opensourceworks.org

I have used eval in the past in perl, bash and javascript.  Sure there are valid cases to use it, i guess, but mostly don’t.

Great article here.

So here’s another cool python lego project me and my son have been working on.

Be sure to check these videos, because this is where it started for us:

Work in progress.

More on this soon..

1. 1. Need a way to download the install cd from Apple’s store
      I got an xcloud for a month – could have used macincloud
   2. download High Sierra from the app store on the mac
   3. Create virtualbox image
      I Had to go for generic Mac OSX 64 bit, not the specific High Sierra one !!

VBoxManage modifyvm Sierra  --cpuidset 00000001 000306a9 00020800 80000201 178bfbff
VBoxManage setextradata "Sierra" "VBoxInternal/Devices/efi/0/Config/DmiSystemProduct" "iMac11,3"
VBoxManage setextradata "Sierra" "VBoxInternal/Devices/efi/0/Config/DmiSystemVersion" "1.0"
VBoxManage setextradata "Sierra" "VBoxInternal/Devices/efi/0/Config/DmiBoardProduct" "Iloveapple"
VBoxManage setextradata "Sierra" "VBoxInternal/Devices/smc/0/Config/DeviceKey" "ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
VBoxManage setextradata "Sierra" "VBoxInternal/Devices/smc/0/Config/GetKeyFromRealSMC" 1
VBoxManage setextradata "Sierra" "VBoxInternal2/EfiGraphicsResolution" "1920x1080"

1. Configure
2. change resolution
   

   Method 1: VBoxManage setextradata “Type Your VM Name Here” VBoxInternal2/EfiGraphicsResolution HxV  (Recommended)
   -------------------------------------------------------------------------------------------------------------------
   
   Method 2: VBoxManage setextradata “Type Your VM Name Here” VBoxInternal2/EfiHorizontalResolution H  (Alternative)
   	  VBoxManage setextradata “Type Your VM Name Here” VBoxInternal2/EfiVerticalResolution V
   -------------------------------------------------------------------------------------------------------------------
   Resolutions to choose:
     1280x720 | 1920x1080 | 2560x1440 | 2048x1080 | 3840x2160 | 5120x2880 | 1280x800 | 1280x1024 |1600x900 | 1440x900
        HD 	FHD	    QHD          2K	     4K	         5K
   -------------------------------------------------------------------------------------------------------------------

    

Again, I had a large list of hostnames which I needed resolved to their ip addresses.

• nslookup: slow
• ping -c 1: slow
• getent hosts: “random” ipv6 addresses
• no fping available

So I still use perl for gethostbyname() or getaddrinfo():

Example below takes input from stdin/pipe.

perl -MSocket -nwle'my @addresses = gethostbyname($_); my @ips = map { inet_ntoa($_) } @addresses[4 .. $#addresses]; print "@ips"'

Let’s say you want to change the value of a header value based on the source location, ie localhost vs external.  Or you can drop it all together. This is how it’s done in nginx.

We’re setting a variable first using map in the http{} block and then use it later in the location{} section.

• Add this to the http{} section:   if loopback, it will set the $customkey variable to the original header value of ‘custom-key’, else it will default to empty

map $remote_addr $customkey {
     127.0.0.1 $http_custom_key ;
     default "";
}

• Add this to the location{} section where you want the use this for your proxy_pass:  (re)set the header to the previously set variable or remove it.

proxy_set_header custom-key  $customkey;

Installing ubuntu from the live-cd these days is too easy, really: insert usb stick, boot, install. Done.

The ability to try before installing is just the icing on the cake.  You check if all your hardware is supported (especially network, display, mouse/keyboard) and go…

If you installed it next to the preinstalled Windows and the latest update destroyed your GRUB bootloader config (or any other), use the same live-cd/usb stick to recover.

https://help.ubuntu.com/community/Boot-Repair

just run these lines in a terminal and let the repairing begin:

sudo add-apt-repository ppa:yannubuntu/boot-repair 
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair