I document my adventures and problems so that I remember my mistakes, and perhaps you may learn something.
I'm not a programmer, nor a computer expert.
I'm just a tinkering guy in Milwaukee with a store and three kids to keep me busy.
Ripping a CD to add to my music collection using the command-line application abcde.
To install abcde, use sudo apt-get abcde
To rip a CD, insert the CD and use the terminal. This will rip the CD to FLAC (lossless) format, and eject the CD when complete:
cd Music abcde -x -o flac
To install epub-utils and fbreader, use sudo apt-get epub-utils fbreader
To convert a book file, use lit2epub /path/to/book.lit
To read a converted book, open fbreader and point it to /path/to/book.epub
I have a snazzy new geek-phone, a Shuttle from Virgin Mobile. It has a 4GB MicroSD slot so files can be exchanged with my Xubuntu system.
$ mencoder media/disk/my_flix/inputfile.3g2 -ovc lavc -lavcopts vcodec=msmpeg4v2 -oac mp3lame -lameopts vbr=3 -o Videos/outputfile.avi
$ convert Pictures/filename -size 320x240 /media/disk/my_pix/filename.jpg
Important information- UUID=5D18-F276 # The 4GB MicroSD Card's UUID. Find using syslog after plugging it in /media/disk # Default mount point /dev/sdb1 # Device location /dev/sdb1 /media/disk vfat rw,nosuid,nodev,uhelper=hal,utf8,shortname=winnt,uid=1000 0 0 # /etc/mtab entry for the disk /media/disk/my_flix /media/disk/my_music /media/disk/my_pix # Available folders Camera Resolutions: 1280x960 1024x768 640x480 320x240 176x144 160x120 Video Camera Resolution: 176x144 Screen Resolution: 220x176, 262k colors
What went well: I created a set of Restore DVDs (in case I want Windows back), then removed windows and installed Xubuntu 9.04 full-disk. Copied over my old /home directory, and installed all my favorite apps. E-mail, web, games, .bashrc, most dektop settings, etc. transferred without a hiccup. Recreated my crontab. Wireless networking and video work great. Built-in card reader reads all cards from my cameras and phone. Machine is noticeably faster. FN-key brightness control works. FN-key multimedia controls work.
Solved Problems:
/etc/modprobe.d/alsa-base.conf
somwhat improved speakers and fixed the headphone jack.# Added by me on <date> while troubleshooting audio options snd-hda-intel model=6stack
Unsolved Problems: No built-in webcam. Keyboard is different, and will take time to get used to - many typos in the meantime.
My spouse wants to create art using carefully-arranged Rubik's Cubes. She needs a tool to do it: She needs to manipluate images to the right color and pixellation to look cube-ready (Solving them to the displayed configuration is another issue).
So let's set up The GIMP to do it.
Preparation: GIMP needs to know what colors to use, so let's create a custom color pallette. (This only needs to be done the first time)
File -> Create -> From ClipboardImage -> Mode -> Indexed -> Use Custom Palette -> Open The Palette Selection Dialog -> New PaletteChanging an image
Image -> Mode -> Indexed -> Use Custom Palette -> Cube ColorsImage -> Scale Image Pick a small size that is a multiple of 3 (3 rows/colums on each cube)Scripting for batch-resizing: This looks possible using Imagemagick - see "using pre-defined color maps" for an easy way to get Imagemagick to reduce the colors.
Our store has a 7-inch photo frame, with a 2GB stick in it. So we can just drag-and-drop lots of photos onto the stick.
But how can we use Imagemagick, the command-line photo editor, to batch-resize a whole bunch of images...perhaps as part of a script?
$ mogrify -sample 480 foldername/filename.jpg
$ mogrify -sample 400 foldername/*.jpg
$ mkdir copies $ cp original/image.jpg copies/ $ mogrify -sample 400 copies/image.jpg $ mv copies/image.jpg stick/
Instead of the installation disks, I used these instructions
Then go into Settings -> Printer -> Add New Printer and let it autodetect the new printer on the network.
Here is how to get a custom script to run at XFCE startup:
custom_startup.sh. You can put anything in the script; in there now is only a logger so you know it's working.#!/bin/sh # This script is run automatically by xfce4-desktop during system startup. logger -i "Running the custom startup script"
/home/me/.config/autostart/MyStartup.[Desktop Entry] Encoding=UTF-8 Version=0.9.4 Type=Application Name=MyStartup Comment= Exec=bash /home/me/Scripts/startup_script.sh StartupNotify=false Terminal=true Hidden=false
#!/bin/sh
# BEGIN CONFIGURATION
# This is the path of the final output files that get read by other processes.
# Working files show up here, too. You may wish to create your own directory.
Local_Path=/home/me/.config/weather/
Local_Name="${Local_Path}radar_image.png"
