Add base configuration

- Follow XDG standard: ~/.config and ~/.local folders
- Set environment variables and define aliases within ~/.config/shell
- Add installation script for easy setup and maintenance
  (i.e., `install-dotfiles` and `update-dotfiles`,
   and a `ensure-locales` helper)
- Add README.md with info on the installation and general notes

.bashrc

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+# `bash`-specific configurations
+
+
+# Prevent running this file twice, as a non-login `bash` enters here,
+# sources ~/.profile, and ~/.profile sources this file again
+[ -n "$BASHRC_LOADED" ] && return
+BASHRC_LOADED=1
+
+
+# Load configuration files common to all kinds of shells,
+# if not already done by a `bash` login shell
+[ -z "$PROFILE_LOADED" ] && [ -f "$HOME/.profile" ] && . "$HOME/.profile"

.config/shell/README.md

@@ -0,0 +1,11 @@
+# Shell-related Configurations
+
+This folder contains files that are sourced by `bash` and `zsh`.
+
+They are not executable.
+The `#!/bin/sh` line documents the dialect for readers and editors;
+    it has no effect, since the files are sourced and never run directly.
+
+[`welcome`](./welcome) and [`logout`](./logout)
+    depend on helper functions defined in [`~/.profile`](../../.profile),
+    so they cannot work standalone.

.config/shell/aliases

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+# Aliases used in all kinds of shells
+
+
+# Manage the bare `git` repository in ~/ holding the dotfiles
+alias dotfiles='git --git-dir=$DOTFILES_DIR --work-tree=$HOME'
+
+
+alias grep='grep --exclude-dir=.git'

.config/shell/env

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+# Environment variables for all kinds of shells
+
+
+# Standard XDG base directories
+# See: https://wiki.archlinux.org/title/XDG_Base_Directory
+
+export XDG_CACHE_HOME="$HOME/.cache"
+export XDG_CONFIG_HOME="$HOME/.config"
+export XDG_DATA_HOME="$HOME/.local/share"  # also set in ~/.local/bin/dotfiles-{install,update}
+export XDG_STATE_HOME="$HOME/.local/state"
+
+# Make up a XDG directory for binaries (that does not exist in the standard)
+export XDG_BIN_HOME="$HOME/.local/bin"
+
+
+# Convenient names for various places in the system
+
+export DOTFILES_DIR="$XDG_DATA_HOME/dotfiles"  # also set in ~/.local/bin/dotfiles-{install,update}
+
+
+# Generic shell configs
+
+
+[ -t 0 ] && export GPG_TTY=$(tty)
+
+
+export PAGER=less
+export LESS="--chop-long-lines --ignore-case --LONG-PROMPT --no-init --raw-control-chars --status-column --quit-if-one-screen"
+
+
+[ -f "$XDG_CONFIG_HOME/shell/locale" ] && . "$XDG_CONFIG_HOME/shell/locale"
+
+
+# Move common tools' config and cache files into XDG directories
+
+export LESSHISTFILE="$XDG_STATE_HOME/less/history"

.config/shell/locale

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Locale settings for headless machines
+
+
+# Drop what a client may forward over `ssh`,
+# because `AcceptEnv LANG LC_*` may be set in /etc/ssh/sshd_config
+unset \
+    LC_ALL \
+    LC_ADDRESS \
+    LC_COLLATE \
+    LC_CTYPE LC_IDENTIFICATION \
+    LC_MEASUREMENT \
+    LC_MESSAGES \
+    LC_MONETARY \
+    LC_NAME \
+    LC_NUMERIC \
+    LC_PAPER \
+    LC_TELEPHONE \
+    LC_TIME
+
+
+# Set every LC_* category implicitly with the `$LANG` fallback
+export LANG=C.UTF-8

.local/bin/README.md

@@ -0,0 +1,3 @@
+# User-local Executables
+
+This folder contains executable files that are on the `$PATH`.

