re = /(?<!foo.{0,1000})bar(?!.*foo)/m
str = 'bar //true
,bar, //true
,,bar,, //true
barbar //true
,bar,bar, //true
,,bar,,bar,, //true
barbarbar //true
,bar,bar,bar, //true
,,bar,,bar,,bar,, //true
foo //false
,foo, //false
,,foo,, //false
foobar //false
,foo,bar, //false
,,foo,,bar,, //false
barfoo //false
,bar,foo, //false
,,bar,,foo,, //false
foofoo //false
,foo,foo, //false
,,foo,,foo,, //false
foobarbar //false
,foo,bar,bar, //false
,,foo,,bar,,bar,, //false
barfoobar //false
,bar,foo,bar, //false
,,bar,,foo,,bar,, //false
barbarfoo //false
,bar,bar,foo, //false
,,bar,,bar,,foo,, //false
barfoofoo //false
,bar,foo,foo, //false
,,bar,,foo,,foo,, //false
foobarfoo //false
,foo,bar,foo, //false
,,foo,,bar,,foo,, //false
foofoobar //false
,foo,foo,bar, //false
,,foo,,foo,,bar,, //false
foofoofoo //false
,foo,foo,foo, //false
,,foo,,foo,,foo,, //false'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html