboard supports booting from Fat32 USB devices. Fat16 is generally more compatible though.

If your USB stick is bigger than the the allowable Fat16 size (2gb), make two partitions: first a 1-2gb Fat16 partition for your boot drive, and a second Fat32 partition with the rest of the space.

Add these lines to your ~/.bashrc to make colorful grep | less output.

alias grep='grep --color=always'
export LESS='-R'

Often the unix commands basename and dirname are useful in shell scripts, but how do you use these in c or c++?.

The C way: libgen.h

If you’re working in c, the posix header libgen.h provides dirname and basename functions, with some limitations: They only work with char *, and dirname will modify the char * you pass into it so you need to make a copy of your original path if you wish to keep it. Example code:

// libgen_example.c
// Demonstrate libgen.h usage and pitfalls
// Compile:  gcc -g -o libgen_example libgen_example.c
#include
<libgen.h> //basename and dirname
#include <string.h> //strlen and strcpy
#include <stdio.h> //printf
#include <stdlib.h> //malloc
 
int main(int argc, char* argv[]) {
    // Demonstrate how dirname changes the path you input to it
    char path[] = "default/path/to/nowhere.txt";
    printf("path='%s'\n", path);
    char * dir = dirname(path);
    printf("path='%s'  dir='%s'\n", path, dir);
    char * base = basename(path);
    printf("path='%s'  dir='%s'  base='%s'\n\n",
           path, dir, base);
    // Since dirname changed path, base is now "to"
    // instead of "nowhere.txt" as we might have expected.
    // Output:
    // path='default/path/to/nowhere.txt'
    // path='default/path/to'  dir='default/path/to'
    // path='default/path/to'  dir='default/path/to'  base='to'
 
    //========
    // Demonstrate c string copying
    const char * another_path = "another/path";
    char * modifiable_copy = (char *)malloc(strlen(another_path) + 1);
    strcpy(modifiable_copy, another_path);
    char * another_dir = dirname(modifiable_copy);
    printf("another_path='%s'\n", another_path);
    printf("modifiable_copy='%s'\n", modifiable_copy);
    printf("another_dir='%s'\n\n", another_dir);
    // note that after this free, another_dir is now also
    // invalid since it pointed to the modifiable_copy's memory
    free(modifiable_copy);
    // Output:
    // another_path='another/path'
    // modifiable_copy='another'
    // another_dir='another'
 
    //========
    // const strings declared as char * can cause segfaults
    char * char_pointer_path = "char/pointer/path";
    printf("char_pointer_path='%s'\n", char_pointer_path);
 
    char * char_pointer_dir = dirname(char_pointer_path);
    printf("char_pointer_path='%s' char_pointer_dir='%s'\n",
           char_pointer_path, char_pointer_dir);
    // Output:
    // char_pointer_path='char/pointer/path'
    // Segmentation fault
}

The C++ way: boost::filesystem

If you’re looking for a better c++ solution, see the c++ boost filesystem library. boost::filesystem::path.parent_path() can be used like dirname and boost::filesystem::path.filename() acts like basename.

The boost::filesystem library also has many other useful functions for dealing with files and paths (e.g. fs::complete(path) for obtaining an absolute path, fs::exists(path) will check if the path exists, fs::create_directories(path), fs::remove(path), fs::copy_file(from,to) name a few). Note that some of these are functions are boost::filesystem::path methods and some are in boost::filesystem. According to the faq, operations done by the operating system are provided in boost::filesystem functions, but functions just performed on the lexical path (just path string manipulations) are provided as boost::filesystem::path methods.

// filesystem_example.cpp
// Demonstrate using boost::filesystem
// Compile:  g++ -I /usr/local/include/boost-1_38/ -L /usr/local/lib -lboost_filesystem-gcc41-mt-1_38 -o filesystem_example filesystem_example.cpp
#include <boost/filesystem.hpp>
#include <iostream>
namespace fs = boost::filesystem;
 
int main(int argc, char* argv[])
{
    fs::path pathname("default/path/to/nowhere.txt");
    std::string dirname  = pathname.parent_path().string();
    std::string basename = pathname.filename();
 
    std::cout << "pathname = " << pathname << std::endl;
    std::cout << "dirname = " << dirname << std::endl;
    std::cout << "basename = " << basename << std::endl;
    // Output:
    // pathname = default/path/to/nowhere.txt
    // dirname = default/path/to
    // basename = nowhere.txt
 
    std::cout << std::endl;
    std::cout << "extension = " << pathname.extension() << std::endl;
    std::cout << "complete = " << fs::complete(pathname) << std::endl;
    std::cout << "exists = " << ((fs::exists(pathname)) ? "true" : "false") << std::endl;
    // Output:
    // extension = .txt
    // complete = /home/moose/default/path/to/nowhere.txt
    // exists = false
}

