Dorian's Developer Cheat Sheet
Configure terminal features
Add directories to cd search path
Using Zsh, it's easy to make it so the cd command searches a group of directories. Add to the ~/.zshrc config file:
setopt auto_cd
cdpath=($HOME $HOME/code $HOME/projects)
Set terminal colors
Best option: Use Zsh and Oh My Zsh
Zsh is a great Unix terminal, and Oh My Zsh makes it look pretty!
Customize your terminal manually
Linux Terminal Customization Guide for Beginners
# In the ~/.bashrc file, add a line:
PS1="\[\033[35m\]\u\[\033[39m\]@\[\033[95m\]\H \[\033[36m\]\W\[\033[39m\]$ "
Set ls colors
How to Change the Colors of Directories and Files in the ls Command
echo $LS_COLORS
LS_COLORS="rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:"
Setting up SSH
Create SSH key
# Best encryption to use
ssh-keygen -t ed25519 -C "username@host.com"
# or RSA
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
How to Configure SSH Key-Based Authentication on a Linux Server
Copy key from host to server
# Linux/Unix
ssh-copy-id -i ~/.ssh/KEYNAME.pub USER@HOST
# Windows
type $env:USERPROFILE\.ssh\SSH-KEY-FILE.pub | ssh IP-ADDRESS-OR-FQDN "cat >> .ssh/authorized_keys"
Additional references:
Windows 10 OpenSSH Equivalend of ssh-copy-id | Christopher Hart
How to set up an SSH config-file for beginners | GitHub
Set SSH config
First, create a file ~/.ssh/config:
touch ~/.ssh/config
# Open with your preferred editor.
nano ~/.ssh/config
Add your remote hosts to your config file.
# ~/.ssh/config
Host remote1
User username
Hostname sub.domain.com
Host remote2
User username
Hostname sub2.domain.com
IdentityFile ~/.ssh/id_rsa # optional: path to SSH private key
LocalForward 9000 localhost:9000 # optional: port forwarding
ForwardX11 yes # optional: UI forwarding, if configured
If I would normally type
ssh user@sub.domain.com
I can just type
ssh remote1
Git
Configuring git tab completion
Tab completion for git should work by default in Linux/Unix. For Windows, see my post on Stack Overflow.
Setting git command aliases
git config --global alias.lg "log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr)%C(bold blue)<%an>%Creset' --abbrev-commit"
git config --global alias.co checkout
git config --global alias.sw switch
git config --global alias.ci commit
git config --global alias.st status
git config --global alias.br branch
git config --global alias.fix '!git add . && git ci --amend -n --no-edit && git push -f'
git_aliases | andreevWork on GitHub
Git remotes
# See all remotes:
git remote -v
# Add another remote:
git remote add <remote-name> <url>
# e.g.
git remote add diff-repo https://github.com/username/reponame
# Push to other remote
git push diff-repo master
# Change URI for remote repository
git remote set-url origin new.git.url/here
github - Pushing to a different git repo | Stack Overflow
Rebase a branch on top of changes merged to origin/main
This sequence of commands is useful when you want to update your working branch to have changes merged in main. Depending on the changes in the working branch and main, it is likely there will be conflicts when running the rebase command.
git fetch origin main
git rebase origin/main
git push -f origin HEAD
Set default pull behavior to rebase
git config --global pull.rebase true
Git cherry-pick
git cherry-pick {COMMIT-SHA}
# e.g. cherry picking commit 'f' from branch Feature into Main
# Initially:
# a - b - c - d Main
# \
# e - f - g Feature
git checkout main
git cherry-pick f
# Now:
# a - b - c - d - f Main
# \
# e - f - g Feature
Git reset changes on one file
Sometimes changes need to be reset on just one file to a previous commit in the git history. To do this, use the -- argument for the git command that switches to file names, as shown here.
git checkout COMMITSHA -- fileToReset.md
Git Cherry Pick | Atlassian Git Tutorial
Windows PowerShell grep equivalent
The Powershell equivalent of the linux grep command is Select-String. It doesn't work identical to grep, so it's best to learn the command directly from the docs and not to alias grep.
