GNU-Linux#

command line: A text-based interface for a user to interact with an operating system.
shell : The program that accepts user input and returns their output
terminal : A windowed application that displays the input and output of command line commands.

Software Selections and Motivations#

OS : Ubuntu : Stability Audio : pavucontrol : Ubiquity Shell : zsh : plugins, popularity Terminal : TODO trying alacritty Text editor/IDE : neovim : vim style hotkeys and philosophy Neovim package manager: TODO trying vim-plug

Common commands, symbols, and special variables#

whatis : Display a one line description of a command
man : View the manual of a command
echo : display a line of text
cd : Change directory

  • cd : navigate to previous directory

touch : change file timestamps (though is used to create empty files)
ls : List directory contents

ls -l shows file permissions ls -al shows hidden files | cp : Copy files and directories | rm : Remove files or directories * [rm -R] remove a directory and it’s contents recursively | mv : Move a file to a different directory | cat : concatenate files and print on the standard output | ~ : refers to the HOME directory | eval : Evaluates and executes strings as a shell command | $_ : special variable that refers to the last argument of the previous command | source : execute commands from a file in the current shell environment | curl : makes an http request * [curl -s https://example.com/data/example.csv > data/example_data.csv] makes the request silently and suppresses progress output and error messages | zip : package and compress a files | unzip : list, test, or extract compressed files in a ZIP archive | chsh : change login shell chmod : change file mode bits chmod +x <filename> gives execute permissions chmod 700 <directory/filename> set permission for .ssh directory useradd : low level command that requires some flags to setup a fully functional user adduser :minteractive higher level tool that will prompt information like password, phone number etc. mserdel : remove a user userdel -r <username> : removes user and their home directory usermod: modify a user account usermod -aG sudo <username> : adds a user to the sudo group sed: stream editor for filtering and transforming test sed -i “s/<oldstring>/<newstring>/” <file> sed -i ‘$ a This is appended to the last line’ file.txt su : change user su <username> passwd : change user password passwd -d <username> : delete a user’s password scp scp myfile.txt user@192.168.1.10:/home/user/ sudo: Execute a command as another user sudo -u <username> : run command as username user chown: Change file ownership chown <USER>:<GROUP> <FILE>

Man Pages#

TODO

Linux Directory Structure#

TODO

Scripts#

TODO

Aliases#

TODO

Environmental variables#

TODO

How to install a .deb file on ubuntu#

NOTE: Software installed from .deb files will only be able to update if you enable an associated repository, by default they do not update when <apt get upgrade> is run

sudo dpkg -i filename.deb

If the previous command fails, then run the following command to resolve missing dependencies

sudo apt-get install -f

Chaining shell commands#

&& : Performs the following command only if the previous command succeeds || : Performs the following command only if the previous command fails

Pipes connect the stout of the previous command to the stin of the following command.

Example: cat file.txt | grep “error” && echo “Errors found!” : prints “Errors found!” if file.txt contains lines that contain the word “error”

Makefiles#

The make command will execute a makefile (typically named “Makefile”). Makefiles are a convenient way to automate repetitive tasks such as software compilation. A makefile consists of targets, dependencies, and commands.

Target : The file or action you want to create or run (Ex: myprogram) Dependencies: Files that are needed to create the target (Such as source code files) Command : the command to execute to create the target (Ex: gcc -o myprogram main.c)

How to handle zipped files#

TODO