First install the qrencode utility:
# apt-get install -y qrencodeYou can see the version:
# qrencode -V
qrencode version 3.1.1
Copyright (C) 2006, 2007, 2008, 2009 Kentaro FukuchiNow create the QR code with this string:
# qrencode -o wifi.png "WIFI:S:fordodone-wifi-ssid;T:WPA2;P:F0rd0d0n3;;"The pattern is “WIFI:S:<yournetworkssid>;T:WPA2;P:<wpa2passphrase>;;” Be sure to note the semicolons vs. colons.
Don’t exceed 9 characters on username. Seems like nick is not limited to 9 characters as RFC1459 and RFC2812 say, but usernames longer than 9 do NOT work.
Sometimes people run sshd on a non-standard port. It takes time to scan an IP block, and scanning each host for all 65,535 ports makes it take even longer. Most scanning scripts and utilities target common known open ports, like telnet, smb, and ssh. For this reason someone might opt to run sshd on a port other than 22. This is a problem if you are using git over ssh to connect to one of these repositories.
Add the follwing to your ssh config:
cat >>/home/<yourusername>/.ssh/config << EOF
Host <git server IP address>
Port <obscure sshd port number>
IdentityFile /home/<yourusername>/.ssh/id_git
EOF
I was recently handed an old Windows laptop, and told “It is broken so I know you can put it to use, and if you get my music off of it that would be awesome.” Right away I knew I had a great chance of recovering everything from the hard drive.
I took the hard drive out of the laptop and plugged it into my workstation via a SATA to USB converter. It showed right up and I mounted the partition that I thought would be the windows partition:
# ls
autoexec.bat config.sys doctemp found.000 found.003 MSOCache pagefile.sys ProgramData Program Files Users
Boot DELL Documents and Settings found.001 hiberfil.sys newfile.enc pending.un ProgramData.LOG1 $Recycle.Bin Windows
bootmgr dell.sdr Drivers found.002 Intel newkey PerfLogs ProgramData.LOG2 System Volume Information
Well, that looks familiar. Then went into the person’s user directory and did this:
# find . -type f -name '*.m4a' -o -name '*.mp3' -ls > ~/music_file_listI could have been more thorough and looked for more file extensions (acc,m4u, etc.), but I figured iTunes would just put every music file in the same folder. The resultant file looked like this:
# tail music_file_list
82837 9632 -rw------- 2 fordodone fordodone 9861791 Sep 16 2008 ./Users/laptop/Music/iTunes/Alanis\ Morissette\ -\ Jagged\ Little\ Pi\ 12.mp3
307 27696 -rw------- 2 fordodone fordodone 28357414 Oct 22 2008 ./Users/laptop/Searches/Documents/3L\ First\ Semester/Energy/dem\ now.mp3
53814 4856 -rw------- 2 fordodone fordodone 4972361 Feb 17 2007 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Bouncing\ Around\ The\ Room.mp3
53817 6116 -rw------- 2 fordodone fordodone 6259086 Feb 17 2007 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Come\ Together.mp3
53834 8132 -rw------- 2 fordodone fordodone 8325962 Feb 17 2007 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Funky\ Bitch.mp3
53962 31512 -rw------- 2 fordodone fordodone 32266213 Dec 21 2004 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Inflate-_Barnacles.mp3
53975 4424 -rw------- 2 fordodone fordodone 4527885 Feb 17 2007 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Julius.mp3
53979 12288 -rw------- 2 fordodone fordodone 12579091 Apr 1 2002 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Mike's\ Song.mp3
54019 8476 -rw------- 2 fordodone fordodone 8677963 Mar 31 2002 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Vultures.mp3
54028 6004 -rw------- 2 fordodone fordodone 6146289 Feb 17 2007 ./Users/laptop/Searches/Documents/Old\ Computer/My\ Music/01\ Wilson.mp3Now the goal was to get a list of unique directories in which music could be found. I would then take that list and rsync those directories to a local hard drive. Since the music files could be located at any unpredictable level in the tree, and I only wanted the directory listing I did this:
# cat music_file_list | cut -d / -f 2- | rev | cut -d / -f 2- | rev | sort | uniq -c
926 Users/laptop/Music/iTunes
27 Users/laptop/Music/iTunes/iTunes\ Music/Podcasts/GreenBiz\ Radio
10 Users/laptop/Music/iTunes/iTunes\ Music/Podcasts/NPR_\ Planet\ Money\ Podcast
51 Users/laptop/Music/iTunes/iTunes\ Music/Podcasts/This\ American\ Life
4 Users/laptop/Music/iTunes/iTunes\ Music/Podcasts/WNYC's\ Radiolab
2 Users/laptop/Music/iTunes/iTunes\ Music/Smeal\ College\ of\ Business/Wall\ Street\ Bootcamp\ Series
1 Users/laptop/Searches/Documents/3L\ First\ Semester/Energy
8 Users/laptop/Searches/Documents/Old\ Computer/My\ MusicThat gave me the list I was looking for and how many mp3 and m4a files were in each unique directory. I’ll probably skip the Podcasts, and just recover the rest. It looks like this will be about 30G of files, so I will probably use adrive.com to upload and share this amount of data.
TODO: revisit this exercise with awk.
Use the shred utility to wipe an old hard drive. Shred is part of the coreutils package on Linux.
# dpkg -S /usr/bin/shred
coreutils: /usr/bin/shred
To wipe /dev/sdc use this:
shred -vfz -n 20 /dev/sdcThis will overwrite the drive 20 times (-n 20), show progress (-v), force if permissions needed (-f), and overwrite the last time with zeros (-z) making it look like a blank hard drive. 20 times is way overkill, but we have to be paranoid. The average person wouldn’t be able to get past the layers of RAID1, volume encryption, lvm, and ecryptfs home dir encryption, let alone a single pass of zeros, but we want to make it more difficult for people/agencies who know what they are doing.
Find the function wp_tag_cloud in wordpress/wp-includes/category-template.php to see default array of values. For me it’s on line 531 (wp 3.3.1). The ‘number’ element sets the number of tags it will put into the cloud. Edit accordingly to increase. Here it is set to 500 elements:
'number' => 500If you need to email everyone on a project, it’s probably no big deal to find people’s account information and cut and paste into an email. But if you have hundreds of users on a project, just go to the database and get their emails. First find the project id, then get all the emails for people on that project.
mysql> select users.mail from members left join users on members.user_id = users.id where members.project_id = 14;switch> show version | include uptime
switch uptime is 1 year, 46 weeks, 5 days, 4 hours, 51 minutesIf you don’t want to loose all of your current connections, you need to get haproxy to reload the new configuration without stopping and starting.
# haproxy -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf $(cat /var/run/haproxy.pid)The -sf flag is for a soft reset.
The temperature can be read directly from a sensor on the RPi, in this file:
# cat /sys/class/thermal/thermal_zone0/temp
50306As you can see it comes in milli-degrees Celsius. Use awk to convert it to degrees:
# awk '{print $1/1000 " C"}' /sys/class/thermal/thermal_zone0/temp
50.843 C