Category Archives: Ubuntu Linux

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Links on Site

Due to the purchase of Github from Microsoft, I have removed my account and all repositories.  This will also affect a few posts I have made here.  The links used to embed some small snippets (aka GISTs) of code will no longer work.  As time is available I will start fixing them manually.  Until then I thank you for your patience.

 

Thanks,
Matthew Curry

How to use a PS1 in Linux/MAC

Here are the PS1‘s I use for my daily driver.  Feel free to take them and change them up.

I use different colors, so one doesn’t accidentally login or run something as root (which is in red, users are yellow).

To use these, simply copy and paste them into either the root user; or regular user’s .bashrc.

Alternatively you can add them to /etc/profile to make them enforced system wide. 

For MAC, it is the same; however the PS1 is a little different. See below.

 

Root

 

User

Using Nano with Markdown in Linux

Fan of nano?  Like having pretty colors to see where you messed up? Of course we do!  Much like many of us, I use nano.  Its quick, easy, and readily available.  However, I like to see the highlighting of my language.  As many of you know, there are “nanorc” files, that will tell nano how to handle language highlight.

They are usually located in  /usr/share/nano/ (at least in ubuntu); and you can make your own under your home directory with a .nanorc file.  I can post about that later…

For now let get markdown working in nano!

You will need to create a file called markdown.nanorc by doing the following:

 sudo touch /usr/share/nano/markdown.nanorc

Now that the file is created, we just need to populate it with the following below text:

(Alternatively, you can run the following to do it for you.)

sudo wget -O /usr/share/nano/markdown.nanorc goo.gl/AZthpr

who did what with ROOT?! [Updated]

When you are not sure who is using SUDO on a server, and you really need to know who keeps making that annoying change.  You can install something to watch them, and maintain that software and related logs. Keep it setup in your package management system, and make sure it doesn’t have any patches.

OR

You could use the little-known (at least those I have asked in the field) modifications I will list below.  They are two fold.  One, you will enable to record who logs in and uses SUDO, and records their session. Much like many pieces of software out there today.  The one catch to my method is simple.  You already have the software installed, yup this has been a feature of SUDO since version 1.7.4p4.  So nothing else to install, worry about, or maintain.  It is also very easy to setup, see below:


/etc/sudoers modifcation:
All you need to do is to add 2 tags to all required sudoers entries.
*(where "su" specified, either with command or alias). 
LOG_INPUT and LOG_OUTPUT
Example: 
%admins ALL=(ALL) NOPASSWD: LOG_INPUT: LOG_OUTPUT: ALL

It will add the following default log dir structure to sudoers: Defaults iolog_dir=/var/log/sudo-io/%{user}
Note:
Output is logged to the directory specified by the iolog_dir option (/var/log/sudo-io by default) using a unique session ID that is included in the normal sudo log line, prefixed with TSID=.  The iolog_file option may be used to control the format of the session ID.  Output logs may be viewed with the
sudoreplay(8) utility, which can also be used to list or search the available logs.   Keeping in mind that if the user has a really long session you will be viewing it like a movie, it will replay as if he is sitting there typing.  With this in mind, sudoreplay gives you the ability to play back at faster speeds.  This makes it easier to find where things happened in a long recording.

So that is one good method to help find a culprit, but what if you are just looking at history of root?  Can you tell me who ran what? Can you tell me when they ran the commands you see when you type ‘history’?  By default, no.  The next tidbit of info is very useful, and extremely easy to add to your machines.  Simply add the following to your /etc/profile:

export HISTTIMEFORMAT="%m.%d.%y %T "

Yes, that is a space at the end.  If you do not put that in there you will end up with it running together with the actual command typed in history.  So your history should look like the example below:

1995 06.10.15 13:08:05 top
1996 06.10.15 13:08:05 clear
1997 06.10.15 13:08:05 df -h
1998 06.10.15 13:08:05 umount /media
1999 06.10.15 13:08:05 sudo umount /media
2000 06.10.15 13:08:05 sudo su –
2001 06.10.15 13:08:07 history

I hope this helps someone save some time, as it has me.  Please feel free to share with others.

