My Learning

It include the following but not limited to

• Linux basic
• Linux advanced
• vim
• Markdown
• //TODO
• Shell scripting
• C/C++
• CUDA
• Git/GitHub
• Web hosting

Linux Basic

A few shortcuts

• ctrl + alt + T - Open terminal
• ctrl + alt + <up/right/left> - Switch workspace
• ctrl + alt + shift + <right/left> - Move current window to right/left workspace
• ctrl + alt + <F1/F2/F3/F4/F5/F6> - Open TTY login (does not use GUI)
• ctrl + alt + <F7> - Leave TTY screen and switch to GUI
• <up/down> - Move back/forth the previously typed terminal commands

Basic commands

$ pwd       # path of working directory
$ ls        # list the contents of current directory
$ cd Music  # changes the current directory to `Music` directory
$ cd ..     # change the directory to one level up except at '/'
$ cd -      # jumps to previous `pwd` before a `cd`
$ ls -l     # long listing the file
$ ls -lrt   # list file based on the modified date. recent at the last.
$ man ls    # list manual pages for  `ls`
$ ls --version # shows the version of `ls`. Sometimes it is `<cmd> -v`

• pwd - path of working directory
• ls - list the contents of current working directory i.e pwd
• cd folder - changes the current directory to folder
• cd .. - change the directory to one level up except at '/'
• cd - - jumps to previous pwd before a cd
• ls -l - long listing of file/folder
• ls -lrt - list file based on the modified date. recent at the last
• man <cmd> - list manual pages for any valid linux cmd
• <cmd> --version - shows the version of valid cmd

vim

Three modes - command - insert - visual

switch modes

• ESC : to cmd mode
• i,a : to insert mode
• C-v, V: to visial mode

Arrows

• Sometimes arrow keys may not work
• hjkl
• ldur=left-down-up-right

insert

• i - insert before cursor
• a - insert after cursor

• A - insert at end of line

• wq = write and quit

• q = quit

• q! = quit without saving

Edit in cmd mode

• d - cut or del
• y - yank or copy
• x - del a char
• dd -del a line
• d - deletes select
  yy - copy line
  p - paste yanked line after cursor line
  u - undo
  C-r - redo

  Visual

  C-v - rectangle selection V - line select ggVG - select all

  Navigation

  C-] - function decalartion C-o - prev cursor position

  Linux Administration

  The easiest of all Linux distribution is Ubuntu. I have been using Linux along side from 2009, and from 2016 Linux is my main stream operating system. I have used Debian, Ubuntu, Fedora, OpenSUSE, and a few others. Thanks to my under-graduate projects and {TCE's FStival 2008](). But, now Linux Mint Cinnamon is my favourite (from 2017). I begin to dislike Unity-Gnome in Ubuntu, so moved to Mint. Am I ranting or self-trumpeting? Both. Okay, it is 2020. But still some commands are still in my muscle memory. I am just logging it here.

  Admin commands

  • echo $HOME - Displays the home of user who run it

  • ls -a - Also list the hidden folders/files (it beging with a .) e.g .bashrc in $HOME

  • df -h - List all mounted partition along with used/available/% size

  • top - List all running process based on % of CPU usage. press q to close

  • du -h . - List the file/folder size of current directory

  • lscpu - List the processor details

  • lsusb - List of devices attached to the USB port

  • cat /proc/meminfo - List the RAM/memory details

  • dmesg | grep tty - Find the tty/devName just attached via USB

  • less /var/log/auth.log- All login/out/suspend session are recored

  • /var/log/* - has all the logs file e.g. apt-get log is in `/var/log/apt/history.log

