Monday
Feb162009

Let your dog Twitter with TwitPic, Perl, and Motion

Update: I guess I should give her twitter account huh? It's Twitter.com/Bailey_Boo_Bag

About a week ago or so my girlfriend Kim decided to create a Twitter account for our dog Bailey. She's been updating it and occasionally, I'll update it, but I didn't really want to update two Twitter accounts, so I decided to figure out a way to let Bailey Twitter herself. I wanted Bailey to be able to upload pictures and messages when she moves around the house. I have a webcam that I don't use very often, so I decided to write a perl script that would upload pictures to TwitPic.com and update Twitter with the TwitPic link. I also wanted this to be triggered from motion detection, so I also decided to use a great Linux application appropriately named Motion, but I digress.

First the perl script. I decided to make the act of uploading the picture and updating Twitter it's own self contained script so it could be used on it's own or for other things and it works on Windows, Linux, and Mac.

Download the script here

You can set default values in the script and then all you need to do is pass in a picture, or you can use the command line options to override all the options. I set up defaults for everything, and have been just calling the script with the --picture option and the --message option.

 Now all you need to do is set up your webcam application. As I said, I used Motion, so I'll show you how to set that up, but I'm sure you could do this with WebCamXP or something. From the command line do the following:

  1. sudo apt-get install motion
  2. mkdir ~/.motion
  3. sudo cp /etc/motion/motion.conf ~/.motion
  4. sudo chown $USER ~/.motion/motion.conf
  5. vim ~/.motion/motion.conf


Then you can just edit the conf to your liking. You can enable/disable things, capture movies, and a ton of other stuff that I don't really know much about. Or you can just copy and paste my config. I turned off the webserver and tweaked a few other things, but most of the stuff is the same. The one key line, is the line that calls the updateTwitter.pl script. My settings assume that your script is located at
~/motion/updateTwitter.pl.

 

# Rename this distribution example file to motion.conf
#
# This config file was generated by motion 3.2.9

############################################################
# Daemon
############################################################

# Start in daemon (background) mode and release terminal (default: off)
daemon off

# File to store the process ID, also called pid file. (default: not defined)
process_id_file /var/run/motion.pid

############################################################
# Basic Setup Mode
############################################################

# Start in Setup-Mode, daemon disabled. (default: off)
setup_mode off

###########################################################
# Capture device options
############################################################

# Videodevice to be used for capturing (default /dev/video0)
# for FreeBSD default is /dev/bktr0
videodevice /dev/video0

# Tuner device to be used for capturing using tuner as source (default /dev/tuner0)
# This is ONLY used for FreeBSD. Leave it commented out for Linux
; tunerdevice /dev/tuner0

# The video input to be used (default: 8)
# Should normally be set to 1 for video/TV cards, and 8 for USB cameras
input 8

# The video norm to use (only for video capture and TV tuner cards)
# Values: 0 (PAL), 1 (NTSC), 2 (SECAM), 3 (PAL NC no colour). Default: 0 (PAL)
norm 0

# The frequency to set the tuner to (kHz) (only for TV tuner cards) (default: 0)
frequency 0

# Rotate image this number of degrees. The rotation affects all saved images as
# well as mpeg movies. Valid values: 0 (default = no rotation), 90, 180 and 270.
rotate 0

# Image width (pixels). Valid range: Camera dependent, default: 352
width 640

# Image height (pixels). Valid range: Camera dependent, default: 288
height 480

# Maximum number of frames to be captured per second.
# Valid range: 2-100. Default: 100 (almost no limit).
framerate 100

# Minimum time in seconds between capturing picture frames from the camera.
# Default: 0 = disabled - the capture rate is given by the camera framerate.
# This option is used when you want to capture images at a rate lower than 2 per second.
minimum_frame_time 0

# URL to use if you are using a network camera, size will be autodetected (incl http:// ftp:// or file:///)
# Must be a URL that returns single jpeg pictures or a raw mjpeg stream. Default: Not defined
; netcam_url value

# Username and password for network camera (only if required). Default: not defined
# Syntax is user:password
; netcam_userpass value

