Trying to prevent myself from another home fiasco, I've decided to build a simple script to backup some of my directories. There are a lot of scripts / backup tools out there, but I just wanted to build my own for the fun of it, and since what I really wanted was to create a tar.gz of the contents of a specific directory (no root path), including hidden files, and without the need to support incremental backups. Take a look at the script:
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#!/bin/bash
	 
	function showHelp() {
	  if [ "$1" != "" ]; then
	    echo "ERROR: $1"
	    echo ""
	  fi
	 
	  echo "Usage: $0 <folder> <file.tar.gz>"
	  echo "where:"
	  echo "  <folder>  folder to backup"
	  echo "  <file.tar.gz>  where to save the backup (.tar.gz file)"
	}
	 
	if [ $# -ne 2 ]; then
	  showHelp
	elif [ ! -d "$1" ]; then
	  showHelp "Directory $1 does not exist"
	  exit 1
	else
	  echo -n "Creating $2 from $1: "
	 
	  if [ -f "$2" ]; then
	    mv "$2" "$2.previous"
	  fi
	 
	  tar -cpzf "$2" --exclude="$2" --ignore-failed-read --transform="s/"`echo "$1" | sed -e 's/^\\///g' | sed -e 's/\\/$//g' | sed s/\\\//'\\\\'\\\//g`"//" "$1" &>/dev/null
	 
	  if [ $? -ne 0 ]; then
	    echo "ERROR"
	    exit 1
	  else
	    echo "DONE"
	 
	    if [ -f "$2.previous" ]; then
	      rm -f "$2.previous"
	    fi
	  fi
	fi

========================
The line that probably looks scary is:

Code:
	tar -cpzf "$2" --exclude="$2" --ignore-failed-read --transform="s/"`echo "$1" | sed -e 's/^\\///g' | sed -e 's/\\/$//g' | sed s/\\\//'\\\\'\\\//g`"//" "$1" &>/dev/null

The complicated part comes from the transform expression, which is used to get rid of the absolute path to the directory we are backing up. The tar --directory option here is not useful since it adds the "." special path to the packaged file, so let's break it down:

    * echo "$1": the folder to backup
    * sed -e 's/^\\///g': remove starting slash, if any
    * sed -e 's/\\/$//g': remove trailing slash, if any
    * sed s/\\\//'\\\\'\\\//g`: convert forward slash to escaped slashes (so every / is replaced by \/)