link_dot_files.sh

#!/bin/sh -e

safeLn() {
    srcFile=$1
    target=$2
    linkTarget=$2
    [ -e "$srcFile" ]
    if [ -d "$target" ]; then
        target="$target/$(basename "$srcFile")"
    fi
    if [ ! -e "$target" ] || diff -q "$srcFile" "$target"; then
        ln -sf "$srcFile" "$linkTarget"
    else
        diff -u "$srcFile" "$target" || true
        echo "Override  and link $target to $srcFile ? Y/n"
        read -r ans
        if [ "$ans" = Y ] || [ "$ans" = y ]; then
            [ -d "$target" ] && rm -r "$target"
            ln -sf "$srcFile" "$linkTarget"
        fi
    fi
}

SYSTEM_CONFIG_DIR=${SYSTEM_CONFIG_DIR:-~/SystemConfig}
if [ -z "$1" ]; then
    cd "$SYSTEM_CONFIG_DIR/Config"
else
    cd "$SYSTEM_CONFIG_DIR/$1"*
fi
for dotFile in .*; do
    if [ "$dotFile" = "." ] || [ "$dotFile" = ".." ]; then
        continue
    elif [ -d "$dotFile" ]; then
        mkdir -p "$HOME/$dotFile"
        for config in "$dotFile"/*; do
            [ -e "$config" ] && safeLn "$PWD/$config" "$HOME/$dotFile/"
        done
    else
        safeLn "$PWD/$dotFile" "$HOME/$dotFile"
    fi
done