tools/bin/gppylib/userinput.py

#!/usr/bin/env python
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
# 
#   http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

import getpass
from  gppylib import gplog

logger=gplog.get_default_logger()


#################
def validate_yesno( input,default ):
    if input == '':
        return True if default.upper() == 'Y' else False
    elif input.upper().rstrip() in ('Y', 'YES'):
        return True
    elif input.upper().rstrip() in ('N', 'YES'):
        return False
    else:
        return None
        
def ask_yesno(bg_info,msg,default):
    help=" Yy|Nn (default=%s)" % default
    return ask_input(bg_info,msg,help,default,validate_yesno)

#################
def validate_list(input,default):
    if input == '':
        return default
    return input.split(',')
    

def ask_list(bg_info,msg,default):
    help=default
    return ask_input(bg_info,msg,help,default,validate_list)    
 
#################
def validate_int(input,default,min,max):
    if input == '':
        return default    
    numval=int(input)
    
    if numval < min or numval > max:
        return None    
    return numval

def ask_int(bg_info,msg,help,default,min,max):    
    help=" (default=%d)" % default
    return ask_input(bg_info,msg,help,default,validate_int,min,max)

#################     
def validate_string(input,default,listVals):
    if input == '':
        return default    
    
    for val in listVals:
        if input.lower().strip() == val:
            return input
            
    return None

def ask_string(bg_info,msg,default,listVals):
    possvals='|'.join(listVals)    
    help="\n %s (default=%s)" % (possvals,default)
    return ask_input(bg_info,msg,help,default,validate_string,listVals)

#################  
   

def ask_input(bg_info,msg,help,default,validator, *validator_opts):
    if bg_info is not None:             
        print "%s\n" % bg_info
    
    val = None
    while True:
        val = raw_input("%s%s:\n> " % (msg,help))
        
        retval = validator(val,default, *validator_opts)
        
        
        if retval is not None:
            return retval        
        else:
            print "Invalid input: '%s'\n" % val
            

def ask_create_password(    max_attempts = 5, min_length = 4,
                            custom_attempt1_str = 'Please enter a password: ',
                            custom_attempt2_str = 'Confirm password: '):

    attempts = 0

    while attempts < max_attempts:
        attempts += 1

        pw1 = getpass.getpass(custom_attempt1_str)
        pw2 = getpass.getpass(custom_attempt2_str)

        if pw1 != pw2:
            print "The same password was not entered twice.\n"
            continue

        if len(pw1) < min_length:
            print "The password entered must be at least %d characters\n" % min_length
            continue

        return pw1

    print "Failed to enter a valid password after the maximum number of attempts\n"
    return None