1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
|
# A mini-language for parsing files. This is only used file the ParsedFile
# provider, but it makes more sense to split it out so it's easy to maintain
# in one place.
#
# You can use this module to create simple parser/generator classes. For instance,
# the following parser should go most of the way to parsing /etc/passwd:
#
# class Parser
# include Puppet::Util::FileParsing
# record_line :user, :fields => %w{name password uid gid gecos home shell},
# :separator => ":"
# end
#
# You would use it like this:
#
# parser = Parser.new
# lines = parser.parse(File.read("/etc/passwd"))
#
# lines.each do |type, hash| # type will always be :user, since we only have one
# p hash
# end
#
# Each line in this case would be a hash, with each field set appropriately.
# You could then call 'parser.to_line(hash)' on any of those hashes to generate
# the text line again.
module Puppet::Util::FileParsing
include Puppet::Util
attr_writer :line_separator, :trailing_separator
# Clear all existing record definitions. Only used for testing.
def clear_records
@record_types.clear
@record_order.clear
end
def fields(type)
type = symbolize(type)
if @record_types.include?(type)
@record_types[type][:fields].dup
else
nil
end
end
# Try to match a specific text line.
def handle_text_line(line, hash)
if line =~ hash[:match]
return {:record_type => hash[:name], :line => line}
else
return nil
end
end
# Try to match a record.
def handle_record_line(line, hash)
if method = hash[:method]
if ret = send(method, line.dup)
ret[:record_type] = hash[:name]
return ret
else
return nil
end
elsif regex = hash[:match]
raise "Cannot use matches to handle records yet"
# In this case, we try to match the whole line and then use the
# match captures to get our fields.
if match = regex.match(line)
fields = []
ignore = hash[:ignore] || []
p match.captures
match.captures.each_with_index do |value, i|
fields << value unless ignore.include? i
end
p fields
nil
else
Puppet.info "Did not match %s" % line
nil
end
else
ret = {}
sep = hash[:separator]
# String "helpfully" replaces ' ' with /\s+/ in splitting, so we
# have to work around it.
if sep == " "
sep = / /
end
hash[:fields].zip(line.split(sep)) do |param, value|
if value and value != ""
ret[param] = value
else
ret[param] = :absent
end
end
ret[:record_type] = hash[:name]
return ret
end
end
def line_separator
unless defined?(@line_separator)
@line_separator = "\n"
end
@line_separator
end
# Split text into separate lines using the record separator.
def lines(text)
# Remove any trailing separators, and then split based on them
text.sub(/#{self.line_separator}\Q/,'').split(self.line_separator)
end
# Split a bunch of text into lines and then parse them individually.
def parse(text)
lines(text).collect do |line|
parse_line(line)
end
end
# Handle parsing a single line.
def parse_line(line)
unless records?
raise Puppet::DevError, "No record types defined; cannot parse lines"
end
@record_order.each do |name|
hash = @record_types[name]
unless hash
raise Puppet::DevError, "Did not get hash for %s: %s" %
[name, @record_types.inspect]
end
method = "handle_%s_line" % hash[:type]
if respond_to?(method)
if result = send(method, line, hash)
return result
end
else
raise Puppet::DevError, "Somehow got invalid line type %s" % hash[:type]
end
end
return nil
end
# Define a new type of record. These lines get split into hashes. Valid
# options are:
# * <tt>:absent</tt>: What to use when a field is absent. Defaults to "".
# * <tt>:fields</tt>: The list of fields, as an array. By default, all
# fields are considered required.
# * <tt>:joiner</tt>: How to join fields together. Defaults to '\t'.
# * <tt>:optional</tt>: Which fields are optional. If these are missing,
# you'll just get the 'absent' value instead of an ArgumentError.
# * <tt>:rts</tt>: Whether to remove trailing whitespace. Defaults to false.
# If true, whitespace will be removed; if a regex, then whatever matches
# the regex will be removed.
# * <tt>:separator</tt>: The record separator. Defaults to /\s+/.
def record_line(name, options, &block)
unless options.include?(:fields)
raise ArgumentError, "Must include a list of fields"
end
invalidfields = [:record_type, :target, :on_disk]
options[:fields] = options[:fields].collect do |field|
r = symbolize(field)
if invalidfields.include?(r)
raise ArgumentError.new("Cannot have fields named %s" % r)
end
r
end
options[:absent] ||= ""
if options[:optional]
options[:optional] = options[:optional].collect { |f| symbolize(f) }
else
options[:optional] = []
end
options[:separator] ||= /\s+/
# Unless they specified a string-based joiner, just use a single
# space as the join value.
unless options[:separator].is_a?(String) or options[:joiner]
options[:joiner] = " "
end
if block_given?
method = "handle_record_line_%s" % name
if respond_to?(method)
raise "Already have a method defined for this record"
end
meta_def(method, &block)
options[:method] = method
end
new_line_type(name, :record, options)
end
# Are there any record types defined?
def records?
defined?(@record_types) and ! @record_types.empty?
end
# Define a new type of text record.
def text_line(name, options)
unless options.include?(:match)
raise ArgumentError, "You must provide a :match regex for text lines"
end
new_line_type(name, :text, options)
end
# Generate a file from a bunch of hash records.
def to_file(records)
text = records.collect { |record| to_line(record) }.join(line_separator)
if trailing_separator
text += line_separator
end
return text
end
# Convert our parsed record into a text record.
def to_line(details)
unless type = @record_types[details[:record_type]]
raise ArgumentError, "Invalid record type %s" % details[:record_type]
end
case type[:type]
when :text: return details[:line]
else
joinchar = type[:joiner] || type[:separator]
line = type[:fields].collect { |field|
# If the field is marked absent, use the appropriate replacement
if details[field] == :absent or details[field].nil?
if type[:optional].include?(field)
type[:absent]
else
raise ArgumentError, "Field %s is required" % field
end
else
details[field].to_s
end
}.reject { |c| c.nil?}.join(joinchar)
if regex = type[:rts]
# If they say true, then use whitespace; else, use their regex.
if regex == true
regex = /\s+$/
end
return line.sub(regex,'')
else
return line
end
end
end
# Whether to add a trailing separator to the file. Defaults to true
def trailing_separator
if defined? @trailing_separator
return @trailing_separator
else
return true
end
end
def valid_attr?(type, attr)
type = symbolize(type)
if @record_types[type] and @record_types[type][:fields].include?(symbolize(attr))
return true
else
if symbolize(attr) == :ensure
return true
else
false
end
end
end
private
# Define a new type of record.
def new_line_type(name, type, options)
@record_types ||= {}
@record_order ||= []
name = symbolize(name)
if @record_types.include?(name)
raise ArgumentError, "Line type %s is already defined" % name
end
options[:name] = name
options[:type] = type
@record_types[name] = options
@record_order << name
return options
end
end
# $Id$
|