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     > Backing up MySQL databases (snapshot)

There are fixed settings that I use to backup my MySQL databases. There are quite a few that need to be backed up, so I wrote the following script:

#!/bin/sh
DATE=`date '+%Y_%m_%d-%H-%M-%S'`; # date to use in filename
WORKING_DIR=`dirname $0`;

doBackup ()
{
    for ARG in "$@"
    do
      echo "Backing up "$ARG;
      #if the file has not changed since the last time a snapshot was taken, do not create another file..
      if [ ! -d $WORKING_DIR"/mysqlDump/$ARG/" ]
        then
        mkdir $WORKING_DIR"/mysqlDump/$ARG/";
      fi
      MOST_RECENT_FILE=$WORKING_DIR"/mysqlDump/$ARG/"`ls -t $WORKING_DIR"/mysqlDump/$ARG" | head -n 1`;
      mysqldump --add-drop-table --routines --user=rdy --password=lamepass --skip-dump-date $ARG > $WORKING_DIR"/mysqlDump/$ARG/$ARG""_"$DATE".sql";
      if [ ! -d $MOST_RECENT_FILE ]
        then
          STRING=`cmp $WORKING_DIR"/mysqlDump/$ARG/$ARG""_"$DATE".sql" $MOST_RECENT_FILE`;
          if [ -z "$STRING" ]
          then
            rm $WORKING_DIR"/mysqlDump/$ARG/$ARG""_"$DATE".sql";
          fi
      fi
    done
}

doBackup "rdyweb" "Clicker" "apartment"
sleep 3;

It's really pretty simple - it does the following:

1. find out what the working directory is (where the script is executed from) and uses that as the path to work with
2. checks to see if a folder exists for the database - if it doesn't, will create one
3. find out what the most recently modified file in the folder for the database in question is
4. dump the database (this is for comparison)
5. compare the most recent one to the one that has just been created - if they match then remove the one that has just been created
6. done