Count MongoDB documents in all collections

count_documents.sh

#!/bin/bash

db_name="$1"

if [ -z "$db_name" ]; then
  echo "Usage: $0 <db_name or uri>"
  exit 1
else
  echo "Collections in db: $db_name."

  mongo --quiet "$db_name" <<EOF
    var collections = db.getCollectionNames();
    for(var i = 0; i < collections.length; i++) {
      var name = collections[i];
      if(name.substr(0, 6) != 'system')
        print(name + ': ' + db[name].count() + ' documents');
    }
    quit();
EOF
fi