Ruby检查正则表达式

Question

New to ruby here,

I'm wondering how to check for regular expressions in Ruby. Read a lot of the documentations but it was quite confusing.

I need to check files with lines in this format:

id: 123456 synset: word1,word2,etc

The number of digits of the integer doesn't matter, how many words are in synset doesn't matter neither.

Am I suppose to use Regexp ? Can someone give me an example?

Answer 1

Regex would be handy here:

str = 'id: 123456 synset: word1,word2,etc'
m = str.match(/\Aid: (\d+) synset: (.+)\z/)
id, synset = m.captures
id
 => "123456" 
synset
 => "word1,word2,etc" 

Or you could split the string into an array:

arr = str.split
_, id, _, synset = arr
id
 => "123456" 
synset
 => "word1,word2,etc" 

Answer 2

./file1.rb:

id: 123456 synset: word1,word2
id: 123456 synset: word1,word2
a;sdlkfjasdlkfj
id: 123456 synset: word1,word2

./file2.rb

file = File.new('./file1.rb','r+')
p file.grep(/^id: \d+ synset: (\w+,?)+$/)
#[
# id: 123456 synset: word1,word2,
# id: 123456 synset: word1,word2,
# id: 123456 synset: word1,word2"
#]

Uses Enumerable#grep to return an array of only the lines which match the regex.