Shell Programming and Scripting

cd /var/lib/mysql/ || exit 1

gawk '
BEGIN {
   cmd = "mysql -u root -ppassword knowdatabases \"SELECT name, volume, date, description FROM testdatabase\""
   while ( cmd | getline ) {
      DATABASE[$1,1] = $2;
      DATABASE[$1,2] = $1;
   }
   close(cmd)
   
   cmd = "find /var/lib/mysql/ -maxdepth 1 -mindepth 1 -type d | xargs du -sm"
   while ( cmd | getline ) {
      VOL = $1;
      NAM = $2;
      if ( ! DATABASE[NAM,1] ) {
         print "There is no declared informations about " NAM " in table testdatabase."
      continue
      }
      if ( VOL > DATABASE[NAM,1] ) {
         print "Database " NAM " has too big actual size (" VOL "), it exceeds declared size in table testdatabase."
      continue
      }
   }
   close(cmd)
}
' /dev/null