🛠 Configuring Shell Profiles

Shell profiles allow you to customize your interactive session — define aliases, set environment variables, and load helper functions automatically.

🗃 File Types Overview

Different shells look for different startup files depending on whether they’re login shells or interactive non-login shells.

Common Files

File	Used By	When Loaded
.profile	sh, bash (login)	Login shells
.bash_profile	bash	Login shells
.bashrc	bash (non-login)	Interactive non-login shells
.zshrc	zsh	Always loaded
.zprofile	zsh (login)	Login shells

Note: On macOS since Catalina, zsh is default; older versions used bash.

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🔁 Loading Order Example (Bash)

1. Login shell loads:
2. /etc/profile

3. First found among: ~/.bash_profile, ~/.bash_login, ~/.profile

4. Non-login interactive shell loads:

5. ~/.bashrc

So many developers put this in their ~/.bash_profile:

if [ -f ~/.bashrc ]; then
    source ~/.bashrc
fi

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🧰 Practical Customizations

Aliases

Add shortcuts for frequently used commands:

alias ll='ls -la'
alias gs='git status'
alias dc='docker-compose'

Environment Variables

Set global settings:

export EDITOR=vim
export HISTSIZE=10000
export PS1='\u@\h:\w\$ '

Functions

Define reusable logic:

mkcd() {
    mkdir -p "$1" && cd "$1"
}

Path Extensions

Add custom directories to $PATH:

export PATH="$HOME/bin:$PATH"

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🧼 Keeping Things Organized

As your config grows, split it into logical parts:

~/.config/shell/
├── aliases.sh
├── env.sh
├── functions.sh
└── prompt.sh

Then source them from your main profile:

for file in ~/.config/shell/*.sh; do
    source "$file"
done

👉 Continue to: Cross-Platform Testing Setup