# URL to use for a netcam proxy server, if required, e.g. "http://myproxy".
# If a port number other than 80 is needed, use "http://myproxy:1234".
# Default: not defined
; netcam_proxy value

# Let motion regulate the brightness of a video device (default: off).
# The auto_brightness feature uses the brightness option as its target value.
# If brightness is zero auto_brightness will adjust to average brightness value 128.
# Only recommended for cameras without auto brightness
auto_brightness off

# Set the initial brightness of a video device.
# If auto_brightness is enabled, this value defines the average brightness level
# which Motion will try and adjust to.
# Valid range 0-255, default 0 = disabled
brightness 0

# Set the contrast of a video device.
# Valid range 0-255, default 0 = disabled
contrast 0

# Set the saturation of a video device.
# Valid range 0-255, default 0 = disabled
saturation 0

# Set the hue of a video device (NTSC feature).
# Valid range 0-255, default 0 = disabled
hue 0

############################################################
# Round Robin (multiple inputs on same video device name)
############################################################

# Number of frames to capture in each roundrobin step (default: 1)
roundrobin_frames 1

# Number of frames to skip before each roundrobin step (default: 1)
roundrobin_skip 1

# Try to filter out noise generated by roundrobin (default: off)
switchfilter off

############################################################
# Motion Detection Settings:
############################################################

# Threshold for number of changed pixels in an image that
# triggers motion detection (default: 1500)
threshold 1500

# Automatically tune the threshold down if possible (default: off)
threshold_tune off

# Noise threshold for the motion detection (default: 32)
noise_level 32

# Automatically tune the noise threshold (default: on)
noise_tune on

# Enables motion to adjust its detection/noise level for very dark frames
# Don't use this with noise_tune on. (default: off)
night_compensate off

# Despeckle motion image using (e)rode or (d)ilate or (l)abel (Default: not defined)
# Recommended value is EedDl. Any combination (and number of) of E, e, d, and D is valid.
# (l)abeling must only be used once and the 'l' must be the last letter.
# Comment out to disable
despeckle EedDl

# PGM file to use as a sensitivity mask.
# Full path name to. (Default: not defined)
; mask_file value

# Dynamically create a mask file during operation (default: 0)
# Adjust speed of mask changes from 0 (off) to 10 (fast)
smart_mask_speed 0

# Ignore sudden massive light intensity changes given as a percentage of the picture
# area that changed intensity. Valid range: 0 - 100 , default: 0 = disabled
lightswitch 0

# Picture frames must contain motion at least the specified number of frames
# in a row before they are detected as true motion. At the default of 1, all
# motion is detected. Valid range: 1 to thousands, recommended 1-5
minimum_motion_frames 1

# Specifies the number of pre-captured (buffered) pictures from before motion
# was detected that will be output at motion detection.
# Recommended range: 0 to 5 (default: 0)
# Do not use large values! Large values will cause Motion to skip video frames and
# cause unsmooth mpegs. To smooth mpegs use larger values of post_capture instead.
pre_capture 0

# Number of frames to capture after motion is no longer detected (default: 0)
post_capture 0

# Gap is the seconds of no motion detection that triggers the end of an event
# An event is defined as a series of motion images taken within a short timeframe.
# Recommended value is 60 seconds (Default). The value 0 is allowed and disables
# events causing all Motion to be written to one single mpeg file and no pre_capture.
gap 60

# Maximum length in seconds of an mpeg movie
# When value is exceeded a new mpeg file is created. (Default: 0 = infinite)
max_mpeg_time 0

# Number of frames per second to capture when not detecting
# motion (saves CPU load) (Default: 0 = disabled)
low_cpu 0

# Always save images even if there was no motion (default: off)
output_all off

############################################################
# Image File Output
############################################################

# Output 'normal' pictures when motion is detected (default: on)
# Valid values: on, off, first, best
# When set to 'first', only the first picture of an event is saved.
# Picture with most motion of an event is saved when set to 'best'.
# Can be used as preview shot for the corresponding movie.
output_normal on

# Output pictures with only the pixels moving object (ghost images) (default: off)
output_motion off

# The quality (in percent) to be used by the jpeg compression (default: 75)
quality 100

# Output ppm images instead of jpeg (default: off)
ppm off

############################################################
# FFMPEG related options
# Film (mpeg) file output, and deinterlacing of the video input
# The options movie_filename and timelapse_filename are also used
# by the ffmpeg feature
############################################################

