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920dae64 AT |
1 | """Handle command line arguments. |
2 | ||
3 | This module contains functions to parse and access the arguments given | |
4 | to the program on the command line. | |
5 | """ | |
6 | ||
7 | import types | |
8 | import string | |
9 | import sys | |
10 | ||
11 | # Symbolic constants for the indexes into an argument specifier tuple. | |
12 | NAME = 0 | |
13 | MANDATORY = 1 | |
14 | TYPE = 2 | |
15 | HELP = 3 | |
16 | DEFAULT = 4 | |
17 | SPEC_LENGTH = 5 | |
18 | ||
19 | Bool = [] | |
20 | ||
21 | helpSpec = ( | |
22 | ('help', 0, Bool, 'print help and exit'), | |
23 | ) | |
24 | ||
25 | def parseArgs(title, argv, argSpecs, filesOK): | |
26 | """Parse and check command line arguments. | |
27 | ||
28 | Scan the command line arguments in *argv* according to the argument | |
29 | specifier *argSpecs*. Return **None** if there are no errors in | |
30 | the arguments, otherwise return an error string describing the error. | |
31 | ||
32 | This function must be called to initialise this module. | |
33 | ||
34 | title -- The name of the program. This is used when returning | |
35 | error messages or help text. | |
36 | ||
37 | argv -- A sequence containing the arguments given to the program. | |
38 | Normally **sys.argv**. | |
39 | ||
40 | argSpecs -- A sequence of argument specifiers. Each specifier describes | |
41 | a valid command line argument and consists of 4 or 5 items: | |
42 | ||
43 | - The argument name (without a leading minus sign **-**). | |
44 | ||
45 | - A boolean value, true if the argument is mandatory. | |
46 | ||
47 | - This should be **Args.Bool** if the argument has no option. | |
48 | Otherwise it should be a string describing the option | |
49 | required for this argument. This is used when printing help. | |
50 | ||
51 | - A short string describing the argument. | |
52 | ||
53 | - The default value of the argument. This should only be used | |
54 | for non-mandatory arguments expecting an option. | |
55 | ||
56 | For example: | |
57 | ( | |
58 | ('foreground', 0, 'colour', 'colour of text', 'black'), | |
59 | ('geometry', 0, 'spec', 'geometry of initial window'), | |
60 | ('server', 1, 'ompserver', 'ompserver to connect to'), | |
61 | ('silent', 0, Args.Bool, 'do not sound bell'), | |
62 | ) | |
63 | """ | |
64 | ||
65 | global programName | |
66 | global _fileList | |
67 | ||
68 | errMsg = title + ' command line error: ' | |
69 | programName = argv[0]; | |
70 | ||
71 | argSpecs = helpSpec + argSpecs | |
72 | argSpecDic = {} | |
73 | for spec in argSpecs: | |
74 | arg = spec[NAME] | |
75 | argSpecDic[arg] = spec | |
76 | if len(spec) >= SPEC_LENGTH: | |
77 | set(arg, spec[DEFAULT]) | |
78 | elif spec[TYPE] is Bool: | |
79 | set(arg, 0) | |
80 | else: | |
81 | set(arg, None) | |
82 | ||
83 | knownKeys = argSpecDic.keys() | |
84 | ||
85 | i = 1 | |
86 | _fileList = [] | |
87 | argc = len(argv) | |
88 | while i < argc: | |
89 | arg = argv[i] | |
90 | key = arg[1:] | |
91 | if key in knownKeys: | |
92 | spec = argSpecDic[key] | |
93 | if spec[TYPE] is Bool: | |
94 | set(key, 1) | |
95 | else: | |
96 | i = i + 1 | |
97 | if i >= argc: | |
98 | return errMsg + 'missing argument to \'' + arg + '\' option.' | |
99 | value = argv[i] | |
100 | if len(spec) >= SPEC_LENGTH: | |
101 | try: | |
102 | if type(spec[DEFAULT]) == types.IntType: | |
103 | typeStr = 'integer' | |
104 | value = string.atoi(value) | |
105 | elif type(spec[DEFAULT]) == types.FloatType: | |
106 | typeStr = 'float' | |
107 | value = string.atof(value) | |
108 | except: | |
109 | sys.exc_traceback = None # Clean up object references | |
110 | return errMsg + 'cannot convert string \'' + value + \ | |
111 | '\' to ' + typeStr + ' for option \'-' + key + '\'.' | |
112 | set(key, value) | |
113 | else: | |
114 | _fileList.append(arg) | |
115 | i = i + 1 | |
116 | ||
117 | if get('help'): | |
118 | return _helpString(title, argSpecs) | |
119 | ||
120 | if not filesOK and len(_fileList) > 0: | |
121 | if len(_fileList) == 1: | |
122 | return errMsg + 'unknown option \'' + str(_fileList[0]) + '\'.' | |
123 | else: | |
124 | return errMsg + 'unknown options ' + str(_fileList) + '.' | |
125 | ||
126 | ||
127 | _missing = [] | |
128 | for spec in argSpecs: | |
129 | if spec[MANDATORY] and get(spec[NAME]) is None: | |
130 | _missing.append(spec[NAME]) | |
131 | if len(_missing) == 1: | |
132 | return errMsg + 'required argument \'-' + \ | |
133 | str(_missing[0]) + '\' is missing.' | |
134 | elif len(_missing) > 1: | |
135 | return errMsg + 'required arguments ' + \ | |
136 | str(map(lambda s: '-' + s, _missing)) + ' are missing.' | |
137 | ||
138 | return None | |
139 | ||
140 | def fileList(): | |
141 | return _fileList | |
142 | ||
143 | def _helpString(title, argSpecs): | |
144 | max = 0 | |
145 | for spec in argSpecs: | |
146 | if spec[TYPE] is Bool: | |
147 | width = len(spec[NAME]) + 1 | |
148 | else: | |
149 | width = len(spec[NAME]) + 4 + len(spec[TYPE]) | |
150 | if width > max: | |
151 | max = width | |
152 | ||
153 | rtn = title + ' command line arguments:' | |
154 | format = '\n %-' + str(max) + 's %s' | |
155 | for mandatory in (1, 0): | |
156 | needHeader = 1 | |
157 | for spec in argSpecs: | |
158 | if mandatory and spec[MANDATORY] or not mandatory and not spec[MANDATORY]: | |
159 | if needHeader: | |
160 | if mandatory: | |
161 | rtn = rtn + '\n Mandatory arguments:' | |
162 | else: | |
163 | rtn = rtn + '\n Optional arguments (defaults in parentheses):' | |
164 | needHeader = 0 | |
165 | if spec[TYPE] is Bool: | |
166 | arg = '-%s' % spec[NAME] | |
167 | else: | |
168 | arg = '-%s <%s>' % (spec[NAME], spec[TYPE]) | |
169 | if len(spec) >= SPEC_LENGTH: | |
170 | if type(spec[DEFAULT]) == types.StringType: | |
171 | definition = spec[HELP] + ' (' + spec[DEFAULT] + ')' | |
172 | else: | |
173 | definition = spec[HELP] + ' (' + str(spec[DEFAULT]) + ')' | |
174 | else: | |
175 | definition = spec[HELP] | |
176 | rtn = rtn + format % (arg, definition) | |
177 | ||
178 | return rtn | |
179 | ||
180 | def exists(key): | |
181 | return configDict.has_key(key) | |
182 | ||
183 | def get(key): | |
184 | return configDict[key] | |
185 | ||
186 | def set(key, value): | |
187 | global configDict | |
188 | ||
189 | configDict[key] = value | |
190 | ||
191 | configDict = {} |