.bashrc

#!/bin/bash

idempotentAdd() {
    # Extend given PATH-type variable in an idempotent way.
    # $1 = Either the string "append" or the string "prepend".
    # $2 = Name of the PATH-type variable.
    # $3 ... $N = Directories to be added.

    # If we don't have all the arguments we need or mode is unrecognized, return:
    if [[ ${#} -le 2 ]] || ! [[ ${1} == "append" || ${1} == "prepend" ]]; then
        return -1
    fi

    # If the given PATH-type variable is empty, we will create it:
    if [[ -z ${!2} ]]; then
        # Concatenate all arguments with colons, write to the output variable:
        printf -v ${2} ":%s" ${@:3}
        # Remove the spurious first colon.
        printf -v ${2} "%s" ${!2:1}
        return -1
    fi

    if [[ ${1} == "append" ]]; then
        for VAR in ${@:3}; do
            idempotentAddSingle ${1} ${2} ${VAR}
        done
    else
        for ((ind=$#; ind>=3; ind--)); do
            idempotentAddSingle ${1} ${2} ${!ind}
        done
    fi
}

idempotentAddSingle() {
    # If the given PATH-type variable already contains the to-be-added directory,
    # return. This check makes the function idempotent.
    if [[ :${!2}: == *":${3}:"* ]]; then
        return
    fi
    # Append, or prepend, to the given PATH-type variable.
    case ${1} in
        "prepend") printf -v ${2} "%s" "${3}:${!2}" ;;
        *)         printf -v ${2} "%s" "${!2}:${3}" ;;
    esac
}

# Make commonly-used tools globally accessible:
idempotentAdd "append" "PATH" "${HOME}/scripts"

# Add Rust package executables to PATH:
if [[ -d ${HOME}/.cargo/bin ]]; then
    idempotentAdd "append" "PATH" "${HOME}/.cargo/bin"
fi

# Perform MacOS-specific actions:
if [[ ${OSTYPE} == "darwin"* ]]; then
    # We don't want Homebrew talking to Google Analytics.
    export HOMEBREW_NO_ANALYTICS=1
    # Add Homebrew executables to PATH:
    idempotentAdd "prepend" "PATH" "/opt/homebrew/bin"
    idempotentAdd "prepend" "PATH" "/opt/homebrew/sbin"
    # Add Go package executables to PATH:
    if [ -d /opt/homebrew/opt/go ]; then
        export GOPATH="${HOME}/golang"
        export GOROOT="/opt/homebrew/opt/go/libexec"
        idempotentAdd "append" "PATH" "${GOROOT}/bin"
        idempotentAdd "append" "PATH" "${GOPATH}/bin"
    fi
    # Add LLVM executables to PATH:
    if [ -d /opt/homebrew/opt/llvm ]; then
        idempotentAdd "append" "PATH" "/opt/homebrew/opt/llvm/bin"
    fi
    # # Enable iTerm2 back-end for Matplotlib.
    # export MPLBACKEND="module://itermplot"
    # # Reverse Matplotlib colors to accomodate my terminal's dark background.
    # export ITERMPLOT=rv
fi

# Use the "lsd" utility, if available, instead of the default one:
if type lsd > /dev/null 2>&1; then
    alias ls=lsd
# Otherwise, use the color option of "ls":
elif [[ ${OSTYPE} == "linux-gnu" ]]; then
    alias ls="ls --color=always"
elif [[ ${OSTYPE} == "darwin"* ]]; then
    alias ls="ls -G"
fi

# Use the color option of "grep" and "less":
# alias grep="grep --color=always"
# alias less="less -R"

# Make sure tmux uses the correct colors. Also, in order to avoid breaking
# chroots, urge tmux to create its socket under ${HOME}.
alias tmux="mkdir -p ${HOME}/tmp; tmux -2 -S ${HOME}/tmp/default"

# If we are in an interactive session, tie up/down arrow keys to command history.
if [[ $- =~ i ]]; then
    bind '"\e[A": history-search-backward'
    bind '"\e[B": history-search-forward'
    bind '"\e0A": history-search-backward'
    bind '"\e0B": history-search-forward'
fi

# Make sure we use VIM as the default editor.
export VISUAL=vim
export EDITOR=vim

# Various Java tools require this to be set up to work.
if [ -f "/usr/libexec/java_home" ]; then
    export JAVA_HOME=$(/usr/libexec/java_home)
fi

# Load xmake profile:
if [ -s ~/.xmake/profile ]; then
    source ~/.xmake/profile
fi

# Use FZF if it exists:
if [ -f ~/.fzf.bash ]; then
    source ~/.fzf.bash
fi

# Activate my Python environment:
source ~/pyenv/bin/activate