.local/bin/dotfiles-install

@@ -0,0 +1,115 @@
+#!/bin/sh
+
+# Installation script to make the dotfiles available in ~/
+#
+# `git` is the only dependency for this script to run (See: https://git-scm.com)
+#
+# See: https://code.webartifex.de/alexander/dotfiles#installation
+
+
+set -eu
+
+
+XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"  # also set in ~/.config/shell/env
+XDG_STATE_HOME="${XDG_STATE_HOME:-$HOME/.local/state}"  # also set in ~/.config/shell/env
+
+DOTFILES_BRANCH="main"
+DOTFILES_DIR="$XDG_DATA_HOME/dotfiles"  # also set in ~/.config/shell/env
+DOTFILES_HTTPS="https://code.webartifex.de/alexander/dotfiles"
+DOTFILES_SSH="git@git.webartifex.de:alexander/dotfiles.git"
+
+BACKUPS_DIR="$XDG_STATE_HOME/dotfiles-backups"
+BACKUP_DIR="$BACKUPS_DIR/$(date +%Y%m%d-%H%M%S)"
+
+
+if [ -d "$DOTFILES_DIR" ]; then
+
+    [ "${1:-}" = "--force" ] && force=1 || force=0
+
+    if [ "$force" -ne 1 ]; then
+
+        echo ""
+        echo "The dotfiles are already installed at: $DOTFILES_DIR"
+        echo ""
+        echo "Options:"
+        echo "  - Run the installation again with '--force'"
+        echo "  - Update with 'dotfiles pull' and continue using them"
+        echo ""
+
+        exit 0
+
+    fi
+
+    echo "Backing up the existing repository to: $BACKUP_DIR"
+    mkdir -p "$BACKUP_DIR"
+    mv "$DOTFILES_DIR" "$BACKUP_DIR/dotfiles"
+
+fi
+
+
+git clone --bare "$DOTFILES_HTTPS" "$DOTFILES_DIR"
+
+
+_git() {
+    git --git-dir="$DOTFILES_DIR" --work-tree="$HOME" "$@"
+}
+
+
+if ! _git show-ref --verify --quiet "refs/heads/$DOTFILES_BRANCH"; then
+
+    echo "" >&2
+    echo "Internal error: branch '$DOTFILES_BRANCH' missing in the repository" >&2
+    echo "" >&2
+    echo "Available branches:" >&2
+    _git branch --format='  %(refname:short)' >&2
+    echo "" >&2
+
+    exit 1
+
+fi
+
+
+_git config remote.origin.fetch '+refs/heads/*:refs/remotes/origin/*'
+_git fetch origin
+
+
+# Do not checkout project documentation intended for web GUIs
+_git config core.sparseCheckout true
+{
+    echo "/*"
+    echo "!/LICENSE.txt"
+    echo "!/README.md"
+} > "$DOTFILES_DIR/info/sparse-checkout"
+
+
+# Back up files in the user's $HOME folder if a checkout is about to overwrite them
+_conflicts=$(_git ls-tree -r --name-only "$DOTFILES_BRANCH" | while IFS= read -r f; do
+    if [ -e "$HOME/$f" ] || [ -L "$HOME/$f" ]; then echo "$f"; fi
+done)
+
+if [ -n "$_conflicts" ]; then
+
+    echo "Backing up pre-existing files to: $BACKUP_DIR"
+    echo "$_conflicts" | while IFS= read -r f; do
+        mkdir -p "$BACKUP_DIR/$(dirname "$f")"
+        cp -a "$HOME/$f" "$BACKUP_DIR/$f"
+    done
+
+fi
+
+# Put the dotfiles in the user's $HOME folder
+_git checkout --force "$DOTFILES_BRANCH"
+
+# Do not show files not tracked in the dotfiles repository because there are simply too many
+_git config --local status.showUntrackedFiles no
+
+# Prefer `ssh` for syncing between the machines
+_git remote set-url origin "$DOTFILES_SSH"
+
+
+echo ""
+echo "The dotfiles were installed successfully (branch: $DOTFILES_BRANCH)"
+echo ""
+echo "Reload your shell to use them:"
+echo "    exec \$SHELL -l"
+echo ""

.local/bin/dotfiles-update

@@ -0,0 +1,87 @@
+#!/bin/sh
+
+# Replace the local `dotfiles` repository with a fresh install
+# by downloading and re-running the latest `dotfiles-install`
+#
+# Refuses to run if there are uncommitted or unpushed changes,
+# unless called with `--force`
+
+set -eu
+
+
+XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"  # also set in ~/.config/shell/env
+DOTFILES_DIR="$XDG_DATA_HOME/dotfiles"  # also set in ~/.config/shell/env
+
+
+if [ -d "$DOTFILES_DIR" ]; then
+
+    _git() {
+        git --git-dir="$DOTFILES_DIR" --work-tree="$HOME" "$@"
+    }
+
+    # Keep the machine on its current branch (e.g., "desktop")
+    branch=$(_git symbolic-ref --short HEAD) || {
+        echo "" >&2
+        echo "Detached HEAD => re-run after 'dotfiles checkout <branch>'" >&2
+        echo "" >&2
+
+        exit 1
+    }
+
+    [ "${1:-}" = "--force" ] && force=1 || force=0
+
+    if [ "$force" -ne 1 ]; then
+
+        if [ -n "$(_git status --porcelain)" ]; then
+            echo "" >&2
+            echo "There are uncommitted changes!" >&2
+            echo "" >&2
+            _git --no-pager diff HEAD --stat >&2
+            echo "" >&2
+            echo "=> Commit and push them, or re-run with --force" >&2
+            echo "" >&2
+
+            exit 1
+        fi
+
+        if _git rev-parse --verify --quiet "origin/$branch" >/dev/null \
+            && [ -n "$(_git log --oneline "origin/$branch..$branch")" ]; then
+            echo "" >&2
+            echo "There are unpushed commits!" >&2
+            echo "" >&2
+            _git --no-pager log --oneline "origin/$branch..$branch" >&2
+            echo "" >&2
+            echo "=> Push them, or re-run with --force" >&2
+            echo "" >&2
+
+            exit 1
+        fi
+
+    fi
+
+else
+    branch="main"
+fi
+
+
+installer_url="https://code.webartifex.de/alexander/dotfiles/raw/branch/$branch/.local/bin/dotfiles-install"
+
+installer_path=$(mktemp)
+trap 'rm -f "$installer_path"' EXIT
+
+
+if command -v curl >/dev/null 2>&1; then
+    curl -fsSL "$installer_url" -o "$installer_path"
+elif command -v wget >/dev/null 2>&1; then
+    wget -q "$installer_url" -O "$installer_path"
+else
+    echo "" >&2
+    echo "Neither curl nor wget are installed!" >&2
+    echo "=> Install one of them" >&2
+    echo "" >&2
+
+    exit 1
+fi
+
+
+sh "$installer_path" --force