Using Out-String -Stream ensures that the pipe output is interpreted correctly by the Select-String program.
ls | Out-String -Stream | Select-String "some phrase"
# Use Regex
ls | Out-String -Stream | Select-String -Pattern "$r*g[a-z]x"
# Search a file
Select-String -Path myfile.txt -Pattern "words to find"
Vim Cheat Sheet
It's important to be familiar with at least one common command-line text editor, whether it be Vim, Nano, or Emacs.
Need help choosing which editor is best for you? Consider this.
My personal favorite is Vim because it's almost always installed by default and very powerful. It's complicated, though, so it's always good to have the Vim Cheat Sheet bookmarked for reference.
Softlinks
Unix
ln -s {source-filename} {symbolic-filename}
# Remove a link just like you'd remove a file:
rm {symbolic-filename}
How to: Linux / UNIX create soft link with ln command
Windows
New-Item -Path C:\LinkDir -ItemType SymbolicLink -Value F:\RealDir
# Command Prompt
mklink [[/d] | [/h] | [/j]] <link> <target>
Creating hard and soft links using PowerShell | Stack Overflow
Running a program disconnected from a session
Screen
Screen is a Linux terminal program that continues to run even after disconnecting. You can have multiple windows and go between them.
For example, if running a long Jupyter notebook, run it within screen and it will continue to run, even if your terminal session ends.
# One way: Screen -> tty emulator
^A C # create window
^A N # next window
^A D # disconnect from screen
screen -R # reconnect to screen
Tmux
Cheat Sheet A beginner's guide to tmux | Red Had
tmux detach-client -P -s session-name-or-id
Adding GCC Versions for C++ compilation
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install gcc-11 g++-11
Set alternatives
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 100 --slave /usr/bin/g++ g++ /usr/bin/g++-10 --slave /usr/bin/gcov gcov /usr/bin/gcov-10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 90 --slave /usr/bin/g++ g++ /usr/bin/g++-9 --slave /usr/bin/gcov gcov /usr/bin/gcov-9
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 80 --slave /usr/bin/g++ g++ /usr/bin/g++-8 --slave /usr/bin/gcov gcov /usr/bin/gcov-8
Then, we run:
sudo update-alternatives --config gcc
We can select the version we want with:
Output
There are 3 choices for the alternative gcc (providing /usr/bin/gcc).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/gcc-10 100 auto mode
1 /usr/bin/gcc-10 100 manual mode
2 /usr/bin/gcc-8 80 manual mode
3 /usr/bin/gcc-9 90 manual mode
Press <enter> to keep the current choice[*], or type selection number:
See directory storage size
du -sh PATH_TO_DIR
Fast high compression
### This requires 7z and tar
# Create a tar archive:
7z a ARCHIVE.tar PATH_TO_DIRECTORY
# Compress the archive using xz: (-mmt4 specifies using 4 processors)
7z a -mmt4 ARCHIVE.tar.xz ARCHIVE.tar
# Extract
tar -xvf ARCHIVE.tar.xz
# or
7z e ARCHIVE.tar.xz
7z e ARCHIVE.tar
Python
Anaconda
Consider using Mamba, a fast, robust, and cross-platform Anaconda alternative. For Mamba, replace
condawithmambain almost any conda command.
# Create conda environment
conda create -n myenv python=3.9
# Create conda environment from file
conda env create -f environment.yml
# List environments:
conda env list
# Switch environments:
conda activate {ENVIRONMENT_NAME}
# See installed packages
conda list
conda list -n myenv
# install packages with pip
conda install -n myenv pip
conda activate myenv
pip <pip_subcommand>
# Add local packages
# (local packages must have `setup.py` file)
conda activate myenv
conda install pip
pip install ./path/to/packagedirectory
# Save environment.yml file
conda env export > environment.yml
For instructions on how to create an environment.yml file, see the Anaconda docs.
Running Jupyter
# This runs whatever jupyter notebook in the directory its run on
jupyter notebook --no-browser --port=#####
# Jupyter Lab version:
jupyter-lab
# Connect to the remote on that port to see the notebook:
ssh -L localhost:PORT:localhost:PORT REMOTE_MACHINE_NAME
Convert between char and int
>>> chr(97)
'a'
>>> ord('a')
97
How can I convert a character to a integer in Python, and viceversa? | Stack Overflow