update.sh

#!/bin/bash

DIFF_ONLY=0

if [ "$1" = "-d" ]; then
    DIFF_ONLY=1
    echo "Diff only..."
    shift
fi

# Get all the files that we're going to write.
# This is the union of all the paths in both 'common' and the specified host dirs.
for dir in common $*; do
    ([ -d "$dir" ] && find $dir -type f)
done | sort | uniq | grep -v '[.]prepend$' | while read file; do
    # 'base' is the top-level dir (e.g. 'home', 'etc').
    base=`echo "$file" | cut -d/ -f2`
    # 'file' is the path (e.g. '.i3/config', 'X11/xorg.conf.d/20-foo.conf').
    file=`echo "$file" | cut -d/ -f3-`

    # Optional prefix for running commands (e.g. 'sudo', or 'echo' for debugging).
    prefix=""
    dest=""

    # Things going in /etc need sudo.
    if [ $base = "etc" ]; then
        prefix="sudo "
        dest="/etc"
    fi

    # 'home' is $HOME
    if [ $base = "home" ]; then
        dest=$HOME
    fi

    # Don't allow directories other than /etc and $HOME.
    if [ -z "$dest" ]; then
       echo "Not sure where to write $base"
       exit 1
    fi

    # Enable for debugging.
    #prefix="echo $prefix"

    # Create the temporary output file.
    echo -n > /tmp/dotfile

    # Prepend any '.prepend' files.
    for part in common $*; do
       [ -e "$part/$base/$file.prepend" ] && cat "$part/$base/$file.prepend" >> /tmp/dotfile
    done

    # Then the main content.
    for part in common $*; do
       [ -e "$part/$base/$file" ] && cat "$part/$base/$file" >> /tmp/dotfile
    done

    # Append any '.append' files.
    for part in common $*; do
       [ -e "$part/$base/$file.append" ] && cat "$part/$base/$file.append" >> /tmp/dotfile
    done

    if diff "/tmp/dotfile" "$dest/$file" > /dev/null; then
        #if [ $DIFF_ONLY -eq 0 ]; then
            echo -e "$dest/$file \033[01;92m[skip]\033[0m"
        #fi
    else
        if [ $DIFF_ONLY -eq 1 ]; then
            echo -e "$dest/$file \033[01;91m[diff]\033[0m"
            diff "/tmp/dotfile" "$dest/$file"
            echo
            for part in common $*; do
                [ -e "$part/$base/$file" ] && echo "  cp \"$dest/$file\" \"$part/$base/$file\""
            done
            echo
        else
            echo -e "$dest/$file \033[01;91m[update]\033[0m"
            $prefix mkdir -p `dirname $dest/$file`
            $prefix bash -c "cat /tmp/dotfile > '$dest/$file'"
        fi
    fi

    if [ $DIFF_ONLY -eq 0 ]; then
        # Anything in bin/ gets +x.
        if [[ "$file" =~ ^bin/ ]]; then
            chmod +x "$dest/$file"
        fi
    fi
done

# if [ $DIFF_ONLY -eq 0 ]; then
#     # Compile .emacs --> .emacs.elc
#     update_script=$PWD/update-emacs.el
#     (cd ~; emacs -nw -q --script $update_script)

#     # Update gnome settings
#     dconf load / < ~/.config/gnome-settings
# fi