# Use ffmpeg to encode mpeg movies in realtime (default: off)
ffmpeg_cap_new off

# Use ffmpeg to make movies with only the pixels moving
# object (ghost images) (default: off)
ffmpeg_cap_motion off

# Use ffmpeg to encode a timelapse movie
# Default value 0 = off - else save frame every Nth second
ffmpeg_timelapse 0

# The file rollover mode of the timelapse video
# Valid values: hourly, daily (default), weekly-sunday, weekly-monday, monthly, manual
ffmpeg_timelapse_mode daily

# Bitrate to be used by the ffmpeg encoder (default: 400000)
# This option is ignored if ffmpeg_variable_bitrate is not 0 (disabled)
ffmpeg_bps 500000

# Enables and defines variable bitrate for the ffmpeg encoder.
# ffmpeg_bps is ignored if variable bitrate is enabled.
# Valid values: 0 (default) = fixed bitrate defined by ffmpeg_bps,
# or the range 2 - 31 where 2 means best quality and 31 is worst.
ffmpeg_variable_bitrate 0

# Codec to used by ffmpeg for the video compression.
# Timelapse mpegs are always made in mpeg1 format independent from this option.
# Supported formats are: mpeg1 (ffmpeg-0.4.8 only), mpeg4 (default), and msmpeg4.
# mpeg1 - gives you files with extension .mpg
# mpeg4 or msmpeg4 - give you files with extension .avi
# msmpeg4 is recommended for use with Windows Media Player because
# it requires no installation of codec on the Windows client.
# swf - gives you a flash film with extension .swf
# flv - gives you a flash video with extension .flv
# ffv1 - FF video codec 1 for Lossless Encoding ( experimental )
ffmpeg_video_codec swf

# Use ffmpeg to deinterlace video. Necessary if you use an analog camera
# and see horizontal combing on moving objects in video or pictures.
# (default: off)
ffmpeg_deinterlace off

############################################################
# Snapshots (Traditional Periodic Webcam File Output)
############################################################

# Make automated snapshot every N seconds (default: 0 = disabled)
snapshot_interval 0

############################################################
# Text Display
# %Y = year, %m = month, %d = date,
# %H = hour, %M = minute, %S = second, %T = HH:MM:SS,
# %v = event, %q = frame number, %t = thread (camera) number,
# %D = changed pixels, %N = noise level, \n = new line,
# %i and %J = width and height of motion area,
# %K and %L = X and Y coordinates of motion center
# %C = value defined by text_event - do not use with text_event!
# You can put quotation marks around the text to allow
# leading spaces
############################################################

# Locate and draw a box around the moving object.
# Valid values: on, off and preview (default: off)
# Set to 'preview' will only draw a box in preview_shot pictures.
locate off

# Draws the timestamp using same options as C function strftime(3)
# Default: %Y-%m-%d\n%T = date in ISO format and time in 24 hour clock
# Text is placed in lower right corner
text_right %Y-%m-%d\n%T-%q

# Draw a user defined text on the images using same options as C function strftime(3)
# Default: Not defined = no text
# Text is placed in lower left corner
text_left "Living Room"

# Draw the number of changed pixed on the images (default: off)
# Will normally be set to off except when you setup and adjust the motion settings
# Text is placed in upper right corner
text_changes off

# This option defines the value of the special event conversion specifier %C
# You can use any conversion specifier in this option except %C. Date and time
# values are from the timestamp of the first image in the current event.
# Default: %Y%m%d%H%M%S
# The idea is that %C can be used filenames and text_left/right for creating
# a unique identifier for each event.
; text_event %Y%m%d%H%M%S

# Draw characters at twice normal size on images. (default: off)
text_double on

############################################################
# Target Directories and filenames For Images And Films
# For the options snapshot_, jpeg_, mpeg_ and timelapse_filename
# you can use conversion specifiers
# %Y = year, %m = month, %d = date,
# %H = hour, %M = minute, %S = second,
# %v = event, %q = frame number, %t = thread (camera) number,
# %D = changed pixels, %N = noise level,
# %i and %J = width and height of motion area,
# %K and %L = X and Y coordinates of motion center
# %C = value defined by text_event
# Quotation marks round string are allowed.
############################################################

# Target base directory for pictures and films
# Recommended to use absolute path. (Default: current working directory)
target_dir .