  • ps -ef | grep firefox- List processes/id with the name firefox

  • kill <pid> - Kill the process with sending sigterminate

  • kill -9 <pid> - Kill the process with sending sigkill

  • /home/<user>/.bashrc - User specific bashrc file

  • source .bashrc- Run and set bachrc file in current session

  • /home/<user>/.bash_history - List of cmd typed by the user

  • echo $PATH - Displays the environment variable PATH

  • PATH=$PATH:/usr/local/cuda-10.0/bin - Set path in shell

  • export PATH - will pass this env variable for subsequent commands eric

  • ssh username@ip-address # e.g ssh rajesh@10.6.3.112

  • scp localfile user@ip-address:/some/location/on/server

  Installation

  • Most of new machine. You may have to disable fastboot/safeboot in BIOS
  • Download you favourite linux as iso file
  • Burn iso to formatted USB/DVD using rufus, UNetbootin , usb-creator or Startup Disk creator
  • Reboot and press the key F12/F10 (differ based on manufacturer) to bootfrom USB/DVD
  • Mostly positive answer for moast. At select drive location, use MANUALLY
  • Give appropriate drives "/", /home, and swap (/boot, /tmp optinal)
  • You may leave it with / alone also.
  • Upon installation and reboot. Grub will appear.

  Markdown Syntax

  Heading

  # Heading 1
  ## Heading 2 ##
  and so on till H6.
  
  A short form for H1 and H2 is
  Heading 1
  =========
  Heading 2
  ----------
  

  Quoting text

  Syntax	Output

  Source code

  This is inline `code` and
  e.g. Use `git log` to see the commits.
  

  • This is inline code and
  • e.g Use git log to see the commits.

  ---

  This is called code block or fenced code. You may specify the language.

  
    #include <iostream>
    int main(int argc, char* argv[]){
      std::cout << "Hello There!"<< std::endl;
      return EXIT_SUCCESS;
    }
  

  

  You may mention language from this list to enable syntax hightlighting at line 1.

  Hyperlinks/Attachments

  This is [Google](www.google.com) as a link.
  

  This is Google as a link.

  ---

  ![Alt text rajzdocs logo](images/logo-6e5006f2.png)
  ![Some logo](http://example.com/logo.png)
  

  

  Text formatting

  *This text will be italic* and _This will also be italic_
  
  **This text will be bold** and __This will also be bold__
  
  _We **can** combine both_
  
  ~~This text will be stricked-out~~
  

  This text will be italic and This will also be italic

  This text will be bold and This will also be bold

  We can combine both

  This text will be stricked-out

  List

  * one // Unordered
  * two
  * three
  
  1. One // Ordered
  2. Two
  3. Three
  
  - This is also
  - Unordered
  - An another way
  

  Multi-level or nesting

  - Can be nested
    * One.One
    * One.Two
  - Can also be nested this way
    1. Two.One
    1. Two.Two. What?
    1. You see this? auto-increment.
  - Three
    - Thread.One
  

  • one // Unordered
  • two
  • three
  1. One // Ordered
  2. Two
  3. Three
  • This is also
  • Unordered
  • An another way

  Multi-level or nesting

  • Can be nested
    • One.One
    • One.Two
  • Can also be nested this way
    1. Two.One
    2. Two.Two. What?
    3. You see this? auto-increment.
  • Three
    • Thread.One

  Horizontal rule

  If you need horizontal rule then, use three
  asterisks,
  
  ***
  
  hyphens or underscores like the below.
  
  ---
  
  Also, have a blank line before and after!
  
  ___
  

  If you need horizontal rule then, use three asterisks,

  ---

  hyphens or underscores like the below.

  ---

  Also, have a blank line before and after!

  ---

  Table

  Header 1 | Header 2
  -------- | -----------
  cell 1x1 | cell 1x2
  cell 2x1 | cell 2x2
  
  

  Header 1	Header 2
  cell 1x1	cell 1x2
  cell 2x1	cell 2x2

  you may use handy table generator website to generate large tables.

  References

  • From the author of Markdown
  • Github Markdown Guide
  • Markdownguide Cheat-sheet
  • Markdownguide DOs and DONTs

  Not part of markdown

  This search engine [1] is lot better than [2] and [3]
  
  [1] - www.google.com
  [2] - www.yahoo.com
  [3] - www.bing.com
  

  This search engine [1] is lot better than [2] and [3] Here's a sentence with a footnote. [^4].

  [1] - www.google.com [2] - www.yahoo.com [3] - www.bing.com [^4]: This is the footnote.