Username=<your username>
# This is the closest weather station for observations. Find your weather
# station: http://www.nws.noaa.gov/xml/current_obs/. Format is four letters.
# All UPPER CASE. For example, 'KMKE' for Mitchell Field in Milwaukee, WI
Station=KMKE
# This is the closest weather radar. Find your radar: http://radar.weather.gov/
# Check the link to your weather radar, for example:
# http://radar.weather.gov/ridge/radar.php?rid=mkx&product=N0R&overlay=11101111&loop=no
# The radar name is in the 'rid=' field. In this example, mkx is Milwaukee, WI
# Format is UPPER CASE. For example, 'MKX' for Milwaukee.
Radar_Name=MKX
Radar_Url="http://radar.weather.gov/lite/N0R/${Radar_Name}_0.png"
# (OPTIONAL) The height of your top menu bar, in pixels.
# The radar image is padded by this amount on the top edge so the menu doesn't
# block the timestamp in the image.
#Radar_Image_Top_Padding=15
# END CONFIGURATION
# BEGIN RADAR IMAGE
# Download the radar image.
echo "Weather Update: Downloading the most recent radar image available..."
curl -o $Local_Name $Radar_Url
# (OPTIONAL) Use imagemagick to pad the image top so the timestamp is not
# blocked by the menu bar.
#convert $Local_Name -background none -splice 0x${Radar_Image_Top_Padding} $Local_Name
# Refresh desktop background with 'xfdesktop -reload'. NOTE - some versions
# of XFCE flicker all the icons brighter when this occurs, providing visual
# feedback that the refresh occurred. An Alternate method to avoid the
# flicker is below.
# The 'DISPLAY=:0.0' prefix is required so root processes like cron and
# Upstart can process it.
# The 'sudo -u $Username' is required because a root process (like an Upstart
# trigger) may be trying to change a user's desktop. Sudo changes the command
# to run as user instead of root. Use your username, of course.
DISPLAY=:0.0 sudo -u $Username xfconf-query -v -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s $Local_Name
DISPLAY=:0.0 sudo -u $Username xfdesktop -reload
# Alternate method to avoid the flicker by changing desktop pictures for
# just a moment, then changing it back.
#DISPLAY=:0.0 sudo -u $Username xfconf-query -v -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s /usr/share/xfce4/backdrops/xfce4logo.png
#DISPLAY=:0.0 sudo -u $Username xfconf-query -v -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s $Local_Name
# END RADAR IMAGE
I'll save this script as radar_background.sh, and make it executable with sudo chmod +x radar_background.sh.DISPLAY=:0.0 element is explained here.xfconf-query command, and how to change the background using DBus, are discussed in the XFCE forumsnano .bashrc opens the .bashrc for editing.alias radar='/home/me/radar_background.sh' to the bottom of the file and save it.radar.# m h dom mon dow command */20 * * * * /home/me/radar_background.shNote that the desktop picture will refresh every 20 minutes.
# m h dom mon dow command - That's just part of the crontab*/20 * * * * - tells the machine to run the script every 20 minutes. */5 * * * * will run the script every five minutes. > /dev/null at the end (optional) - tells the machine to not e-mail me every time the script runs.After the previous reinstall two months ago, DVDs stopped working.
Here's how I got it to work:
sudo cp /etc/apt/sources.list /etc/apt/sources.list~ # Backup the sources.list file sudo mousepad /etc/apt/sources.list & # Open the sources.list file in an editing window ## In sources.list, append the following two lines at the bottom, then save (don't close it) ## Medibuntu deb http://packages.medibuntu.org/ jaunty free non-free ## If you use debtorrent, use: deb debtorrent://localhost:9988/packages.medibuntu.org/ jaunty free non-free sudo apt-get update sudo sudo apt-get install medibuntu-keyring sudo apt-get update
sudo apt-get install totem-xine libxine1-ffmpeg libdvdread4 sudo /usr/share/doc/libdvdread4/install-css.sh # Note - this installs the libdvdcss2 package, which is *not* in the repositories. # If you use this list of packages to rebuild your system, for example by using a # Jablicator metapackage, it will fail due to this missing dependency.
sudo apt-get install ubuntu-restricted-extras
"Could not open location; you might not have permission to open the file." This is indeed a permission issue. Fix it with:sudo chmod 755 /media/cdrom0And then try opening the DVD from within your player application (Totem).
About a month ago, audio suddenly stopped working. Rather than troubleshoot, I decided to reinstall...it might be faster. Unlike last time, this time was a complete reinstall to get rid of certain dependency problems that had also cropped up.
A convenient way to create a metapackage is the jablicator command-line application, included in the package of the same name.
Jablicator creates a metapackage with all current packages as the dependencies. So you can edit the dependencies to limit metapackage, or take a snapshot of your packages for easy restoring after an update.
