Move Rustup and Cargo config file under XDG Base Directory

Refs.
- https://rust-lang.github.io/rustup/environment-variables.html
- https://doc.rust-lang.org/cargo/reference/environment-variables.html

See also:
- https://wiki.archlinux.org/title/XDG_Base_Directory#Partial
- rust-lang/rustup#247
- rust-lang/cargo#1734
- rust-lang/rfcs#1615
- rust-lang/cargo#5183
- rust-lang/cargo#148

.bash/variables.sh

@@ -37,8 +37,16 @@ export LESSOPEN="| $HOMEBREW_PREFIX/bin/src-hilite-lesspipe.sh %s"
 export LC_ALL=en_US.UTF-8
 export LANG=en_US.UTF-8
 
+export STARSHIP_CONFIG="$XDG_CONFIG_HOME/starship/config.toml"
+export STARSHIP_CACHE="$XDG_CACHE_HOME/starship"
+export INPUTRC="$XDG_CONFIG_HOME/readline/inputrc"
+export RBENV_ROOT="$XDG_DATA_HOME/rbenv"
+export IRBRC="$XDG_CONFIG_HOME/irb/irbrc"
+export RUSTUP_HOME="$XDG_DATA_HOME/rustup"
+export CARGO_HOME="$XDG_DATA_HOME/cargo"
+
 export PYENV_ROOT="$HOME/.pyenv"
-export PATH="$HOMEBREW_PREFIX/opt/libxml2/bin:$HOMEBREW_PREFIX/opt/libxslt/bin:$HOMEBREW_PREFIX/opt/libiconv/bin:$HOMEBREW_PREFIX/opt/openssl/bin:$HOMEBREW_PREFIX/opt/libressl/bin:$HOMEBREW_PREFIX/opt/curl/bin:$HOMEBREW_PREFIX/opt/sqlite/bin:$HOMEBREW_PREFIX/opt/nss/bin:$HOMEBREW_PREFIX/opt/ruby/bin:$HOMEBREW_PREFIX/opt/go/bin:$HOMEBREW_PREFIX/opt/python/bin:$HOMEBREW_PREFIX/opt/python/libexec/bin:$HOMEBREW_PREFIX/opt/openjdk/bin:$HOMEBREW_PREFIX/opt/coreutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/bin:$HOMEBREW_PREFIX/opt/findutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-indent/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-sed/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-tar/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-which/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-getopt/bin:$HOMEBREW_PREFIX/opt/grep/libexec/gnubin:$HOMEBREW_PREFIX/opt/m4/bin:$HOMEBREW_PREFIX/opt/make/libexec/gnubin:$HOMEBREW_PREFIX/opt/file-formula/bin:$HOMEBREW_PREFIX/opt/apr/bin:$HOMEBREW_PREFIX/opt/unzip/bin:$HOMEBREW_PREFIX/opt/ssh-copy-id/bin:$HOMEBREW_PREFIX/opt/util-linux/bin:$HOMEBREW_PREFIX/opt/util-linux/sbin:$HOMEBREW_PREFIX/opt/postgresql@16/bin:$HOME/bin:$HOME/.cargo/bin:$PYENV_ROOT/bin:$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin"
+export PATH="$HOMEBREW_PREFIX/opt/libxml2/bin:$HOMEBREW_PREFIX/opt/libxslt/bin:$HOMEBREW_PREFIX/opt/libiconv/bin:$HOMEBREW_PREFIX/opt/openssl/bin:$HOMEBREW_PREFIX/opt/libressl/bin:$HOMEBREW_PREFIX/opt/curl/bin:$HOMEBREW_PREFIX/opt/sqlite/bin:$HOMEBREW_PREFIX/opt/nss/bin:$HOMEBREW_PREFIX/opt/ruby/bin:$HOMEBREW_PREFIX/opt/go/bin:$HOMEBREW_PREFIX/opt/python/bin:$HOMEBREW_PREFIX/opt/python/libexec/bin:$HOMEBREW_PREFIX/opt/openjdk/bin:$HOMEBREW_PREFIX/opt/coreutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/bin:$HOMEBREW_PREFIX/opt/findutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-indent/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-sed/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-tar/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-which/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-getopt/bin:$HOMEBREW_PREFIX/opt/grep/libexec/gnubin:$HOMEBREW_PREFIX/opt/m4/bin:$HOMEBREW_PREFIX/opt/make/libexec/gnubin:$HOMEBREW_PREFIX/opt/file-formula/bin:$HOMEBREW_PREFIX/opt/apr/bin:$HOMEBREW_PREFIX/opt/unzip/bin:$HOMEBREW_PREFIX/opt/ssh-copy-id/bin:$HOMEBREW_PREFIX/opt/util-linux/bin:$HOMEBREW_PREFIX/opt/util-linux/sbin:$HOMEBREW_PREFIX/opt/postgresql@16/bin:$HOME/bin:$CARGO_HOME/bin:$PYENV_ROOT/bin:$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin"
 if [ -n "$(echo $CPU_BRAND | grep -o 'Apple')" -a "$(uname -m)" = "arm64" ]; then
   export PATH="$PATH:/usr/local/bin"
 fi
@@ -73,10 +81,4 @@ export GUILE_TLS_CERTIFICATE_DIRECTORY="$HOMEBREW_PREFIX/etc/gnutls/"
 
