Bash script to calculate MySQL table dimensions on disk

mysql-table-size-ondisk.sh

#!/bin/bash
(
    mysql_datadir=$(grep datadir /etc/my.cnf | head -n 1 | cut -d "=" -f 2 | cut -d "#" -f 1)
    cd $mysql_datadir
    for frm_file in $(find . -name "*.frm" | egrep -v "[.]/(mysql|sys|performance_schema|common_schema)")
    do
        table_schema=$(echo $frm_file | cut -d "/" -f 2)
        table_name=$(echo $frm_file | cut -d "/" -f 3 | cut -d "." -f 1)

        if [ -f ${frm_file//.frm/.MYD} ]; then
            # A MyISAM table
            # This script only supports an unpartitioned table
            file_size=$(du -cb ${frm_file//.frm/.MY?} 2> /dev/null | tail -n 1)
        elif [ -f ${frm_file//.frm/.ARZ} ]; then
            # An ARCHIVE table
            # This script only supports an unpartitioned table
            file_size=$(du -cb ${frm_file//.frm/.ARZ} 2> /dev/null | tail -n 1)
        else
            # Is this InnoDB?
            tbl_file=${frm_file//.frm/.ibd}
            if [ -f $tbl_file ]
            then
                # unpartitioned table
                file_size=$(du -cb $tbl_file 2> /dev/null | tail -n 1)
            else
                # attempt partitioned innodb table
                # Yeah, maybe this isn't InnoDB at all, and this clause also catches that. Oh, well...
                tbl_file_partitioned=${frm_file//.frm/#*.ibd}
                file_size=$(du -cb $tbl_file_partitioned 2> /dev/null | tail -n 1)
            fi
        fi
        file_size=${file_size//total/}

        echo "$table_schema.$table_name" $file_size
    done
) | sort -k 2 -nr | head -n 100 | while read entry size
do
  echo $entry $size
done