diff --git a/BUGS.md b/BUGS.md
index 03ec903..eb3cfd9 100644
--- a/BUGS.md
+++ b/BUGS.md
@@ -1,9 +1,9 @@
 
 # BUGS
 
+- generators e correct scripts que durem muito tempo bloqueiam o eventloop do tornado.
 - change password modal nao aparece no ipad (safari e firefox)
 - on start topic, logs show questionhandler.get() twice.
-- generators e correct scripts que durem muito tempo podem bloquear o loop do tornado?
 - detect questions in questions.yaml without ref -> error ou generate default.
 - Criar outra estrutura organizada em capítulos (conjuntos de tópicos). Permitir capítulos de capítulos, etc. talvez usar grafos de grafos...
 - session management. close after inactive time.
diff --git a/addstudent.py b/addstudent.py
deleted file mode 100755
index d330ffe..0000000
--- a/addstudent.py
+++ /dev/null
@@ -1,53 +0,0 @@
-#!/usr/bin/env python3
-
-import csv
-import argparse
-import re
-import string
-from sys import exit
-
-import bcrypt
-from sqlalchemy import create_engine
-from sqlalchemy.orm import sessionmaker
-
-from models import Base, Student
-
-# ===========================================================================
-#   Parse command line options
-# ===========================================================================
-argparser = argparse.ArgumentParser(description='Add new student to database or update its password')
-argparser.add_argument('--db', default='students.db', type=str, help='database filename')
-argparser.add_argument('uid', type=str, default='', help='Student ID')
-argparser.add_argument('password', type=str, default='', help='Student password')
-argparser.add_argument('name', nargs='*', type=str, default='', help='Student name')
-args = argparser.parse_args()
-
-# =======================================================x====================
-engine = create_engine(f'sqlite:///{args.db}', echo=False)
-Base.metadata.create_all(engine)  # Criate schema if needed
-Session = sessionmaker(bind=engine)
-
-uid = args.uid
-password = bcrypt.hashpw(args.password.encode('utf-8'), bcrypt.gensalt())
-name = ' '.join(args.name)
-
-# --- start db session ---
-session = Session()
-
-u = session.query(Student).get(uid)
-
-if u is None:
-    session.add(Student(id=uid, name=name, password=password))
-    print(f'New user added to "{args.db}".')
-
-else:
-    print('Student already exists.')
-    if input('  Update password? [y/n] ') in ('y', 'yes', 'Y', 'Yes', 'YES'):
-        u.password = password
-        print('  Password updated.')
-    else:
-        print('  Nothing done.')
-
-session.commit()
-session.close()
-# --- end db session ---
diff --git a/demo/solar_system/questions.yaml b/demo/solar_system/questions.yaml
index cc21d04..9b1a702 100644
--- a/demo/solar_system/questions.yaml
+++ b/demo/solar_system/questions.yaml
@@ -40,8 +40,9 @@
     type: textarea
     title: Sistema solar
     text: Escreva o nome dos três planetas mais próximos do Sol. (Exemplo `A, B e C`)
-    correct: correct-first_3_planets.py
+    # correct: correct-first_3_planets.py
+    correct: correct-timeout.py
     # opcional
     answer: Vulcano, Krypton, Plutão
     lines: 3
-    timeout: 5
+    timeout: 50
diff --git a/initdb.py b/initdb.py
index b14d026..fc33923 100755
--- a/initdb.py
+++ b/initdb.py
@@ -31,113 +31,166 @@ async def hash_all_passwords(executor, students):
     await asyncio.wait(tasks)  # block until all tasks are done
     print()
 
+# ===========================================================================
 # SIIUE names have alien strings like "(TE)" and are sometimes capitalized
 # We remove them so that students dont keep asking what it means
 def fix(name):
     return string.capwords(re.sub('\(.*\)', '', name).strip())
 
