#!/bin/sh

# The directory the backups go in
BACKUPS=/home/user/backups
# The suffix of a backup file tar.gz for tar'd and gzip'd files
SUF=tar.gz
# Change to the directory Summink lives in
cd /home/user/talker

# Make sure the backups dir exists
mkdir -p $BACKUPS

# Just to make sure the tar file is there ...
sleep 30

# Check that the first bit went ok
if [ ! -f daily-backup.tar ]; then
   echo "Couldn't find tar file to compress!!!" >> logs/backup.log
   exit 1
fi

# Now compress the tar file to save disk space
gzip -9 daily-backup.tar

# And move it to somewhere safe...

# First check that the destination directory exists
if [ ! -d $BACKUPS ]; then
   mkdir $BACKUPS
   if [ ! -d $BACKUPS ]; then
      echo "Backups directory doens't exist, and I couldn't create it:-" \
         >> logs/backup.log
      echo "$BACKUPS" >> logs/backup.log
      exit 1
   fi
   echo "Created backup directory:-" >> logs/backup.log
   echo "$BACKUPS" >> logs/backup.log
fi

# The first number of the list '4 3 2 1' or whatever plus one is the
# number of daily backups you'll have at any one time (once they're filled)
for i in 4 3 2 1
do
   if [ -f $BACKUPS/weekly_backup.$i.$SUF ]; then
      mv -f $BACKUPS/weekly_backup.$i.$SUF $BACKUPS/weekly_backup.`expr $i + 1`.$SUF
   fi
done

# cp and rm, not mv, in case we have a dumb mv and we're 'moving' between
# different file systems.
cp daily-backup.$SUF $BACKUPS/weekly_backup.1.$SUF
rm daily-backup.$SUF
echo -n "Weekly backup completed at " >> logs/backup.log
echo `date` >> logs/backup.log