 export RUBY_CONFIGURE_OPTS="--with-openssl-dir=$HOMEBREW_PREFIX/opt/[email protected]"
 
-export STARSHIP_CONFIG="$XDG_CONFIG_HOME/starship/config.toml"
-export STARSHIP_CACHE="$XDG_CACHE_HOME/starship"
-export INPUTRC="$XDG_CONFIG_HOME/readline/inputrc"
-export RBENV_ROOT="$XDG_DATA_HOME/rbenv"
-export IRBRC="$XDG_CONFIG_HOME/irb/irbrc"
-
 export GPG_TTY=$(tty)

.zsh/variables.zsh

@@ -40,8 +40,16 @@ export LESSOPEN="| $HOMEBREW_PREFIX/bin/src-hilite-lesspipe.sh %s"
 export LC_ALL=en_US.UTF-8
 export LANG=en_US.UTF-8
 
+export STARSHIP_CONFIG="$XDG_CONFIG_HOME/starship/config.toml"
+export STARSHIP_CACHE="$XDG_CACHE_HOME/starship"
+export INPUTRC="$XDG_CONFIG_HOME/readline/inputrc"
+export RBENV_ROOT="$XDG_DATA_HOME/rbenv"
+export IRBRC="$XDG_CONFIG_HOME/irb/irbrc"
+export RUSTUP_HOME="$XDG_DATA_HOME/rustup"
+export CARGO_HOME="$XDG_DATA_HOME/cargo"
+
 export PYENV_ROOT="$HOME/.pyenv"
-export PATH="$HOMEBREW_PREFIX/opt/libxml2/bin:$HOMEBREW_PREFIX/opt/libxslt/bin:$HOMEBREW_PREFIX/opt/libiconv/bin:$HOMEBREW_PREFIX/opt/openssl/bin:$HOMEBREW_PREFIX/opt/libressl/bin:$HOMEBREW_PREFIX/opt/curl/bin:$HOMEBREW_PREFIX/opt/sqlite/bin:$HOMEBREW_PREFIX/opt/nss/bin:$HOMEBREW_PREFIX/opt/ruby/bin:$HOMEBREW_PREFIX/opt/go/bin:$HOMEBREW_PREFIX/opt/python/bin:$HOMEBREW_PREFIX/opt/python/libexec/bin:$HOMEBREW_PREFIX/opt/openjdk/bin:$HOMEBREW_PREFIX/opt/coreutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/bin:$HOMEBREW_PREFIX/opt/findutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-indent/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-sed/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-tar/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-which/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-getopt/bin:$HOMEBREW_PREFIX/opt/grep/libexec/gnubin:$HOMEBREW_PREFIX/opt/m4/bin:$HOMEBREW_PREFIX/opt/make/libexec/gnubin:$HOMEBREW_PREFIX/opt/file-formula/bin:$HOMEBREW_PREFIX/opt/apr/bin:$HOMEBREW_PREFIX/opt/unzip/bin:$HOMEBREW_PREFIX/opt/ssh-copy-id/bin:$HOMEBREW_PREFIX/opt/util-linux/bin:$HOMEBREW_PREFIX/opt/util-linux/sbin:$HOMEBREW_PREFIX/opt/postgresql@16/bin:$HOME/bin:$HOME/.docker/bin:$HOME/.cargo/bin:$PYENV_ROOT/bin:$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin"