+
 # ===========================================================================
 #   Parse command line options
 def parse_commandline_arguments():
     argparser = argparse.ArgumentParser(
-        description='Create new database from a CSV file (SIIUE format)')
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+        description='Insert new users into a database. Users can be imported from CSV files in the SIIUE format or defined in the command line. If the database does not exist, a new one is created.')
+
+    argparser.add_argument('csvfile',
+        nargs='*',
+        type=str,
+        default='',
+        help='CSV file to import (SIIUE)')
 
     argparser.add_argument('--db',
         default='students.db',
         type=str,
-        help='database filename')
+        help='database file')
 
-    argparser.add_argument('--demo',
+    argparser.add_argument('-A', '--admin',
         action='store_true',
-        help='initialize database with a few fake students')
+        help='insert the admin user')
+
+    argparser.add_argument('-a', '--add',
+        nargs=2,
+        action='append',
+        metavar=('uid', 'name'),
+        help='add new user')
+
+    argparser.add_argument('-u', '--update',
+        nargs='+',
+        metavar='uid',
+        default=[],
+        help='users to update')
 
     argparser.add_argument('--pw',
         default='',
         type=str,
-        help='default password')
+        help='set password for new and updated users')
 
-    argparser.add_argument('csvfile',
-        nargs='?',
-        type=str,
-        default='',
-        help='CSV filename')
+    argparser.add_argument('-V', '--verbose',
+        action='store_true',
+        help='show all students in database')
 
     return argparser.parse_args()
 
+
 # ===========================================================================
 def get_students_from_csv(filename):
     try:
         csvreader = csv.DictReader(open(filename, encoding='iso-8859-1'), delimiter=';', quotechar='"', skipinitialspace=True)
     except EnvironmentError:
-        print(f'Error: CSV file "{filename}" not found.')
-        exit(1)
-    students = [{
-        'uid': s['N.º'],
-        'name': fix(s['Nome'])
-        } for s in csvreader]
+        print(f'!!! Error. File "{filename}" not found !!!')
+        students = []
+    else:
+        students = [{
+            'uid': s['N.º'],
+            'name': fix(s['Nome'])
+            } for s in csvreader]
 
