Add dotfiles install and backup script

.local/bin/dotfiles-install.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# this script will install the dotfiles from the target git repository, and back up any conflicting files
+# credit for this idea and basic script outline goes to https://www.atlassian.com/git/tutorials/dotfiles
+
+DOTFILES_REPO_DIR="$HOME/git/dotfiles"
+DOTFILES_REPO_URL="https://git.blakenorth.net/dotfiles"
+DOTFILES_BACKUP_DIR="$HOME/.dotfiles-backup" # cannot contain the character '#'
+
+set -e
+
+# check for the git command and exit if it doesn't exist
+if ! command -v git > /dev/null;then
+   echo 'git is not installed or could not be found in $PATH, please install git to proceed'
+   exit 1
+fi
+
+git clone --bare "$DOTFILES_REPO_URL" "$DOTFILES_REPO_DIR"
+
+dot() {
+   git --git-dir="$DOTFILES_REPO_DIR" --work-tree="$HOME" "$@"
+}
+
+# remove the '&> /dev/null' part if things don't seem to work right
+if dot checkout > /dev/null 2>&1; then
+   echo "Checked out dotfiles."
+else
+   echo "Backing up pre-existing dotfiles."
+   # get the list of files that need to be backed up
+   DOTFILES_BACKUP_LIST=($(dot checkout 2>&1 | grep -Po "\t.*$" | cut -c 1 --complement))
+   # create directories for everything that needs one 
+   mkdir -p $(printf '%s\n' "${DOTFILES_BACKUP_LIST[@]}" | grep -Po '.*/' | sed "s#.*#$DOTFILES_BACKUP_DIR/&#g")
+   # backup the files to avoid them being overwritten
+   printf '%s\n' "${DOTFILES_BACKUP_LIST[@]}" | xargs -I{} mv "$HOME"/{} "$DOTFILES_BACKUP_DIR"/{}
+fi
+
+dot checkout
+dot config status.showUntrackedFiles no
+