#!/bin/sh
#
# Home directory automatic backup script
#
# Autor: Adam Drzewiecki
# e-mail: A.Drzewiecki@ztpnet.pl
# Last modified: 13 Nov 2008
#

#
# Configuration
#

# Backup file folder (it must not be in backuped content)
BACKUP_DIR="/root/backup"
# Archive format: "gz" or "bz2"
FORMAT="bz2"
# Save last "PRESERVE" backup copies
PRESERVE="2"
# Backuped content
BACKED_UP="/home"

# Base part of the backup filename
BASE="home-backup-"
# Filename format (default: home-backup-RRRRMMDD)
FILENAME="${BASE}$(date +%Y%m%d)"

# Archiver
CMD="tar"

#
# Working part of the script
#

# Build filename and commandline from configuration variables
case $FORMAT in
    bz2)
	SUFFIX="tar.bz2"
	OPTIONS="jcf"
	;;
	
    gz)
	SUFFIX="tar.gz"
	OPTIONS="zcf"
	;;
	
    *)
	echo "$(date):"
	echo "Script $(basename $0): unknown archive format ($FORMAT)."
	echo
	exit 1
	;;
esac

# Fullname of archive file
FULLNAME="$BACKUP_DIR/$FILENAME.$SUFFIX"
# Archiver commandline
CMDLINE="$CMD $OPTIONS $FULLNAME $BACKED_UP"
# Archive files mask
MASK="${BASE}*.$SUFFIX"

# If archive folder doesn't exist...
if [ ! -d "$BACKUP_DIR" ]; then
    # ...try to make it with needed parent directories
    if (mkdir -p $BACKUP_DIR) then
	# OK message
	echo "$(date):"
	echo "Script $(basename $0): folder $BACKUP_DIR has been made"
	echo
    else
	# Emit failure message, terminate script with error code
	echo "$(date):"
	echo "Script $(basename $0): folder $BACKUP_DIR HASN'T been made"
	echo
	exit 1
    fi
fi

# Do the new backup file if backup from today doesn't exist
if [ ! -f "$FULLNAME" ]; then
    # Inform administrator about commandline
    echo "$(date):"
    echo "Script $(basename $0): launching archivisation command:"
    echo "$CMDLINE"
    echo

    # Launch prepared CMDLINE    
    if ($CMDLINE) then
	#
	# Success
	#
	echo
	echo "$(date):"
	echo "Script $(basename $0): created new backup file:"
	echo
	echo "$(ls -lh $FULLNAME)"
	echo
	    
    else
	#
	# Failed. Cleaning up
	#
	echo
	echo "$(date):"
	echo "Script $(basename $0): there was an error during creation of $FULLNAME"
	echo
	
	#
	# Removing created archive file, if it exists
	#
	if [ -f "$FULLNAME" ]; then
	    # Removing archive file
	    if (rm "$FULLNAME") then
		# Success
		echo "File $FULLNAME has been removed."
		echo
	    else
		# Failure
		echo "File $FULLNAME HASN'T been removed!"
		echo
	    fi
	fi
	    
	# There was an error, terminate script
	exit 1
    fi
	
    #
    # New backup file has been created. Removing old backup files
    #
	
    # List of last PRESERVE backup files
    SAVE="$(ls -1 $BACKUP_DIR/$MASK | tail -n $PRESERVE)"

    # Generating information for administrator
    echo "Cleaning up backup files folder:"
    
    # For every backup file structured file in the backup files folder... 
    for FILE in $BACKUP_DIR/$MASK; do
    	# ... test if it isn't in the preserved files list
	if (! echo $SAVE | grep -q $FILE) then
	    # Start memo line about deleting file
	    echo -n "File $FILE: "
		
	    # Try to remove file
	    if (rm "$FILE") then
		echo "has been deleted"
	    else
		echo "HASN't been deleted!"
	    fi
	else
	    # File is one of saved backup files
	    echo "File $FILE: preserved"
	fi
    done
fi