     return students
 
+
 # ===========================================================================
-args = parse_commandline_arguments()
-
-if args.csvfile:
-    students = get_students_from_csv(args.csvfile)
-elif args.demo:
-    students = [
-        {'uid': '1915', 'name': 'Alan Turing'},
-        {'uid': '1938', 'name': 'Donald Knuth'},
-        {'uid': '1815', 'name': 'Ada Lovelace'},
-        {'uid': '1969', 'name': 'Linus Torvalds'},
-        {'uid': '1955', 'name': 'Tim Burners-Lee'},
-        {'uid': '1916', 'name': 'Claude Shannon'},
-        {'uid': '1903', 'name': 'John von Neumann'}]
-students.append({'uid': '0', 'name': 'Admin'})
-
-if args.pw:
-    for s in students:
-        s['pw'] = args.pw
-
-print(f'Generating {len(students)} bcrypt password hashes.')
-executor = ThreadPoolExecutor()
-event_loop = asyncio.get_event_loop()
-event_loop.run_until_complete(hash_all_passwords(executor, students))
-event_loop.close()
-
-print(f'Creating database: {args.db}')
-engine = sa.create_engine(f'sqlite:///{args.db}', echo=False)
-Base.metadata.create_all(engine)  # Criate schema if needed
-Session = sa.orm.sessionmaker(bind=engine)
-
-try:
-    # --- start db session ---
+def insert_students_into_db(session, students):
+    try:
+        # --- start db session ---
+        session.add_all([Student(id=s['uid'], name=s['name'], password=s['pw'])
+            for s in students])
+
+        session.commit()
+
+    except sa.exc.IntegrityError:
+        print('!!! Integrity error. User(s) already in database. None inserted !!!\n')
+        session.rollback()
+
+
+# ===========================================================================
+def show_students_in_database(session, verbose=False):
+    try:
+        users = session.query(Student).order_by(Student.id).all()
+    except:
+        raise
+    else:
+        n = len(users)
+        print(f'Users registered:')
+        if n == 0:
+            print('  -- none --')
+        else:
+            if verbose:
+                for u in users:
+                    print(f'{u.id:>12}   {u.name}')
+            else:
+                print(f'{users[0].id:>12}   {users[0].name}')
+                if n > 1:
+                    print(f'{users[1].id:>12}   {users[1].name}')
+                if n > 3:
+                    print('           |   |')
+                if n > 2:
+                    print(f'{users[-1].id:>12}   {users[-1].name}')
+        print(f'Total: {n}.')
+
+
+# ===========================================================================
+if __name__=='__main__':
+    args = parse_commandline_arguments()
+
+    # --- make list of students to insert/update
+    students = []
+
+    for csvfile in args.csvfile:
+        print('Adding users from:', csvfile)
+        students.extend(get_students_from_csv(csvfile))
+
+    if args.admin:
+        print('Adding user: 0, admin.')
+        students.append({'uid': '0', 'name': 'Admin'})
+
+    if args.add:
+        for uid, name in args.add:
+            print(f'Adding user: {uid}, {name}.')
+            students.append({'uid': uid, 'name': name})
+
+    # --- password hashing
+    if students:
+        print(f'Generating password hashes (bcrypt).')
+        if args.pw:  # maybe set default password
+            for s in students:
+                s['pw'] = args.pw
+
+        executor = ThreadPoolExecutor()
+        event_loop = asyncio.get_event_loop()
+        event_loop.run_until_complete(hash_all_passwords(executor, students))
+        event_loop.close()
+
+    # --- database stuff
+    print(f'Using database: ', args.db)
+    engine = sa.create_engine(f'sqlite:///{args.db}', echo=False)
+    Base.metadata.create_all(engine)  # Criate schema if needed
+    Session = sa.orm.sessionmaker(bind=engine)
     session = Session()
 
-    session.add_all([Student(id=s['uid'], name=s['name'], password=s['pw'])
-        for s in students])
-
-    n = session.query(Student).count()
-    print(f'{n} user(s):')
-
-    users = session.query(Student).order_by(Student.id).all()
-    print(f'    {users[0].id:8} - {users[0].name} (administrator)')
-    if n > 1:
-        print(f'    {users[1].id:8} - {users[1].name}')
-    if n > 3:
-        print('    ...        ...')
-    if n > 2:
-        print(f'    {users[-1].id:8} - {users[-1].name}')
-
-except sa.exc.IntegrityError:
-    print('!!! Integrity error !!!')
-    session.rollback()
-
-except Exception as e:
-    print(f'Error: Database "{args.db}" already exists?')
-    session.rollback()
-    raise e
-    # exit(1)
-
-else:
-    # --- end session ---
-    session.commit()
+    if students:
+        print(f'Inserting {len(students)}')
+        insert_students_into_db(session, students)
+
+    # print(args.update)
+    for s in args.update:
+        print(f'Updating password of: {s}')
+        u = session.query(Student).get(s)
+        pw =(args.pw or s).encode('utf-8')
+        u.password = bcrypt.hashpw(pw, bcrypt.gensalt())
+        session.commit()
+
+    show_students_in_database(session, args.verbose)
+
+    session.close()
diff --git a/tools.py b/tools.py
index b4d0607..f45a110 100644
--- a/tools.py
+++ b/tools.py
@@ -154,6 +154,8 @@ def load_yaml(filename, default=None):
 
 # ---------------------------------------------------------------------------
 # Runs a script and returns its stdout parsed as yaml, or None on error.
+# The script is run in another process but this function blocks waiting
+# for its termination.
 # ---------------------------------------------------------------------------
 def run_script(script, stdin='', timeout=5):
     script = path.expanduser(script)
--
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