In mail-notification 5.4 in Ubuntu Jaunty (9.04), the following files are installed to /usr/lib/evolution/2.24/plugins/ instead of /usr/lib/evolution/2.26/plugins/:liborg-jylefort-mail-notification.soorg-jylefort-mail-notification.eplug
sudo ln -s /usr/lib/evolution/2.24/plugins/org-jylefort-mail-notification.eplug /usr/lib/evolution/2.26/plugins/ sudo ln -s /usr/lib/evolution/2.24/plugins/liborg-jylefort-mail-notification.so /usr/lib/evolution/2.26/plugins/
wodim dev=$PATH-TO-DEVICE driveropts=burnfree -v -data $PATH-TO-ISO, so in my case wodim dev=/dev/scd0 driveropts=burnfree -v -data /home/me/Ubuntu\ Images/xubuntu-9.04-desktop-i386.iso. Very easy and fast that way.sudo cp /etc/apt/sources.list /etc/apt/sources.list~ # Backup the sources.list file sudo mousepad /etc/apt/sources.list & # Open the sources.list file in an editing window ## In sources.list, append the following two lines at the bottom, then save (don't close it) ## Medibuntu deb debtorrent://localhost:9988/packages.medibuntu.org/ jaunty free non-free sudo apt-get update sudo sudo apt-get install medibuntu-keyring debtorrent apt-transport debtorrent ## In sources.list, substitute each occurrence of the string 'deb http://' prefix with 'deb debtorrent://localhost:9988/' ## Save and close the sources.list file. sudo apt-get update
| Subject | Packages I Removed | Packages I Added | Install Notes |
| thunderbird | evolution spamassassin mail-notification-evolution | Evolution needed a couple restarts to start working properly | |
| Scripting | bluefish d-feet curl devscripts | ||
| Fonts | msttcorefonts ttf-droid | ||
| Codecs | gstreamer0.10-ffmpeg gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad libdvdcss2 | Download-at-first-need for audio also works well. | |
| Printing | cups-pdf | ||
| GPS | gpsd python-gps | ||
| Remote desktop | vinagre | openssh-server xtightvncviewer | xtightvncviewer required manual config: sudo update-alternatives --set vncviewer /usr/bin/xtightvncviewer |
| Network | transmission-gtk xchat | deluge skype | |
| Office | openoffice.org openoffice.org-gtk | ||
| Other | bluez bluez-gnome bluez-cups gnome-pilot | wine simutrans powertop inkscape flashplugin-installer pmount | blues-gnome gets rid of bluetooth-applet pmount mounts usb drives as user instead of root |
| Non-Ubuntu | skype4pidgin | http://eion.robbmob.com/skype4pidgin.deb |
sudo cp -l imadison.py /bin/imadisonrmadison is part of the devscripts package. It's a fantastic little tool that tells you which version of a package is in which release of Ubuntu or Debian. It's also the quickest way to see if a package is in one of them at all - very handy to check package requests on Launchpad and in Brainstorm.
apt-cache is part of the default Ubuntu install. It's very handy to find the right package name, dependencies, and other clues when tracking down the correct package for Launchpad or Brainstorm.
sudo apt-get install debtorrent apt-transport-debtorrent ), or synaptic./etc/apt/sources.list to take advantage of debtorrentdeb http://ftp.us.debian.org/debian etch main contrib non-free #OLD deb debtorrent://localhost:9988/ftp.us.debian.org/debian etch main contrib non-free #NEW # Do not modify deb-src lines
sudo apt-get updateTwo methods to scan for wireless networks. One requires sudo/root, the other requires Network Manager.
#! /usr/bin/env python
"""This python 2.5 script uses iwlist to scan for nearby wireless networks. It must be run as sudo/root to work."""
import subprocess as SU
command = ['iwlist', 'eth1', 'scan']
output = SU.Popen(command, stdout=SU.PIPE).stdout.readlines()
data = []
for item in output:
print item.strip()
if item.strip().startswith('ESSID:'):
data.append(item.lstrip(' ESSID:"').rstrip('"\n'))
if item.strip().startswith('Quality'):
data.append(int(item.split()[0].lstrip(' Quality=').rstrip('/100 ')))
if item.strip().startswith('Encryption key:off'): data.append('OPEN')
if item.strip().startswith('Encryption key:on'): data.append('encrypted')
print data
#! /usr/bin/env python
"""This python 2.5 script uses dbus to query Network Manager, which scans regularly for wireless networks. It does NOT require root/sudo."""
import dbus
item = 'org.freedesktop.NetworkManager'
path = '/org/freedesktop/NetworkManager/Devices/eth1'
interface = item + '.Device'
bus = dbus.SystemBus()
data = []
wireless = dbus.Interface(bus.get_object(item, path), interface)
for network_path in wireless.getNetworks():
network = dbus.Interface(bus.get_object(item, network_path), interface)
data.append(network.getName()) # also network.getProperties[1]
data.append(network.getStrength()) # also network.getProperties[3]
if network.getEncrypted(): data.append('encrypted')
else: data.append('OPEN')
print data
os.popen() with subprocess.Popen() in Python
In Python, you can execute shell commands using the os.popen method...but it's been deprecated in favor of a whole new command.