# File path for snapshots (jpeg or ppm) relative to target_dir
# Default: %v-%Y%m%d%H%M%S-snapshot
# Default value is equivalent to legacy oldlayout option
# For Motion 3.0 compatible mode choose: %Y/%m/%d/%H/%M/%S-snapshot
# File extension .jpg or .ppm is automatically added so do not include this.
# Note: A symbolic link called lastsnap.jpg created in the target_dir will always
# point to the latest snapshot, unless snapshot_filename is exactly 'lastsnap'
snapshot_filename %v-%Y%m%d%H%M%S-snapshot

# File path for motion triggered images (jpeg or ppm) relative to target_dir
# Default: %v-%Y%m%d%H%M%S-%q
# Default value is equivalent to legacy oldlayout option
# For Motion 3.0 compatible mode choose: %Y/%m/%d/%H/%M/%S-%q
# File extension .jpg or .ppm is automatically added so do not include this
# Set to 'preview' together with best-preview feature enables special naming
# convention for preview shots. See motion guide for details
jpeg_filename %v-%Y%m%d%H%M%S-%q

# File path for motion triggered ffmpeg films (mpeg) relative to target_dir
# Default: %v-%Y%m%d%H%M%S
# Default value is equivalent to legacy oldlayout option
# For Motion 3.0 compatible mode choose: %Y/%m/%d/%H%M%S
# File extension .mpg or .avi is automatically added so do not include this
# This option was previously called ffmpeg_filename
movie_filename %v-%Y%m%d%H%M%S

# File path for timelapse mpegs relative to target_dir
# Default: %Y%m%d-timelapse
# Default value is near equivalent to legacy oldlayout option
# For Motion 3.0 compatible mode choose: %Y/%m/%d-timelapse
# File extension .mpg is automatically added so do not include this
timelapse_filename %Y%m%d-timelapse

############################################################
# Live Webcam Server
############################################################

# The mini-http server listens to this port for requests (default: 0 = disabled)
webcam_port 0

# Quality of the jpeg images produced (default: 50)
webcam_quality 50

# Output frames at 1 fps when no motion is detected and increase to the
# rate given by webcam_maxrate when motion is detected (default: off)
webcam_motion off

# Maximum framerate for webcam streams (default: 1)
webcam_maxrate 1

# Restrict webcam connections to localhost only (default: on)
webcam_localhost on

# Limits the number of images per connection (default: 0 = unlimited)
# Number can be defined by multiplying actual webcam rate by desired number of seconds
# Actual webcam rate is the smallest of the numbers framerate and webcam_maxrate
webcam_limit 0

############################################################
# HTTP Based Control
############################################################

# TCP/IP port for the http server to listen on (default: 0 = disabled)
control_port 0

# Restrict control connections to localhost only (default: on)
control_localhost on

# Output for http server, select off to choose raw text plain (default: on)
control_html_output on

# Authentication for the http based control. Syntax username:password
# Default: not defined (Disabled)
; control_authentication username:password

############################################################
# Tracking (Pan/Tilt)
############################################################

# Type of tracker (0=none (default), 1=stepper, 2=iomojo, 3=pwc, 4=generic, 5=uvcvideo)
# The generic type enables the definition of motion center and motion size to
# be used with the conversion specifiers for options like on_motion_detected
track_type 0

# Enable auto tracking (default: off)
track_auto off

# Serial port of motor (default: none)
; track_port value

# Motor number for x-axis (default: -1)
track_motorx -1

# Motor number for y-axis (default: -1)
track_motory -1

# Maximum value on x-axis (default: 0)
track_maxx 0

# Maximum value on y-axis (default: 0)
track_maxy 0

# ID of an iomojo camera if used (default: 0)
track_iomojo_id 0

# Angle in degrees the camera moves per step on the X-axis
# with auto-track (default: 10)
# Currently only used with pwc type cameras
track_step_angle_x 10

