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1 #!/usr/bin/python2.5 |
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2 # |
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3 # Copyright 2009 the Melange authors. |
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4 # |
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5 # Licensed under the Apache License, Version 2.0 (the "License"); |
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6 # you may not use this file except in compliance with the License. |
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7 # You may obtain a copy of the License at |
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8 # |
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9 # http://www.apache.org/licenses/LICENSE-2.0 |
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10 # |
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11 # Unless required by applicable law or agreed to in writing, software |
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12 # distributed under the License is distributed on an "AS IS" BASIS, |
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13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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14 # See the License for the specific language governing permissions and |
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15 # limitations under the License. |
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16 |
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17 from __future__ import with_statement |
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18 |
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19 """User prompting and file access utilities.""" |
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20 |
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21 __authors__ = [ |
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22 # alphabetical order by last name, please |
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23 '"David Anderson" <dave@natulte.net>', |
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24 ] |
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25 |
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26 import error |
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27 import log |
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28 |
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29 |
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30 class Error(error.Error): |
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31 pass |
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32 |
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33 |
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34 class FileAccessError(Error): |
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35 """An error occured while accessing a file.""" |
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36 pass |
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37 |
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38 |
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39 def getString(prompt): |
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40 """Prompt for and return a string.""" |
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41 prompt += ' ' |
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42 log.stdout.write(prompt) |
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43 log.stdout.flush() |
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44 |
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45 response = sys.stdin.readline() |
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46 log.terminal_echo(prompt + response.strip()) |
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47 if not response: |
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48 raise error.AbortedByUser('Aborted by ctrl+D') |
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49 |
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50 return response.strip() |
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51 |
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52 |
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53 def confirm(prompt, default=False): |
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54 """Ask a yes/no question and return the answer. |
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55 |
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56 Will reprompt the user until one of "yes", "no", "y" or "n" is |
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57 entered. The input is case insensitive. |
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58 |
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59 Args: |
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60 prompt: The question to ask the user. |
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61 default: The answer to return if the user just hits enter. |
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62 |
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63 Returns: |
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64 True if the user answered affirmatively, False otherwise. |
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65 """ |
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66 if default: |
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67 question = prompt + ' [Yn]' |
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68 else: |
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69 question = prompt + ' [yN]' |
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70 while True: |
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71 answer = getString(question) |
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72 if not answer: |
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73 return default |
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74 elif answer in ('y', 'yes'): |
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75 return True |
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76 elif answer in ('n', 'no'): |
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77 return False |
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78 else: |
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79 log.error('Please answer yes or no.') |
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80 |
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81 |
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82 def getNumber(prompt): |
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83 """Prompt for and return a number. |
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84 |
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85 Will reprompt the user until a number is entered. |
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86 """ |
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87 while True: |
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88 value_str = getString(prompt) |
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89 try: |
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90 return int(value_str) |
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91 except ValueError: |
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92 log.error('Please enter a number. You entered "%s".' % value_str) |
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93 |
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94 |
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95 def getChoice(intro, prompt, choices, done=None, suggest=None): |
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96 """Prompt for and return a choice from a menu. |
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97 |
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98 Will reprompt the user until a valid menu entry is chosen. |
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99 |
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100 Args: |
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101 intro: Text to print verbatim before the choice menu. |
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102 prompt: The prompt to print right before accepting input. |
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103 choices: The list of string choices to display. |
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104 done: If not None, the list of indices of previously |
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105 selected/completed choices. |
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106 suggest: If not None, the index of the choice to highlight as |
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107 the suggested choice. |
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108 |
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109 Returns: |
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110 The index in the choices list of the selection the user made. |
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111 """ |
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112 done = set(done or []) |
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113 while True: |
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114 print intro |
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115 print |
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116 for i, entry in enumerate(choices): |
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117 done_text = ' (done)' if i in done else '' |
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118 indent = '--> ' if i == suggest else ' ' |
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119 print '%s%2d. %s%s' % (indent, i+1, entry, done_text) |
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120 print |
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121 choice = getNumber(prompt) |
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122 if 0 < choice <= len(choices): |
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123 return choice-1 |
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124 log.error('%d is not a valid choice between %d and %d' % |
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125 (choice, 1, len(choices))) |
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126 print |
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127 |
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128 |
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129 def fileToLines(path): |
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130 """Read a file and return it as a list of lines.""" |
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131 try: |
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132 with file(path) as f: |
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133 return f.read().split('\n') |
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134 except (IOError, OSError), e: |
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135 raise FileAccessError(str(e)) |
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136 |
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137 |
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138 def linesToFile(path, lines): |
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139 """Write a list of lines to a file.""" |
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140 try: |
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141 with file(path, 'w') as f: |
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142 f.write('\n'.join(lines)) |
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143 except (IOError, OSError), e: |
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144 raise FileAccessError(str(e)) |