update_home.sh

#!/usr/bin/env bash
## Update root dir from all the dot files in this directory. Back up existing
## versions of replaced files by tacking on a .update.
##
## TODO Ensure that this is run from the correct directory
## TODO Move If symlink exist in $HOME and it should be in $XDG_CONFIG_HOME move
##      it to $XDG_CONFIG_HOME
##
## 2016-01-15 omit .svn .sync .git .DS_Store
## 2021-01-25 Copy .profile_`hostname` or .profile_$USER files
## 2025-02-02 If XDG_CONFIG_HOME is set, put select files in tha config directory
type _include.sh &>/dev/null && . _include.sh

ext='.update' ## Name used for suffixing backed up names.

#shopt -s dotglob
## Iterate over all "dot" files and directores
for i in .*; do
	case "$i" in
	## Skip some dot-files
	. | .. | .svn | .git | .sync | .DS_Store | .profile.* | .*.bak | .*_history) continue ;;

	## Copy to XDG_CONFIG_HOME (or HOME) destination
	.profile_$(uname -s) | .profile_${USER:-$(id -un)} | .profile_${HOSTNAME%.local} |
	.alias | .bash_completion.d )
		[ -n "$XDG_CONFIG_HOME" -a ! -d "$XDG_CONFIG_HOME" ] && mkdir -p "$XDG_CONFIG_HOME"
		[ -n "$XDG_CONFIG_HOME" ] && target="$XDG_CONFIG_HOME" || target="$HOME"
		;;

	## Skip other profiles that do not apply to this environment
	.profile_*) continue ;;

	## Default: .profile, .bashrc, .bash_profile, .inputrc, .vimrc, .vim, .emacs, .emacs.d, .ssh, .gnupg, .gitconfig, .gitignore, .gitattributes, .config, .local, .cache, .state, etc.
	*)
		target="$HOME"
		;;
	esac

	## Check that it's a file and is up to date
	if [ -s "$i" ]; then
		if [ -f ${target}/"$i" ]; then
			## If home version is not a hardlink to this one, back it up
			if [ ! "$i" -ef ${target}/"$i" ]; then
				## Even if files are not the same, only backup if their contents
				## are different.
				if diff -q "$i" ${target}/"$i" 2>/dev/null; then
					rm ${target}/"$i"
				elif [ "$(uname -s)" = Darwin ] && which osx_trash >/dev/null; then
					osx_trash ${target}/"$i"
				elif [ -e ${target}/"$i$ext" ]; then
					echo "   \"${t_red}${target}/$i$ext${t_reset}\" already exists... cannot back up."
				else
					echo "   Backing up \"${target}/$i\" to \"${target}/$i${ext}\"" && mv ${target}/"$i" ${target}/"$i${ext}"
				fi
				echo "   ${t_green}Linking \"$i\"${t_red}"
				ln -s "$(pwd)/$i" ~
				echo -n "$t_reset"
			fi
			# elif [ -L ${target}/"$i" ]; then
			# 	## It's a link, so probably nothing to update
			#   if [ ! "$i" -ef  ${target}/"$i" ]; then
			# 		if [ "$`uname -s`" = Darwin ] && which osx_trash >/dev/null; then
			# 			osx_trash ${target}/"$i"
			# 		elif [ -e ${target}/"$i$ext" ]; then
			# 			echo "   \"$t_red${target}/$i$ext$t_reset\" already exists... cannot back up."
			# 	  else
			# 			echo "   Backing up \"${target}/$i\" to \"${target}/$i$ext\"" && mv ${target}/"$i" ${target}/"$i$ext"
			# 	  fi
			# 		echo "   Linking \"$i\""
			# 		ln -s "`pwd`/$i" ~
			# 	fi
		elif [ -e ${target}/"$i" ]; then
			echo "   ${t_red}${target}/$i exists, but it not a file (it should be a file)${t_reset}".
		else ## Create link
			echo "   ${t_green}Linking \"${target}/$i\"${t_red}"
			# ln "`pwd`/$i" ~ || ln -s "`pwd`/$i" ~
			ln -s "$(pwd)/$i" ~
			echo -n "$t_reset"
		fi
	else ## Assume source is directory; check that it is up to date
		if [ -e ${target}/"$i" -o -L ${target}/"$i" -a ! "$(readlink ${target}/"$i")" -ef "$i" ]; then
			if [ ! "$i" -ef ${target}/"$i" ]; then
				[ ! -e ${target}/"$i${ext}" ] && echo "   Backing up directory \"${target}/$i\" to \"${target}/$i${ext}\"" && mv ${target}/"$i" ${target}/"$i${ext}"
				echo "   ${t_green}Linking \"${target}/$i\" directory${t_red}"
				ln -s "$(pwd)/$i" ~
				echo -n "$t_reset"
			fi
		else
			echo "   ${t_green}Linking \"${target}/$i\" directory${t_red}"
			ln -s "$(pwd)/$i" ~
			echo -n "$t_reset"
		fi
	fi
done