+
−#!/usr/bin/python2.5
+
−#
+
−# Copyright 2009 the Melange authors.
+
−#
+
−# Licensed 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.
+
−
+
−from __future__ import with_statement
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−
+
−"""User prompting and file access utilities."""
+
−
+
−__authors__ = [
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−    # alphabetical order by last name, please
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−    '"David Anderson" <dave@natulte.net>',
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−    ]
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−
+
−import error
+
−import log
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−
+
−
+
−class Error(error.Error):
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−  pass
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−
+
−
+
−class FileAccessError(Error):
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−  """An error occured while accessing a file."""
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−  pass
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−
+
−
+
−def getString(prompt):
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−  """Prompt for and return a string."""
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−  prompt += ' '
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−  log.stdout.write(prompt)
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−  log.stdout.flush()
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−
+
−  response = sys.stdin.readline()
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−  log.terminal_echo(prompt + response.strip())
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−  if not response:
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−    raise error.AbortedByUser('Aborted by ctrl+D')
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−
+
−  return response.strip()
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−
+
−
+
−def confirm(prompt, default=False):
+
−  """Ask a yes/no question and return the answer.
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−
+
−  Will reprompt the user until one of "yes", "no", "y" or "n" is
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−  entered. The input is case insensitive.
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−
+
−  Args:
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−    prompt: The question to ask the user.
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−    default: The answer to return if the user just hits enter.
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−
+
−  Returns:
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−    True if the user answered affirmatively, False otherwise.
+
−  """
+
−  if default:
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−    question = prompt + ' [Yn]'
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−  else:
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−    question = prompt + ' [yN]'
+
−  while True:
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−    answer = getString(question)
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−    if not answer:
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−      return default
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−    elif answer in ('y', 'yes'):
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−      return True
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−    elif answer in ('n', 'no'):
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−      return False
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−    else:
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−      log.error('Please answer yes or no.')
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−
+
−
+
−def getNumber(prompt):
+
−  """Prompt for and return a number.
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−
+
−  Will reprompt the user until a number is entered.
+
−  """
+
−  while True:
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−    value_str = getString(prompt)
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−    try:
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−      return int(value_str)
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−    except ValueError:
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−      log.error('Please enter a number. You entered "%s".' % value_str)
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−
+
−
+
−def getChoice(intro, prompt, choices, done=None, suggest=None):
+
−  """Prompt for and return a choice from a menu.
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−
+
−  Will reprompt the user until a valid menu entry is chosen.
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−
+
−  Args:
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−    intro: Text to print verbatim before the choice menu.
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−    prompt: The prompt to print right before accepting input.
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−    choices: The list of string choices to display.
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−    done: If not None, the list of indices of previously
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−      selected/completed choices.
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−    suggest: If not None, the index of the choice to highlight as
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−      the suggested choice.
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−
+
−  Returns:
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−    The index in the choices list of the selection the user made.
+
−  """
+
−  done = set(done or [])
+
−  while True:
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−    print intro
+
−    print
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−    for i, entry in enumerate(choices):
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−      done_text = ' (done)' if i in done else ''
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−      indent = '--> ' if i == suggest else '    '
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−      print '%s%2d. %s%s' % (indent, i+1, entry, done_text)
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−    print
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−    choice = getNumber(prompt)
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−    if 0 < choice <= len(choices):
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−      return choice-1
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−    log.error('%d is not a valid choice between %d and %d' %
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−              (choice, 1, len(choices)))
+
−    print
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−
+
−
+
−def fileToLines(path):
+
−  """Read a file and return it as a list of lines."""
+
−  try:
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−    with file(path) as f:
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−      return f.read().split('\n')
+
−  except (IOError, OSError), e:
+
−    raise FileAccessError(str(e))
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−
+
−
+
−def linesToFile(path, lines):
+
−  """Write a list of lines to a file."""
+
−  try:
+
−    with file(path, 'w') as f:
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−      f.write('\n'.join(lines))
+
−  except (IOError, OSError), e:
+
−    raise FileAccessError(str(e))