# Angle in degrees the camera moves per step on the Y-axis
# with auto-track (default: 10)
# Currently only used with pwc type cameras
track_step_angle_y 10

# Delay to wait for after tracking movement as number
# of picture frames (default: 10)
track_move_wait 10

# Speed to set the motor to (stepper motor option) (default: 255)
track_speed 255

# Number of steps to make (stepper motor option) (default: 40)
track_stepsize 40

############################################################
# External Commands, Warnings and Logging:
# You can use conversion specifiers for the on_xxxx commands
# %Y = year, %m = month, %d = date,
# %H = hour, %M = minute, %S = second,
# %v = event, %q = frame number, %t = thread (camera) number,
# %D = changed pixels, %N = noise level,
# %i and %J = width and height of motion area,
# %K and %L = X and Y coordinates of motion center
# %C = value defined by text_event
# %f = filename with full path
# %n = number indicating filetype
# Both %f and %n are only defined for on_picture_save,
# on_movie_start and on_movie_end
# Quotation marks round string are allowed.
############################################################

# Do not sound beeps when detecting motion (default: on)
# Note: Motion never beeps when running in daemon mode.
quiet on

# Command to be executed when an event starts. (default: none)
# An event starts at first motion detected after a period of no motion defined by gap
; on_event_start value

# Command to be executed when an event ends after a period of no motion
# (default: none). The period of no motion is defined by option gap.
; on_event_end value

# Command to be executed when a picture (.ppm|.jpg) is saved (default: none)
# To give the filename as an argument to a command append it with %f
on_picture_save perl /home/rtu/motion/updateTwitter.pl --picture %f

# Command to be executed when a motion frame is detected (default: none)
; on_motion_detected value

# Command to be executed when a movie file (.mpg|.avi) is created. (default: none)
# To give the filename as an argument to a command append it with %f
; on_movie_start value

# Command to be executed when a movie file (.mpg|.avi) is closed. (default: none)
# To give the filename as an argument to a command append it with %f
; on_movie_end value

############################################################
# Common Options For MySQL and PostgreSQL database features.
# Options require the MySQL/PostgreSQL options to be active also.
############################################################

# Log to the database when creating motion triggered image file (default: on)
sql_log_image off

# Log to the database when creating a snapshot image file (default: on)
sql_log_snapshot off

# Log to the database when creating motion triggered mpeg file (default: off)
sql_log_mpeg off

# Log to the database when creating timelapse mpeg file (default: off)
sql_log_timelapse off

# SQL query string that is sent to the database
# Use same conversion specifiers has for text features
# Additional special conversion specifiers are
# %n = the number representing the file_type
# %f = filename with full path
# Default value:
# insert into security(camera, filename, frame, file_type, time_stamp, text_event) values('%t', '%f', '%q', '%n', '%Y-%m-%d %T', '%C')
sql_query insert into security(camera, filename, frame, file_type, time_stamp, event_time_stamp) values('%t', '%f', '%q', '%n', '%Y-%m-%d %T', '%C')

############################################################
# Database Options For MySQL
############################################################

# Mysql database to log to (default: not defined)
; mysql_db value

# The host on which the database is located (default: localhost)
; mysql_host value

# User account name for MySQL database (default: not defined)
; mysql_user value

# User password for MySQL database (default: not defined)
; mysql_password value

############################################################
# Database Options For PostgreSQL
############################################################

# PostgreSQL database to log to (default: not defined)
; pgsql_db value

# The host on which the database is located (default: localhost)
; pgsql_host value

# User account name for PostgreSQL database (default: not defined)
; pgsql_user value

# User password for PostgreSQL database (default: not defined)
; pgsql_password value

# Port on which the PostgreSQL database is located (default: 5432)
; pgsql_port 5432

############################################################
# Video Loopback Device (vloopback project)
############################################################

# Output images to a video4linux loopback device
# The value '-' means next available (default: not defined)
; video_pipe value

# Output motion images to a video4linux loopback device
# The value '-' means next available (default: not defined)
; motion_video_pipe value