My experiences as a [g]vim user trying out emacs.

Day 1:

Emacs commands

Running emacs was no problem, as it was already installed from Fedora’s repository. Reading through some emacs tutorials, I found Emacs For VI Users very helpful.  Probably my most used  vi commands are delete line (dd), yank line (yy), and put (p or P).  Emacs  confusingly uses “yank”  to describe the  vi equivalent “put” command of inserting saved text into the document.  Getting used to the sequences of ctrl / alt + key is strange when I’m used to the efficient vi commands.  ”yy” becomes “Ctrl+a  Ctrl+k Ctrl+k Ctrl+/”.

Tab behavior

Started trying to edit some c++ files using emacs, but found that the default tabbing behavior was messing up my indentation.  The default emacs uses 2 spaces per indentation, and will use the tab key to automatically indent code instead of inserting a tab character.  I like to tab-indent my code and view it as 4 spaces / tab.  This was frustratingly difficult to solve, as emacs has so many options, and many of the emacs options have cryptic names and unclear descriptions.  I finally found some sane lines to put into my ~/.emacs file from Emacs Tips N Tricks For Everybody.  The

(global-set-key "\C-m" 'newline-and-indent)

line is really nice to emulate vi’s autoindent feature. Understanding GNU Emacs and Tabs is also useful for understanding emacs’s special tabbing behavior.

Day 2:

Antialiased fonts

Discovered that emacs 23 supports antialiased fonts, but there’s no stable release yet, and no Fedora 8 rpm.  So, I downloaded the source from cvs and built.  Now running

emacs --font="monospace-10"

works, and emacs looks great.

Start in background

I wrote a bash wrapper to always start emacs in the background (similar to gvim) with the monospace font.

#!/bin/bash
# start emacs in the background with the monospace font
exec emacs-23.0.92.1 --font="monospace-10" "$@" &

My ~/.bashrc has an alias to run this wrapper. (I put the wrapper in ~/bin/emacs)

# .bashrc alias
alias emacs="~/bin/emacs"

Matlab files

Opening a matlab .m file tries to use the ObjC mode. You can add the matlab mode to emacs using the matlab.el file from matlab-emacs. I put the file at ~/.emacs_addons/matlab.el and added these lines to my ~/.emacs file:

; Add addons dir to path
(setq load-path
      (append (list nil "~/.emacs_addons")
              load-path))
; Add matlab.el module
(autoload 'matlab-mode "matlab" "Enter MATLAB mode." t)
(setq auto-mode-alist (cons '("\\.m\\'" . matlab-mode) auto-mode-alist))
(autoload 'matlab-shell "matlab" "Interactive MATLAB mode." t)

Regular expressions

Emacs offers search and replace with regular expressions using the Ctrl-Alt-% command, with some caveats

Tab bar

Opening multiple files in emacs puts each file into a buffer, but there is no [g]vim/firefox-like tab bar which shows the open files. You have to go through the list of buffers or split your window. But at least there is the TabBar mode addon.

Find the manufacturer and version of your motherboard with this command:

sudo dmidecode | grep "Base Board" -A 13

Example output:

Base Board Information
        Manufacturer: ASUSTeK Computer INC.
        Product Name: Maximus Formula
        Version: Rev 1.xx
        Serial Number: XXXXXXXXXXX
        Asset Tag: To Be Filled By O.E.M.
        Features:
                Board is a hosting board
                Board is replaceable
        Location In Chassis: To Be Filled By O.E.M.
        Chassis Handle: 0x0003
        Type: Motherboard
        Contained Object Handles: 0

A few sites to keep updated on election day:

Google Election Maps Shows live and historic results, polls, and Palin and Biden’s life journey

Google Election 2008 News Information on voting and election news

AP Election 2008 News Election news and webcasts

CNN Election Results

So even though hash_map and hash_set aren’t a part of the C++ standard, there are still implementations included with the gcc compiler. You have to include or and a little magic to get them to work properly with std::string keys.

