re = /^f(([ ]\d{1,2}(\/{0,2}\d{0,1})\/{0,1}){0,3})$/m
str = 'f 1 2 3
f 1/ 2/ 3/
f 1// 2// 3//
f 1/1 2/2 3/3
f 1/1/ 2/2/ 3/3/
f 1//1 2//2 3//3
f /1/ /2/ /3/
f 1/1/1 2/2/2 3//3
f 1/1 2/2 3/3 4/4
^f(([ ]\\d{1,2}(\\/{0,2}\\d{0,1})\\/{0,1}){0,3})$
[18:08, 20/11/2019] Jose Luis Uni
^f(([ ]\\d+(\\/{0,2}\\d+))+)$
[18:30, 20/11/2019] Jose Luis Uni:
^f(([ ](\\d+)(\\/{0,2}\\d+))+)$
^f(([ ](\\d+)(\\/{0,2}\\d*))+)$
'
# 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