Windows 10 "fall creators update" 2017, more precisely known as Windows 10 version 1709, brings with it a new version of the windows console.
This is the terminal that is used to display cmd.exe and PowerShell commandline environments.

Now the new version is nice, amongst other things it has is variable transparency, but it turns off processing terminal escape sequences from Python (and probably a load of other things) by default.

This is how to turn on the processing of terminal escape sequences in Win10 console V2.

Using RegEdit add "VirtualTerminalLevel" as a DWORD to ‘HKCU\Console’ set to value 0x1

I've been playing around with react-native for a week or so, and I'm liking it.
If you don't know what it is, its basically a toolkit for building mobile apps with, one that makes it easy to achieve good looking apps that integrate with your phone without you having to learn low-level details about how phones work (yay for that!).
One of the great things is that, with Android at least, you can use your own favourite editing tools and the Android SDK and react-native will build your app, install it on your phone, start it running, and attach a debugger to the app and the developer tools in your web browser.
All from one simple command:

react-native run-android

adb shell input keyevent 82 

We have just copied a big chunk of files off a broken home NAS by mounting the hdd in a windows PC. Luckily this one has a windows format partition on it, the other one doesn't so I'll need to make a bootable Linux USB dongle, probably via https://www.pendrivelinux.com/ and boot from that.

icacls .\ /reset /T /C /L

takeown.exe /F .\ /R

So these are two commands to mount shared folder in a linux host on a linux guest so that the guest has full permission in the shared folders.

This first command should be executed on the guest VM

sudo mount -t vboxsf SHARE_NAME /MOUNT_POINT/ -o rw,users,umask=0000

VBoxManage setextradata VM_NAME VBoxInternal2/SharedFoldersEnableSymlinksCreate/SHARE_NAME 1 

I have recently been messing around with a raspberry pi at work (a Pi2 model B) for driving display screens for our In-Venue product of which I am the product owner. And very exciting it is too, because the real world is the new frontier (this pdf is also a good primer). If you see what I mean, but more on that another time.

So.. I had to overclock the Pi to improve browser performance to even get near to acceptable speed and smoothness of animations. Pro Tip, the Pi is not a graphics device! Having done this and got acceptable results for a clunky prototype to demo with, and load averages that stayed on the sane side of normal I thought I'd better see if I was frying the CPU. And because I will inevitably forget this useful command I'm saving it here for posterity. Here's how I got the temperature reading..

/opt/vc/bin/vcgencmd measure_temp

I'm writing a technical document using google docs, and I want to put code snippets into it.
I thought this would be hard, before I discovered http://hilite.me/

This awesome, and awesomely simple, web app converts snippets of code into coloured HTML.
It can format a comprehensive range of languages and apply an equally impressive variety of styles.

Here's a snip of javascript, I just copied and pasted it straight in here, so it doesn't handle the overflow well, but you have to admit that its pretty cool for something that has a quick copy/paste/click/copy/paste workflow:

for (var i = 0; i < dataObj.eventData.children.length; i++) {
  if (dataObj.isProduction){
   dataObj.eventData.children[2].outcome.coupling = "1";
  }
  if (dataObj.eventData.children[i].outcome.coupling.length > 0) { 
    outcomeData = dataObj.eventData.children[i].outcome;
    priceBoost[counter] = Object.create(priceBoostObject);
    priceBoost[counter].createPriceBoostHTML(outcomeData);
    priceBoost[counter].applyPriceBoost(outcomeData);
    priceBoost[counter].applyExtraCss(outcomeData);
    priceBoost[counter].initialiseAnimatedImages('animated-' + outcomeData.id, 'images/test.png', 'test.html');
    priceBoost[counter].checkTextWidth(outcomeData.id);
    counter++;
  }
}

I tried to install a couple of updates on my work laptop, running Ubuntu 12.04, a minute or two ago when prompted by the update manager, and I got the "requires installation of untrusted packages" error. I've since dicovered that there are two ways round this, one is to allow untrusted packages by doing the update as root or via sudo, and saying "y" when asked

Install these packages without verification [y/N]?

sudo apt-get clean
cd /var/lib/apt
sudo mv lists lists.old
sudo mkdir -p lists/partial
sudo apt-get clean 
sudo apt-get update

I spent a while figuring out how to get a list of email recipient addresses from the maillog, without duplicates, for a specific day on RHEL. In the end I distilled it into to one line.

I'm sure I will have to do it again, so I'm making a note of it here, meantime if you need to extract recipient addresses from maillog you're welcome to try it. just paste it onto the command line and hit the go button, its surpisingly quick.

cat /var/log/maillog | grep "Oct 19" |\
grep to= |cut -f5 -d":" | cut -f2 -d"=" | cut -f1 -d"," | \
sed 's/<//' | sed 's/>//' | \
sort | uniq > addresses.txt

Update The original article mentioned in this post is no longer available, but if you are still interested in query profiling in MySQL, check out this http://dev.mysql.com/doc/refman/5.0/en/show-profiles.html
I will write up an quick start guide to profiling myself here, one day.
 
-- original post
this article is a great way to get started using the mysql query profiler.

If you've never used it before take some time to check it out, it will change the way you think about the database forever.

Use these two commands to get the top ten and top ten repeaters from MySQL's slow query log.

mysqldumpslow -t 10 ./slow-log > /home/danny/top_ten_slow_query.txt

mysqldumpslow -a -s c -t 10 ./slow-log > /home/danny/top_ten_repeat_slow_query.txt

Yes, yet another one that I always have to look up, I think it must be my age!

find /path/to/files* -mtime +5 -exec rm {} \;

I've often wondered, idly, how to get MySQL to output a row number column, which would rank sorted and grouped results.
Well thanks to this excellent post I've found out how:

SELECT *, @rownum:=@rownum+1 as rank FROM ( 
-- Your Query Goes in Here
        SELECT t.*
        FROM table t
        WHERE something
        group by 2,3,4
        order by 1 desc limit 20
    ) day_rank, (SELECT @rownum:=0) r;

Want to install apc on CENTOS or RHEL?
REad this: http://www.agileapproach.com/blog-entry/howto-install-pecl-apc-cache-centos-without-xampp

I thought I'd put this in as well, since I had to google for it, using -n will make iostat provide you with stats for nfs shares too.

iostat -nh 5

nfsstat -cvn -o nfs

This is a useful one if, like us, you find that the account used to create the procedure doesn't have the privileges required to execute it, or perhaps you've revoked the original definers grant. (DoH!)

ALTER PROCEDURE procedure_name SQL SECURITY DEFINER;javascript:void(0)

I like to use nano to edit the crontab, but I don't want to change the default editor.
(Some people are very un-funny about that kind of thing!)

This is the one-liner to use nano, and I seldom remember it.

env EDITOR=nano crontab -e

Another piece of DBA hoodoo that I seldom need!

SELECT @@global.read_only;
SET GLOBAL read_only=1;
SELECT @@global.read_only;

Another one that I have to google every time.
Not being a DBA I don't do this very often, but now and again I find myself in the Hot Seat.

SET GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
START SLAVE;
SHOW SLAVE STATUS;

I do this so infrequently that I always have to google it.
Now I can search my own blog!
openssl pkcs12 -in mycert.pfx -out certificate.cer -nodes