--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/release/io.py	Sat Mar 21 17:12:07 2009 +0000
@@ -0,0 +1,144 @@
+#!/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
+
+"""User prompting and file access utilities."""
+
+__authors__ = [
+    # alphabetical order by last name, please
+    '"David Anderson" <dave@natulte.net>',
+    ]
+
+import error
+import log
+
+
+class Error(error.Error):
+  pass
+
+
+class FileAccessError(Error):
+  """An error occured while accessing a file."""
+  pass
+
+
+def getString(prompt):
+  """Prompt for and return a string."""
+  prompt += ' '
+  log.stdout.write(prompt)
+  log.stdout.flush()
+
+  response = sys.stdin.readline()
+  log.terminal_echo(prompt + response.strip())
+  if not response:
+    raise error.AbortedByUser('Aborted by ctrl+D')
+
+  return response.strip()
+
+
+def confirm(prompt, default=False):
+  """Ask a yes/no question and return the answer.
+
+  Will reprompt the user until one of "yes", "no", "y" or "n" is
+  entered. The input is case insensitive.
+
+  Args:
+    prompt: The question to ask the user.
+    default: The answer to return if the user just hits enter.
+
+  Returns:
+    True if the user answered affirmatively, False otherwise.
+  """
+  if default:
+    question = prompt + ' [Yn]'
+  else:
+    question = prompt + ' [yN]'
+  while True:
+    answer = getString(question)
+    if not answer:
+      return default
+    elif answer in ('y', 'yes'):
+      return True
+    elif answer in ('n', 'no'):
+      return False
+    else:
+      log.error('Please answer yes or no.')
+
+
+def getNumber(prompt):
+  """Prompt for and return a number.
+
+  Will reprompt the user until a number is entered.
+  """
+  while True:
+    value_str = getString(prompt)
+    try:
+      return int(value_str)
+    except ValueError:
+      log.error('Please enter a number. You entered "%s".' % value_str)
+
+
+def getChoice(intro, prompt, choices, done=None, suggest=None):
+  """Prompt for and return a choice from a menu.
+
+  Will reprompt the user until a valid menu entry is chosen.
+
+  Args:
+    intro: Text to print verbatim before the choice menu.
+    prompt: The prompt to print right before accepting input.
+    choices: The list of string choices to display.
+    done: If not None, the list of indices of previously
+      selected/completed choices.
+    suggest: If not None, the index of the choice to highlight as
+      the suggested choice.
+
+  Returns:
+    The index in the choices list of the selection the user made.
+  """
+  done = set(done or [])
+  while True:
+    print intro
+    print
+    for i, entry in enumerate(choices):
+      done_text = ' (done)' if i in done else ''
+      indent = '--> ' if i == suggest else '    '
+      print '%s%2d. %s%s' % (indent, i+1, entry, done_text)
+    print
+    choice = getNumber(prompt)
+    if 0 < choice <= len(choices):
+      return choice-1
+    log.error('%d is not a valid choice between %d and %d' %
+              (choice, 1, len(choices)))
+    print
+
+
+def fileToLines(path):
+  """Read a file and return it as a list of lines."""
+  try:
+    with file(path) as f:
+      return f.read().split('\n')
+  except (IOError, OSError), e:
+    raise FileAccessError(str(e))
+
+
+def linesToFile(path, lines):
+  """Write a list of lines to a file."""
+  try:
+    with file(path, 'w') as f:
+      f.write('\n'.join(lines))
+  except (IOError, OSError), e:
+    raise FileAccessError(str(e))