# The old way, which worked great!
import os
shell_command = 'date'
event = os.popen(shell_command)
stdout = event.readlines()
print stdout
# The new way, which is more powerful, but also more cumbersome.
from subprocess import Popen, PIPE, STDOUT
shell_command = 'date'
event = Popen(shell_command, shell=True, stdin=PIPE, stdout=PIPE,
stderr=STDOUT, close_fds=True)
output = event.stdout.read()
print output
# The new way, all in one line (a bit uglier), works in Python3!
import subprocess
output = subprocess.Popen('date', stdout=subprocess.PIPE).stdout.read()
print output
$ps -e | grep `cat /var/run/dbus/pid` # Confirm if DBus is running by checking for the PID number in the list of live processes.
# If DBus is running, this will return the process number.
# If not, it will return nothing.
$sudo rm /var/run/dbus/pid # Remove the stale pid file so DBus can be restarted.
$sudo dbus-daemon # Start DBus again.
#! /usr/bin/env python
import dbus
bus = dbus.SystemBus()
item = 'org.freedesktop.NetworkManager'
eth0_path = '/org/freedesktop/NetworkManager/Devices/eth0'
eth1_path = '/org/freedesktop/NetworkManager/Devices/eth1'
interface = 'org.freedesktop.NetworkManager.Devices'
# There are two possible network interfaces: eth0 (wired) and eth1 (wireless).
eth0 = dbus.Interface(bus.get_object(item, eth0_path), interface)
if eth0.getLinkActive(): print('The wired network is up') # getLinkActive() is a boolean, TRUE if the network link is active
eth1 = dbus.Interface(bus.get_object(item, eth1_path), interface)
if eth1.getLinkActive(): print('The wireless network is up')
This shell script does exactly the same thing, using the same DBus call:# This shell script checks Network Manager if the network is up, using dbus as the communications medium. # There are two possible network interfaces: eth0 (wired) and eth1 (wireless). Of course, you may need to alter these to meet your own circumstances. # The basic format of dbus-send is: dbus-send --system --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager/Devices/eth0 --print-reply org.freedesktop.NetworkManager.Devices.eth0.getLinkActive DEST='org.freedesktop.NetworkManager' PPATH='/org/freedesktop/NetworkManager/Devices' DEVICE='org.freedesktop.NetworkManager.Devices' result_eth0=`dbus-send --system --dest=$DEST $PPATH'/eth0' --print-reply $DEVICE'.eth0.getLinkActive'` shaved_eth0=`echo $result_eth0 | cut -d ' ' -f8` if [ $shaved_eth0 = 'true' ]; then echo 'The wired network is up'; fi result_eth1=`dbus-send --system --dest=$DEST $PPATH'/eth1' --print-reply $DEVICE'.eth1.getLinkActive'` shaved_eth1=`echo $result_eth1 | cut -d ' ' -f8` if [ $shaved_eth1 = 'true' ]; then echo 'The wireless network is up'; fi
import dbus
item = 'org.freedesktop.NetworkManager'
path = '/org/freedesktop/NetworkManager'
interface = item + '.Device'
network_list = []
bus = dbus.SystemBus()
# Create a Network Manager interface and get the list of network devices
event = dbus.Interface(bus.get_object(item, path), interface)
# Create an interface for each device
# Query each interface to see if it's wireless
# Query each wireless interface for the networks it sees
for device in event.getDevices():
device_interface = dbus.Interface(bus.get_object(item, device), interface)
if device_interface.getType() == 2: # 0 unknown, 1 wired, 2 wireless
network_list.extend(device_interface.getNetworks())
# Reformat the network names in the list to be more readable
if network_list:
for entry in network_list:
#print entry # String of path/to/network_name
entry_list = entry.split('/')
print entry_list[-1] # String of network_name
import dbus, gobject
from dbus.mainloop.glib import DBusGMainLoop
def print_device_strength1(*args): #Use the received signals
signal_strength = args[1]
print ('Signal Strength (Method 1): ' + str(signal_strength) + '%')
def print_device_strength2(*args, **kwargs): #Use the received signals
signal_strength = args[1]
print ('Signal Strength (Method 2): ' + str(signal_strength) + '%')
DBusGMainLoop(set_as_default=True) # Set up the event loop before connecting to the bus
bus_object = dbus.SystemBus()
# The variables you need. I used the shell command 'dbus-monitor --system' to find this information
sender = 'org.freedesktop.NetworkManager'
path = '/org/freedesktop/NetworkManager'
interface = sender
member = 'DeviceStrengthChanged'
# Method 1 - bus_object.proxy_object.connect_to_signal(method, action, filter, message_parts)
proxy_object = bus_object.get_object(sender, path)
proxy_object.connect_to_signal(member, print_device_strength1, dbus_interface = interface)
# Method 2 - bus_object.add_signal_receiver(action, [filters])
bus_object.add_signal_receiver(print_device_strength2, dbus_interface = interface, member_keyword = member)
# Start the loop
loop = gobject.MainLoop()
loop.run()
d-feet application. Useful for launching programs, opening folders and windows, and manipulating the trash. Launching a program by this method means that the the window manager launches the program, not the script or terminal, so the program can remain open after the script or terminal terminates.#!/usr/bin/env python
import dbus
item = ('org.xfce.Thunar')
path = ('/org/xfce/FileManager')
interface = ('org.xfce.FileManager')
event = dbus.Interface(dbus.SessionBus().get_object(item, path), interface)
# These three lines at the end of the script open the file's 'properties' window
display = (':0') # The current session screen
uri = ('/home/me/dbus_test.py')
event.DisplayFileProperties(uri, display)
# These three lines at the end of the script launch a new application
display = (':0') # The current session screen
uri = ('/usr/bin/gftp-gtk')
event.Launch(uri, display)
# These four lines at the end of the script open a folder window and optionally select a file
display = (':0') # The current session screen
uri = ('/home/me/.cron')
filename = ('anacrontab.daily')
event.DisplayFolderAndSelect(uri, filename, display)
#!/usr/bin/python
"""This python 2.5 script uses dbus to check if the lid switch is open.