// Example code using a hash_set with std::string keys on gcc
// Example based on hash_set code from "6.7 Using Hashed Containers"
// in O'Reilly C++ Cookbook by Stephens, Diggins, Turkanis & Cogswell  (2006)
// and gcc fix from post http://gcc.gnu.org/ml/libstdc++/2002-04/msg00107.html
// Tested with g++ 4.1.2
// Compile with:
// g++ -o hash hash.cpp
// Kristi Tsukida <kristi.tsukida at gmail dot com> 30-10-2008
 
#include <iostream>
#include <string>
#include <ext/hash_set>
 
using namespace std;
// The __gnu_cxx namespace contains the hash_set since it's not standard c++
using namespace __gnu_cxx;
 
// This is the magic that will allow the usage of string keys in the hash
namespace __gnu_cxx
{
        template<> struct hash< std::string >
        {
                size_t operator()( const std::string& x ) const
                {
                        return hash< const char* >()( x.c_str() );
                }
        };
}
 
// must specify the hash<string> hash function
typedef hash_set<string, hash<string> > string_hash_set;
 
int main()
{
	string_hash_set hs;
 
	string s = "bravo";
	hs.insert(s);
	s = "alpha";
	hs.insert(s);
	s = "charlie";
	hs.insert(s);
 
	for(string_hash_set::const_iterator p = hs.begin(); p!= hs.end(); ++p)
	{
		cout << *p << endl;
	}
 
}

General instructions to rebuild a Fedora source rpm.

Note: This example uses the vlc source rpm, but it doesn’t work on my Fedora 8 system because there are problems installing dependencies, but the general commands should work on other packages

1. Install build tools

   su -c 'yum install yum-utils rpmdevtools'

2. Download source package. Either use yumdownloader to download from an existing repository:

   yumdownloader --source vlc

   or download directly from a server

   wget -nd ftp://ftp.pbone.net/mirror/rpm.livna.org/fedora/development/SRPMS/\
   vlc-0.9.0-0.5.20080802git.lvn10.src.rpm

3. Install the source package. This will unpack the source into your /$HOME/rpmbuild directory.

   rpm -Uvh vlc-0.8.6i-1.lvn8.src.rpm

4. Install build dependencies for the source package

   su -c 'yum-builddep vlc-0.8.6i-1.lvn8.src.rpm'

5. Edit the spec file

   cd ~/rpmbuild/SPECS
   vim vlc.spec

6. Add the new source package

   cd ../SOURCES
   wget -nd http://download.videolan.org/pub/videolan/vlc/0.9.2/vlc-0.9.2.tar.bz2

7. Build the rpm

   cd ../SPECS
   rpmbuild -bb vlc.spec

8. Install the rpm

   cd ../RPMS/x86_64
   rpm -Uvh vlc-0.9.2.fc8.x86_64.rpm

References:
Building a kernel from the src rpm
Fedora rpm guide

Skymaps provides free monthly constellation maps which are nicely printable. It also includes a monthly list of astronomical events such as meteor showers, eclipses, and moon phases.

Add all files which aren’t currently under version control to the svn:ignore property.

for line in $(svn status | grep ^? | awk '{print $2}')
do
    pushd $(dirname $line)
    svn propset svn:ignore "$(svn propget svn:ignore)$(echo -e "\n$(basename $line)")" .  
    popd
done
svn commit

isnoop tracker screenshot

Isnoop pachage tracker will generate an rss feed for UPS, FedEx, USPS, or DHL package tracking information and view your package’s path in a google map. Useful when you’re anxiously awaiting a package to arrive.

So it’s possible to run the Google Chrome browser using Wine (latest dev version 1.1.4), though it’s kinda slow, and won’t do any https sites.

Ubuntu thread w/ instructions (These didn’t work for me on Fedora 8)

Wine App DB page w/instructions (These worked for me on Fedora 8)