##############################################################
# Thread config files - One for each camera.
# Except if only one camera - You only need this config file.
# If you have more than one camera you MUST define one thread
# config file for each camera in addition to this config file.
##############################################################

# Remember: If you have more than one camera you must have one
# thread file for each camera. E.g. 2 cameras requires 3 files:
# This motion.conf file AND thread1.conf and thread2.conf.
# Only put the options that are unique to each camera in the
# thread config files.
; thread /usr/local/etc/thread1.conf
; thread /usr/local/etc/thread2.conf
; thread /usr/local/etc/thread3.conf
; thread /usr/local/etc/thread4.conf

 

This script will upload pictures very quickly to your twitter account, and spam the hell out of people when motion is found, so you'll need to adjust the frame rate/sensitivity.

Monday
Feb092009

iPhone time lapse

Because I have this ongoing obsession with time lapse, I'm always looking for more obscure ways to create time lapse video. This weeks challenge includes a little stitching (which I outlined in an earlier post), a home made iPhone stand, and an incense candle that my girlfriend likes to burn.

First I'd like to start with a quick review of the application that I used on the iPhone to capture the images appropriately named "TimeLapse". It has a standard, and fair price of .99 cents and works as advertised. It's made up of two pages that allow you to set the speed at which pictures are taken, frame your shot, and shoot your pictures. Below is a picture of the first screen you see after launching the app:

On this screen you can set the rate at which your pictures are taken, how many pictures you want to take, and what quality you want to shoot at.

I really liked everything about this app, and can really only say the one thing I didn't like was that, although you have the choice to try and take pictures every second, you can actually take pictures at about 10 second intervals. This is something the developer states upfront however, so it's hard to knock the app on that. I'm sure this is a hardware limitation anyway, so what can you do?

Now, before we get into the quick rundown on how to make the video, here is what I came up with. It's short and sweet and was really just a proof of concept.

 



 

Ok, here's what you need to do to make time lapse videos with your iPhone:

 


  1. Install the TimeLapse application on your iPhone
  2. Buy/create a tripod for your phone. I had an arm laying around from an old satellite radio, and here is what I came up with:

     

    Doing some timelapse with my iPhone

  3. After securing your iPhone to the tripod (I did this in portrait mode, but I'd do it in landscape next time), put your phone in airplane mode so you don't get a call that messes up your shot.
  4. Get plenty of lighting in place, set your timing to something reasonable (you may have to try a few times to get it just right), and then start the app
  5. After letting the app run for the desired amount of time, stop and take the phone off the tripod and head to the computer
  6. All you need to do now is plug the phone into the computer, and then access the pictures like any digital camera. On Windows, you can go to my computer, and you'll see the iPhone listed under cameras. On the Mac, you should be prompted to download them, and on Ubuntu, you'll be prompted as well.
  7. Now all you need to do is stitch the pictures together using some software like ffmpeg. You can learn how to do that here

 

Anyway, if you're ever out and about and want to make a quick time lapse, fire up your iPhone and let it run...

Wednesday
Feb042009

20,000 pixel pano

In the last few months, I've been interested in learning how to put my SLR to better use. Let's face it, 99% of the pictures I take with it are on auto. What's the point of having a an SLR if you're just using it as a point and shoot? So I read the manual and started to poke around on the net. I first wanted to do some exposure shots or maybe something with a cool blur effect. What I settled on was a night shot with some blurred lights. My Canon makes this pretty easy for beginners by including a mode called shutter priority which allows the photographer to adjust the shutter and the camera will adjust the rest (aperture, white balance, etc..) itself. This is pretty cool, because all I have to worry about is framing the shot and keeping the camera still. As you can see, I got some pretty good results:

I like this one the best

I digress however, as this post is to talk about a shot that took quite a bit longer to get together: a 20k pixel panorama of Denver's front range. Because the picture is so large, you can decide if you want to load it or not:

Panorama of the Front Range

To set this shot up, I found a high point (of which there are many around these parts), set up my tripod, and then started taking picture from left to right overlapping about 10% of each shot. At first I did this on full auto mode, but then I decided to go all manual, because the contrast varied too much between each picture which adds a lot of post processing time. After I was satisfied I had enough pictures, I headed home.