.profile

@@ -0,0 +1,54 @@
+#!/bin/sh
+
+# Main setup file executed for all kinds of shells
+
+
+# Prevent loading ~/.profile twice in `bash`
+export PROFILE_LOADED=1
+
+
+# Basic utilities
+
+_command_exists() {
+    command -v "$1" 1>/dev/null 2>&1
+}
+
+_in_bash() {
+    [ -n "$BASH_VERSION" ]
+}
+
+_in_zsh() {
+    [ -n "$ZSH_VERSION" ]
+}
+
+_prepend_to_path () {
+    if [ -d "$1" ] ; then
+        case :$PATH: in
+            *:$1:*) ;;
+            *) PATH=$1:$PATH ;;
+        esac
+    fi
+}
+
+
+_prepend_to_path "$HOME/.local/bin"
+
+
+[ -f "$HOME/.config/shell/env" ] && . "$HOME/.config/shell/env"
+
+
+[ -f "$HOME/.config/shell/aliases" ] && . "$HOME/.config/shell/aliases"
+
+
+# Source ~/.profile_local, which holds machine-specific ENV variables
+[ -f "$HOME/.profile_local" ] && . "$HOME/.profile_local"
+
+
+# Load `bash`-specific configurations for non-login `bash` shells
+if [ -n "$BASH_VERSION" ] && [ -f "$HOME/.bashrc" ]; then
+    . "$HOME/.bashrc"
+fi
+
+
+# Ensure ~/.profile is loaded each time `bash` starts
+unset PROFILE_LOADED

.zshrc

@@ -0,0 +1,7 @@
+#!/bin/zsh
+
+# `zsh`-specific configurations
+
+
+# Load configuration files common to all kinds of shells
+[ -f "$HOME/.profile" ] && . "$HOME/.profile"

README.md

@@ -0,0 +1,61 @@
+# Dotfiles
+
+This repository contains useful (config) files.
+
+There are two branches:
+- [*main*](https://code.webartifex.de/alexander/dotfiles/src/branch/main) (~ "headless")
+- [*desktop*](https://code.webartifex.de/alexander/dotfiles/src/branch/desktop) (for GNOME 48+ on X11)
+
+`main` contains dotfiles intended to be used on all kinds of machines
+    and can be thought of as a "minimal" or "server" version.
+It targets [Debian](https://www.debian.org/) 13
+    but is kept working on older versions and other distributions as well.
+`desktop` is (re-)based on top of `main`
+    and adds configurations for
+    [GNOME](https://www.gnome.org/) 48+
+    on [X11](https://www.x.org/)
+    and many applications,
+    be it end-user software or common development utilities.
+
+
+## Installation
+
+Simply run:
+
+```sh
+curl https://code.webartifex.de/alexander/dotfiles/raw/branch/main/.local/bin/dotfiles-install > dotfiles-install && sh ./dotfiles-install && rm ./dotfiles-install
+```
+
+or
+
+```sh
+wget https://code.webartifex.de/alexander/dotfiles/raw/branch/main/.local/bin/dotfiles-install -O dotfiles-install && sh ./dotfiles-install && rm ./dotfiles-install
+```
+
+This downloads a simple [installation script](.local/bin/dotfiles-install)
+    and then executes it.
+The script's only dependency is [`git`](https://git-scm.com/).
+So, it should not be too hard to get this going.
+
+The repository is cloned as a bare repository into `~/.local/share/dotfiles`
+    and its files are checked out into `~/` directly.
+Pre-existing files are backed up to `~/.local/state/dotfiles-backups` beforehand.
+Afterwards, the files can be managed with the
+    [`dotfiles`](.config/shell/aliases#L7) alias,
+    for example, `dotfiles status` or `dotfiles pull`.
+
+The above commands install the *main* variant.
+To install the *desktop* variant,
+    switch to the [desktop](https://code.webartifex.de/alexander/dotfiles/src/branch/desktop) branch first.
+
+Normally, I advise against executing shell scripts from the internet,
+    but this one is short enough to be read even by beginners.
+So, convince yourself that it is not harmful!
+
+
+## Shells
+
+The config files in this repository are optimized for usage with
+    [GNU's Bourne again shell](https://man7.org/linux/man-pages/man1/bash.1.html),
+    or `bash` for short,
+    and the popular [zsh](https://www.zsh.org/).