Based on an original python script at http://schurger.org/wordpress/?p=49"""
import dbus
dest = 'org.freedesktop.Hal'
hal_path = '/org/freedesktop/Hal/Manager'
hal_interface = 'org.freedesktop.Hal.Manager'
udi_interface = 'org.freedesktop.Hal.Device'
# Get the list of possible input switches. The return is a list of paths.
bus = dbus.SystemBus()
hal = dbus.Interface(bus.get_object(dest, hal_path), hal_interface)
list_of_udi_paths = hal.FindDeviceByCapability('input.switch')
# Filter the list for the word 'lid'. Print the status for each one.
for udi_path in list_of_udi_paths:
udi = dbus.Interface(bus.get_object(dest, udi_path), udi_interface)
if udi.GetProperty('button.type') == "lid":
# The button.state.value is FALSE if the lid is open.
if udi.GetProperty('button.state.value'): print ('Lid is closed')
else: print ('Lid is open')
else: print ('Problem: I could not find the lid switch. Sorry.')
/etc/dbus-1/system.d and /session.d directories.Launch method, seemingly for launching items in the terminal (source code). I can see how that would be handy, but I couldn't get it to work..odt files are actually containers (you can see one using unzip -l document.odt). Within the container, content is in the content.xml file. Script info source
Here's what I've figured out about opening, modifying, and saving the content of an .odt file:
# bash
$unzip path/container.odt content.xml
$unzip path/container.odt content.xml -d working/dir/path/
# -d places content.xml in a different directory.
# Creates a content.xml file where you want it.
# python
>>>import zipfile
>>>odt_file = zipfile.ZipFile('path/to/file.odt','a')
>>> # Options are 'r'ead only, 'w'rite only, and 'a'ppend to existing
>>>raw_xml = odt_file.read('content.xml')
>>> # Reads content.xml in as a string, doesn't place a file.
content.xml file by hand, or using a script, or using Python.>>> # Tip for using python: ElementTree is good at XML, and it can parse a file, but it cannot parse a string! >>> # So here's how to make a string look like a file using python's StringIO module. >>>import StringIO, xml.etree.ElementTree as ET >>>fakefile = StringIO.StringIO(raw_xml) # Pretend raw_xml string is a file called fakefile >>>tree = ET.parse(fakefile).getroot() # Parse the fakefile >>>fakefile.close() # close() is desired by StringIO to free the buffer >>> # Make changes to your tree here.
# bash
zip -j path/container.odt working/dir/path/content.xml
# The -j flag adds the file 'content.xml' instead of the useless 'path/content.xml'. You need this!
rm working/dir/path/content.xml # Clean up
# python
>>>new_xml = ET.tostring(tree) # If you're exporting from an ElementTree
>>>odt_file.writestr('content.xml', new_xml)
>>>odt_file.close()
cd path/to/working/directory cp path/to/template_filename.odt working_file.odt unzip working_file.odt content.xml # Change the xml...somehow zip -j working_file.odt content.xml rm content.xml
def edit_the_odt_content(template_filename):
"""Exposes the content of an .odt file so you can modify it."""