+export PATH="$HOMEBREW_PREFIX/opt/libxml2/bin:$HOMEBREW_PREFIX/opt/libxslt/bin:$HOMEBREW_PREFIX/opt/libiconv/bin:$HOMEBREW_PREFIX/opt/openssl/bin:$HOMEBREW_PREFIX/opt/libressl/bin:$HOMEBREW_PREFIX/opt/curl/bin:$HOMEBREW_PREFIX/opt/sqlite/bin:$HOMEBREW_PREFIX/opt/nss/bin:$HOMEBREW_PREFIX/opt/ruby/bin:$HOMEBREW_PREFIX/opt/go/bin:$HOMEBREW_PREFIX/opt/python/bin:$HOMEBREW_PREFIX/opt/python/libexec/bin:$HOMEBREW_PREFIX/opt/openjdk/bin:$HOMEBREW_PREFIX/opt/coreutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/libexec/gnubin:$HOMEBREW_PREFIX/opt/ed/bin:$HOMEBREW_PREFIX/opt/findutils/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-indent/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-sed/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-tar/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-which/libexec/gnubin:$HOMEBREW_PREFIX/opt/gnu-getopt/bin:$HOMEBREW_PREFIX/opt/grep/libexec/gnubin:$HOMEBREW_PREFIX/opt/m4/bin:$HOMEBREW_PREFIX/opt/make/libexec/gnubin:$HOMEBREW_PREFIX/opt/file-formula/bin:$HOMEBREW_PREFIX/opt/apr/bin:$HOMEBREW_PREFIX/opt/unzip/bin:$HOMEBREW_PREFIX/opt/ssh-copy-id/bin:$HOMEBREW_PREFIX/opt/util-linux/bin:$HOMEBREW_PREFIX/opt/util-linux/sbin:$HOMEBREW_PREFIX/opt/postgresql@16/bin:$HOME/bin:$HOME/.docker/bin:$CARGO_HOME/bin:$PYENV_ROOT/bin:$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin"
 if [ -n "$(echo $CPU_BRAND | grep -o 'Apple')" -a "$(uname -m)" = "arm64" ]; then
   export PATH="$PATH:/usr/local/bin"
 fi
@@ -81,10 +89,4 @@ export RUBY_CONFIGURE_OPTS="--with-openssl-dir=$HOMEBREW_PREFIX/opt/[email protected]"
 
 export ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE="fg=#F2E6D4,bg=#7E87D6,bold,underline"
 
-export STARSHIP_CONFIG="$XDG_CONFIG_HOME/starship/config.toml"
-export STARSHIP_CACHE="$XDG_CACHE_HOME/starship"
-export INPUTRC="$XDG_CONFIG_HOME/readline/inputrc"
-export RBENV_ROOT="$XDG_DATA_HOME/rbenv"
-export IRBRC="$XDG_CONFIG_HOME/irb/irbrc"
-
 export GPG_TTY=$(tty)

bin/setup_rust.sh

@@ -1,8 +1,11 @@
 #!/bin/bash
 set -eu
 
+: "${XDG_DATA_HOME:=$HOME/.local/share}"
+: "${CARGO_HOME:=$XDG_DATA_HOME/cargo}"
+
 # if [[ ! -d "$HOME/.cargo/bin" ]]; then RUSTUP_INIT_SKIP_PATH_CHECK=yes rustup-init -y --no-modify-path --default-host x86_64-apple-darwin --default-toolchain stable --profile default; fi
-if [[ ! -d "$HOME/.cargo/bin" ]]; then RUSTUP_INIT_SKIP_PATH_CHECK=yes rustup-init -y --no-update-default-toolchain --no-modify-path; fi
+if [[ ! -d "$CARGO_HOME/bin" ]]; then RUSTUP_INIT_SKIP_PATH_CHECK=yes rustup-init -y --no-update-default-toolchain --no-modify-path; fi
 rustup update
 
 if [ "$(uname -m)" = "x86_64" ]; then