-M

 

Kill Switch Pictures/Update

Hello All,

For those following along, I have moved Kill Switch, my sons e-vehicle project. To a permanent page.  I have also added a gallery for the work as I go.  Keep an eye…

You can also subscribe to my RSS if you like.

Thanks,
-M


P.S.

Thanks to TJUMP7 for the donated 4gb SD card, and help with the motor controllers!  I can’t wait to get all the parts and get it going!

Handy One-Liners – Full Debian Update

This one is great for a “Full Update” on debian / ubuntu machines.

It calls the script without ever installing anything (assuming curl is installed).  Be sure to run as root, either with sudo or as root directly.

As you can see in the snippet; it uses a script that is remotely hosted (in a github gist).  This is great because you  can see exactly what it does by looking at the script.  It just calls system commands, so it can’t do anything malicious.  Just run sudo, then the above command and it will run the below script:

Another trick you can do with something like this, is copy it to  /usr/bin/fullupdate (as root of course), and ensure its executable “sudo chmod +x /usr/bin/fullupdate”.  Then you can call “sudo fullupdate”, from anywhere and use it when needed. Alternatively, you can use it on a cron to run on a schedule!  If you don’t want all the options, just download the script and change it for your liking.

 

Welcome to open source.

Got an Idea? Need Help? Raspberry PI prototyping!

Just another thing that I helping with lately.  If anyone need help with a new idea for a Raspberry PI, or IoT device message me.  I have been  through several POC’s (proof of concepts).

Keep in mind, if you are working on a new product; or sensitive information I keep all client info secret, and have no issues with an NDA.

  • Home Automation
  • Voice Recognition
  • Several TTS/STT Options
  • Custom Hardware
    • Integration with existing hardware
  • Custom Software
    • Custom Plugins/Adjustments
    • Coding
  • R&D on Subject Matter
    • Build
    • Test
    • Design
  • … and whatever else is needed …

Happy to just answer questions; or see what I can do to help.  Just contact me.

Setting up Raspberry PI 3 Wifi (Via CLI/BASH)

To all Raspberry PI Tinkerers…
I have had several people as for a how-to on setting up wifi on a Raspberry PI via command line.  It is actually quite easy.

Here is a quick tutorial I hope helps.


First, we need to open the file that controls what wifi we connect to.

sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

This will open the file that controls what access points your RPI looks for.

Here is an example of how one should look (RPI3):

country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
        ssid="SSID_HERE"
        psk="KEY_HERE"
        key_mgmt=WPA-PSK
}

Now that this file has been updated; we will need to reboot to ensure everything comes back up correctly.
Ensure that your RPI is connected to wifi.

Simply type: ifconfig

Then it will show all the interfaces, the wireless is usually “WLAN0”, or something that starts with a “W”.
The ethernet will usually start with an “E”, for example “ETH0” is very common.

Don’t forget! Linux Learning Resources

This is kept under the Linux Learning Project and Learning Resources section of the site, and is updated occasionally with new links.  Feel free to suggest one by contacting me directly.


LEARNING RESOURCES

Help/Chat:

Resources:

Need DevOps Help?

  • Had issues with your DevOps pipeline?
  • Need help streamlining automation or configuration management?
  • Need to green field or “lift and shift” applications into the cloud?

If you are trying to do any of these, and running into issues please contact me.  I am now open to consulting directly.  Fixing even a few small inefficiencies can have a huge impact on the bottom line.  Not only that, if the DevOps philosophies are really taken up, its likely that the employee base will also be happier, and proud of their accomplishments as a team.

As far as technologies I support, please take a look at my Technologies page.  (Updated often)  I am also happy to take on new ones for a project if needed.

Creating an efficient pipeline is what I do; and a fully functional system that is working well can be an amazing thing.

 

Matthew Curry
MattCurry.Com