change timezone debian

# dpkg-reconfigure tzdata

increase postfix message size limit

# date | mail -a hugefile.sql fordodone@fordodone.com
# postdrop: warning: uid=0: File too large
send-mail: fatal: root(0): message file too big

# echo "message_size_limit = 102400000" >>/etc/postfix/main.cf && service postfix reload
Reloading Postfix configuration...done.
#

First install the qrencode utility:

# apt-get install -y qrencode

You can see the version:

# qrencode -V
qrencode version 3.1.1
Copyright (C) 2006, 2007, 2008, 2009 Kentaro Fukuchi

Now 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.

Start with a file that has a bunch of numbers like this:

# tail -20 filename
0
0
1
0
3
0
0
54
0
1
1
2
0
0
0
1
21
90
0
0

We want the longest streak of 0s

# awk '{if($1==0)j++;else j=0; print j}' filename | sort -nu | tail -1
7