import os, shutil, StringIO, zipfile, xml.etree.ElementTree as ET
shutil.copyfile(template_filename, 'working_file.odt') # Copy the template into a working file
odt_file = zipfile.ZipFile('working_file.odt','a')
xml_string = odt_file.read('content.xml') # Read the zipped content.xml within the .odt as a string
raw_xml = StringIO.StringIO(xml_string) # Pretend the read string is a file so ElementTree will parse it
tree = ET.parse(raw_xml).getroot() # Convert raw string to ElementTree
raw_xml.close()
office_namespace = '{urn:oasis:names:tc:opendocument:xmlns:office:1.0}'
body = tree.find(office_namespace + 'body') # Search the tree to find the elements you want to change
text = body.find(office_namespace + 'text')
new_text = your_function_to_modify_the_xml(text) # You can now change the XML any way you wish
body.remove(text) # Replace the old XML with the new
body.append(new_text)
new_xml = ET.tostring(tree) # Convert the modified ElementTree back into an XML string
odt_file.writestr('content.xml', new_xml) # Write the string into the zipped content.xml
odt_file.close() # Close the zip archive (important!)
return
zip -m flag! It looks handy, claiming to delete the content.xml file from your file system after adding it to the archive...but instead it will unpredictably delete without adding to the archive.Trying to adapt the Linux-built rental invoice script onto the Windows XP bookkeeping computer
cmd - run this command at the run prompt to get a windows command line. C:\Python26\python - run python from the windows command line. C:\Python26\python "C:\Documents and Settings\All Users\Documents\" - run the script from the command line
The following python 2.x script shows your current (GPS-enabled) location on a Google Map. A useful learning experience:
#!/usr/bin/env python
"""This is a python 2.5 script that plot's a GPS receiver's location on the
Google Maps website.
In order to work, you need a network connection, an attached GPS receiver, and
the GPS daemon (gpsd).
"""
import os
#import subprocess and SU
import gps
import dbus
import sys
def test( ):
""" Step 1: Test for the existence of a running gpsd, test for the existence of an open network connection, and test for a firefox process.
If any fail, give an error message, don't try to recover. FUTURE: Could also use DBus to test for firefox and gpsd."""
process_list = os.popen('ps -e') # os.popen is deprecated in favort of subprocess.Popen
#process_list = SU.Popen(['ps','e'], stdout=SU.PIPE).stdout.read()
gpsd_existence_flag = 0
firefox_existence_flag = 0
for line in process_list.readlines():
if line.count('gpsd') > 0: gpsd_existence_flag = 1
if line.count('firefox') > 0: firefox_existence_flag = 1
if not gpsd_existence_flag:
print ("gpsd is not running. Use 'gpsd -b /dev/ttyUSB0' to start it, and then try again.")
sys.exit()
else: print ('Checking...found gpsd')
if not firefox_existence_flag:
print ("firefox is not running. Please start it and try again.")
sys.exit()
else: print ('Checking...found firefox')
bus = dbus.SystemBus()
nm_item = ('org.freedesktop.NetworkManager') # This string gets used a lot
nm_path = ('/org/freedesktop/NetworkManager')
nm_device = ('org.freedesktop.NetworkManager.Device')
list_of_interface_paths = dbus.Interface(bus.get_object(nm_item, nm_path), nm_device).getDevices()
found_network_flag = 0
for interface_path in list_of_interface_paths:
one_interface = dbus.Interface(bus.get_object(nm_item, interface_path), nm_device)
if one_interface.getLinkActive(): # True if there is an active network on this interface
if one_interface.getType() == 2: # 0 unknown, 1 wired, 2 wireless
print('Checking...found the wireless network')
found_network_flag = 1
elif one_interface.getType() == 1:
print('Checking...found the wired network')
found_network_flag = 1
if found_network_flag: return
else:
print ("cannot find a network connection. Please connect and try again.")
sys.exit()
def get_position_fix( ):
"""Step 2: Get a position fix from gpsd."""
session = gps.gps('localhost','2947') # Open a connection to gpsd
session.query('p') # Get the location fix
lat = session.fix.latitude
lon = session.fix.longitude
print ('Location is ' + str(lat) + ' latitude and ' + str(lon) + ' longitude.')
return (lat, lon)
def show_map(lat_lon_tuple):
"""Step 3: Submit the position fix to Google Maps. Note that the parentheses '()' in the URL must be escaped '\' to work.
Sample URL format: http://maps.google.com/maps?q=37.771008,+-122.41175+(You+can+insert+your+text+here)&iwloc=A&hl=en"""
url_string = ('http://maps.google.com/maps?q=' + str(lat_lon_tuple[0]) + ',+' + str(lat_lon_tuple[1]) + '+\(You+Are+Here\)&iwloc=A&hl=en')
os.popen('firefox ' + url_string)
return
# Run this script as a standalone program
if __name__ == "__main__" :
test()
location = get_position_fix()
show_map(location)
I'm experimenting with USB GPS receiver (dongle). It's a Canmore GT-730F that I received in January 2009. Here's what I've learned so far.
