Class: Grepper
- Inherits:
-
Object
- Object
- Grepper
- Defined in:
- lib/grepper.rb,
lib/grepper/formatter.rb
Overview
Grepper – simple way to grep through files and save results
Description
The Grepper class greps through files, and returns a result set of Grepper::Result objects. Each Result object represents the matches found in a single file. The Result contains a set of Grepper::Match objects. Each Match object represents a line (the line that matched) and before- and after-context arrays. If no before or after lines were requested, those context values will be nil.
To use, you prepare a Grepper object; call run
on it; and walk through the result set. This distribution comes with the Grepper::Formatter class, which is built on top of Grepper and provides fairly canonical-looking output by walking through Grepper objects. (See lib/formatter.rb
.) Meanwhile, here are the details.
Preparing a Grepper object
You instantiate Grepper, and provide it with:
-
a pattern, in the form of a regular expression
-
zero or more options, as an array
-
an array of filenames
Setting the grepper’s pattern
To specify a pattern for the Grepper object:
grepper.pattern = /abc/
Setting the grepper’s file list
grepper.files = ["file1.txt", "file2.txt"]
grepper.files = Dir["grep_me/*.txt"]
Options
To set options, you provide an array of strings. For example, for a reverse grep with two lines of after-context you would do:
grepper. = %w{ v A2 }
Available options are:
-
o
– store only the part of the line that matched the pattern -
v
– negate the sense of the match -
w
– count only complete-word matches -
An
– provide n lines of after-context -
Bn
– provide b lines of before-context
Generating the result set
To generate the result set, you call run
.
grepper.run
Now you can access grepper.results, and walk through all the matches.
Walking through the result set and match set
Given a Grepper
object grepper
, the result set will be at grepper.results
. It will iterate per entry, yielding the filename and the corresponding set of matches.
grepper.results.each do |filename, matches|
...
end
For each match set, you can iterate like this:
matches.each do |lineno, before, line, after|
...
end
If you want to walk through either set and just get the objects, not broken out into their properties, you can do:
grepper.results.each_result do |result|
and
matches.each_match do |match|
Version
0.9.3, January 13, 2009
Author
David A. Black ([email protected])
Copyright and license
Copyright © 2008-2009, Ruby Power and Light, LLC
Released under the Ruby license. No warranty of any kind. Use entirely at your own risk.
Defined Under Namespace
Modules: MatchesExtension, ResultsExtension Classes: Formatter, Match, Result
Constant Summary collapse
- VERSION =
'0.9.3'
Instance Attribute Summary collapse
-
#files ⇒ Object
Returns the value of attribute files.
-
#options ⇒ Object
Returns the value of attribute options.
-
#pattern ⇒ Object
Returns the value of attribute pattern.
-
#results ⇒ Object
readonly
Returns the value of attribute results.
Instance Method Summary collapse
-
#initialize ⇒ Grepper
constructor
A new instance of Grepper.
-
#run ⇒ Object
Generate the result set.
Constructor Details
#initialize ⇒ Grepper
Returns a new instance of Grepper.
109 110 111 112 113 114 |
# File 'lib/grepper.rb', line 109 def initialize @files = [] @options = [] @results = [].extend(ResultsExtension) @negate = false end |
Instance Attribute Details
#files ⇒ Object
Returns the value of attribute files.
106 107 108 |
# File 'lib/grepper.rb', line 106 def files @files end |
#options ⇒ Object
Returns the value of attribute options.
106 107 108 |
# File 'lib/grepper.rb', line 106 def @options end |
#pattern ⇒ Object
Returns the value of attribute pattern.
106 107 108 |
# File 'lib/grepper.rb', line 106 def pattern @pattern end |
#results ⇒ Object (readonly)
Returns the value of attribute results.
107 108 109 |
# File 'lib/grepper.rb', line 107 def results @results end |
Instance Method Details
#run ⇒ Object
Generate the result set.
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 |
# File 'lib/grepper.rb', line 162 def run massage_pattern @negate = true if .include?('v') after_count = $1.to_i if .find {|o| /A(\d+)/.match(o) } before_count = $1.to_i if .find {|o| /B(\d+)/.match(o) } if .find {|o| /C(\d+)/.match(o) } after_count ||= $1.to_i before_count ||= $1.to_i end files.each do |file| result = Result.new(file) results << result buffer = [] File.open(file) do |fh| i = 0 while line = fh.gets i += 1 if matched = match_for(line) match = Match.new(matched) match.lineno = i if after_count match.after = get_after_context(fh, after_count) i += (match.after || []).size end if before_count match.before = buffer.empty? ? nil : buffer buffer = [] end result.matches << match else if before_count buffer << line buffer.shift if buffer.size > before_count end end end end end end |