When I got home, I decided to fire up The Gimp and see what I could do. As it turns out, unlike Photoshop, The Gimp doesn't have a quick way to create panos. out of the box. Also, unlike Photoshop, The Gimp has a ton of free plug-ins that do everything you can imagine. So after about one second of Googling, I found a plug-in called Pandora. The site has the download and a easy to follow tutorial on stitching your picture together. Using the tutorial, and about a hour of my time, I figured out how to stitch these bad boys together. I even started getting "advanced" and adjusting the contrast and brightness as well as rotating and cropping.

So I was able to put together a really nice picture with about 4 hours of my time and I got some exercise to boot. Now that I have the technique down, I hope to hone my skills and I expect the next shot to look even better.

- - Rob

Monday
Jan262009

Application launchers

An application launcher is a little piece of utility software that runs in the back ground of the OS and waits for a key combination to be pressed. Once you hit that combination (say alt + space), a little window pops up that allows you to start typing. You can then type the first few letters of the app you want to launch, and then hit enter and the app will pop up. This allows you to launch apps without taking your hand off the keyboard. For people like me (who live and die by shortcuts), this is the promised land. Many of these app launchers can be configured to open folders, search the hard drive, and many more tasks with endless plug-ins.

There are a number of apps that do this, as listed on Wikipedia, but I'll talk about the three that I've used/use on a daily basis. First there's Launchy. Launchy is a free (as is freedom), utility that runs on both Windows and Linux and has plug-in support as well as configurable key combos. I use this everyday at work and have very few problems with it. The app will "learn" your favorites as you pic them out of a list, so you won't need to pick them the second time around. Some plug-ins you may be interested in are: putty integration, weby, and one I've recently started using, Google calc. From my experience, this app works as well on Linux (Ubuntu) as it does on Windows.

Next up is Quicksilver for Mac OS X. This is the best application launcher around in my opinion. It is very polished and not only searches, and launches well, but has all the visual crack you need and love on OS X. Quicksilver also supports plug-ins, and has many configurable preferences; not to mention you can tweak the look and feel.

Lastly, we have a Linux (KDE) only option known as Katapult. This is my least favorite option out of the bunch. And being a Linux hippy, I hate to admit that there is a Mac option that I like better. It works well enough, but it doesn't learn my preferences, which kind of gets annoying. It is skinable and about the same configuration options as Launchy.

Anyway, once you start using one of these fabulous applications, you'll find it painful to go back. I have one of these installed on every box that I use regularly, and I find that I can work much more efficiently.

- - Rob

Tuesday
Jan202009

Today's obscure Linux problem

With this post, I'll be taking a cue from my friend Stu over at Corrosive Content, and posting something helpful. At work I often run into obscure problems that take a lot of time to solve. Because I work on Windows, Mac, and various other Unix flavors, I get a chance to see the worst each operating system has to offer. This little "bug" is one of those neat bugs that just doesn't seem like it can actually be true.

You run a df and notice that your /tmp directory is full. No problem, just cd /tmp and then see what's in there. After listing the files, you notice that there are a lot of .shitty files in the directory and you know you can delete those. No problem, a quick rm *.shitty should do the trick...Only one problem, you run the command and you get this cute little message:

Argument list too long

What? Let's just list the files and see what this is all about: ls *.shitty

Argument list too long

You've got to be kidding right? As it turns out, there is a limited size buffer created for shell commands and rm *.shitty actually expands to rm 1.shitty 2.shitty 3.shitty, which quickly becomes too big for the command line. Here are a few options I came up with:

The simplest answer is to do something like this:

find . -name "*.shitty" | xargs rm

This doesn't work if you have spaces in the names of the .shitty files or if the .shitty files have special characters. So you should do this:

find . -name "*.shitty" -print0 | xargs -0 rm

And finally, an extra little tid bit...Say you are in a parent directory and you want to get rid of all the files in a set up children directories:

find . -wholename "*/FunctionTests/InputData/*.shitty" -print0 | xargs -0 rm

This will go through all the directories in the current directory and look for *.shitty files in the FunctionTests/InputData folders under them. The option that is special here is the -wholename option. If you try to do this with -name, you will get an error or on some versions of find, you will get unexpected results.

- - Rob