Manually getting data using the command line (source):
dmesg, the kernel log, to find out where the device has been mounted. In my case, it mounts reliably to /dev/ttyUSB0. If it doesn't mount, try the command sudo modprobe pl2303 to load the correct USB driver.stty command: stty 4800 > /dev/ttyUSB0cat command: cat /dev/ttyUSB0The Linux GPS Daemon (gpsd) is the central clearinghouse for receiving GPS data from the receiver, buffering it, and forwarding it to the applications that want it. gpsd has features to broadcast to dbus (system bus), update ntpd, and respond to a multitude of specific queries from clients. References: Project home page, gpsd man page, and a great example program
$sudo apt-get install gpsd gpsd-clients # Installs the daemon (gpsd) and test set (gpsd-clients) packages $gpsd -b /dev/ttyUSB0 # Start gpsd, telling it where to find the receiver $cgps # Current satellite data - great way to test that the receiver and gpsd are working
gpsfake is a gpsd simulator. It tricks gpsd into reading from a logfile instead of a real GPS device. Very handy for testing without actually using a GPS dongle. It is included with the gpsd package, and has a man page for additional reference. To make a logfile, and then to use gpsfake:
$cat /dev/ttyUSB0 > path/to/testlog # Create the log file. Use CTRL+C to end the capture. $gpsfake path/to/testlog # Run gpsd simulator (not a daemon - it will occupy the terminal)
Python interface to gpsd (python-gps) is a programming tool to build your own gps-aware application.
>>>import gps # Load the module
>>>session = gps.gps('localhost','2947') # Open a connection to gpsd
>>>session.query('o') # See man gpsd(8) for the list of commands
>>>print session.fix.latitude # Query responses are attributes of the session
>>>dir(session) # To see the possible responses
>>>del session # Close the connection to gpsdIn this case, it seems that I need a periodic session.query('p'), which just gives lat/lon and timestamp.
Time might be an issue, since the system and the GPS may think the time is different. To see if it's an issue, compare them using the python script below. In my tests, they vary from 0.08 to 1.3 seconds apart, not enough to worry about. GPS timestamps use GMT, not localtime.
#!/usr/bin/env python
import calendar, time, gps
system_time = calendar.timegm(time.gmtime()) # System time (in seconds)
session = gps.gps('localhost','2947') # Open a connection to gpsd
session.query('p') # See man gpsd(8) for the list of commands
gps_time = session.timings.c_recv_time # GPS time (in seconds)
print ('The time difference is ' + str(system_time - gps_time) + ' seconds.')MGRS (military map coordinates) conversion to/from latitude and longitude is not currently available in Ubuntu...that I can find. The dongle documentation doesn't mention MGRS at all. An online converter is available. The proj package looks promising, but I haven't figured it out yet. Perhaps Lat/Lon -> UTM -> MGRS?
DBus access appears to be undocumented...but there are tantalizing hints on Google that examples are out there. I can listen to dBus using cgps to make traffic, then dbus-monitor --system to see it.
The best storage format for tracklogs, routes, and waypoints seems to be GPX format, since it's easy to understand and cgpxlogger, included with gpsd, will create an XML track in GPX 1.1 format. Google's KML is more powerful, but also much more complex. GPSbabel universal data translator is a command-line application that translates one file type to another, and does convert GPX <-> KML.
$cgpxlogger -i 30 > path/to/logfile # Save data every 30 seconds to an XML file $gpsbabel -i gpx -f path/to/gpx_file -x duplicate -o kml -F path/to/kml_file $#gpsbabel [options] -i INTYPE -f INFILE -x FILTER -o OUTTYPE -F OUTFILE
GPSdrive navigation system looks cool, but I couldn't get maps to load, so it's utility was limited. However, it seems that online plotting of tracklogs, routes, and waypoints is possible on Google Maps (and Yahoo Maps, and others). One example is the cool GPS Visualizer.
Gypsy is an alternative daemon, but not currently in Debian or Ubuntu, so I haven't tried it. Last release 0.6 in March 2008.
GPSman device manager is an app I know nothing about. I couldn't get it to work, so I removed it. The dongle seems small enough and simple enough that it may not need to be 'managed' at all.
A quick python 2,x script to copy, unzip, and uniformly reformat the XML of an .odt file. It adds indentations and line breaks. Useful to debug my invoicing script, which muddles with the xml files, by making the files diff-able and easier to read and easier to search.
#!/usr/bin/env python
import os
import xml.etree.ElementTree as ET
odt_path_and_file = 'path/to/file.odt'
# This function was copied from http://effbot.org/zone/element-lib.htm
def indent(elem, level=0):
i = "\n" + level*" "
if len(elem):
if not elem.text or not elem.text.strip():
elem.text = i + " "
if not elem.tail or not elem.tail.strip():
elem.tail = i
for elem in elem:
indent(elem, level+1)
if not elem.tail or not elem.tail.strip():
elem.tail = i
else:
if level and (not elem.tail or not elem.tail.strip()):
elem.tail = i
odt_filename = odt_path_and_file.split('/')[-1]
folder_name = ('Desktop/' + odt_path_and_file.split('/')[-1].rstrip('.odt'))
os.popen('rm -r ' + folder_name) #Delete any old working files
os.popen('mkdir ' + folder_name)
os.popen('cp ' + odt_path_and_file + ' ' + folder_name)
os.popen('unzip ' + folder_name + '/' + odt_filename + ' -d ' + folder_name)
reply = os.popen('ls ' + folder_name)
file_list = [filename.rstrip('\n') for filename in reply.readlines() if filename.count('.xml') > 0]
for file in file_list:
print ('Parsing ' + folder_name + '/' + file)
tree = ET.parse(folder_name + '/' + file)
indent(tree.getroot())
tree.write(folder_name + '/' + file)
print ('Completed ' + file)
A quick python script to copy, unzip, and reformat an .odt file. It adds indentations and line breaks. Useful to debug my invoicing script, which muddles with the xml files, by making the files diff-able and easier to read and easier to search.
#!/usr/bin/env python
import os
import xml.etree.ElementTree as ET
odt_path_and_file = 'path/to/file.odt'
# This function was copied from http://effbot.org/zone/element-lib.htm
def indent(elem, level=0):
i = "\n" + level*" "
if len(elem):
if not elem.text or not elem.text.strip():
elem.text = i + " "
if not elem.tail or not elem.tail.strip():
elem.tail = i
for elem in elem:
indent(elem, level+1)
if not elem.tail or not elem.tail.strip():
elem.tail = i
else:
if level and (not elem.tail or not elem.tail.strip()):
elem.tail = i
odt_filename = odt_path_and_file.split('/')[-1]
folder_name = ('Desktop/' + odt_path_and_file.split('/')[-1].rstrip('.odt'))
os.popen('rm -r ' + folder_name) #Delete any old working files
os.popen('mkdir ' + folder_name)
os.popen('cp ' + odt_path_and_file + ' ' + folder_name)
os.popen('unzip ' + folder_name + '/' + odt_filename + ' -d ' + folder_name)
reply = os.popen('ls ' + folder_name)
file_list = [filename.rstrip('\n') for filename in reply.readlines() if filename.count('.xml') > 0]
for file in file_list:
print ('Parsing ' + folder_name + '/' + file)
tree = ET.parse(folder_name + '/' + file)
indent(tree.getroot())
tree.write(folder_name + '/' + file)
print ('Completed ' + file)
Our old copy of Appleworks from a previous Mac is sputtering and becoming unreliable in 10.5, so I'm looking for a replacement. OpenOffice and AbiWord are cluttered and unpleasant (spouse dislikes them), but Bean seems pleasant enough to fit our needs. Happily, it reads and writes simple documents to .rtf, .doc, and .odt.
logger is a simple command to write a string to /var/log/syslog. For example:
$ logger -i "This is a test string"
$ logger -is -p local0.info -f /var/log/syslog This is another test string
-i includes the PID
-s sends a copy to stdout (the screen)
-p is the priority. See the available priorities at 'man logger'
-f is the log to append toAnd here's how to log from a crontab:* * * * * /usr/bin/logger -i crontab test
Cron is a great way to run recurring jobs. But some jobs need to run weekly...and sometimes the computer is turned off, so the cron job doesn't run. So I'm going to migrate some jobs to anacron. Cron runs once each minute, checking if the time matches anything in the crontab list. Anacron, however, runs once each hour (triggered by cron, restart, or resume) and checks the interval in days since a job was last run.
Tips
/var/spool/anacron/JOBNAME. This is handy to change while testing.There are two ways to run a command using anacron. You can place the command directly in the anacrontab (/etc/anacrontab), or you can put a script in one of the periodic folders (/etc/cron.daily, /etc/cron.weekly, or /etc/cron.monthly)Here are some examples:
# min hr dom mon dow command 25 07 * * * date > /home/YOUR_USERNAME/.cron/test_file_1
/etc/anacrontab entry runs each time anacron is called (days = 0), which is very useful for testing. Start anacron manually with sudo anacron -d.#days delay jobname command 0 0 anacron-test2 date > /tmp/crontab-test-ouput-everytime
/etc/anacrontab entry runs once daily (days = 1), no matter how many times anacron is called automatically or manually.#days delay jobname command 1 0 anacron-test3 date >> /tmp/crontab-test-output-daily
I successfully tested a web scraper in python. It scrapes about 20 web pages for the prices of violin strings, then puts the prices in an OpenOffice document for handy printing. It is structured so I can add other output formats, and I could add an XML file to track prices over time or just print changes.
I'm installing it on the store iMac, and setting it as a daily recurring job. The finished file just pops onto the desktop, marked with the date.
A future version may compare prices from multiple sites.
The script and template live in the standard location for user scripts, /Users/username/Library/Scripts/scriptname/