I'm trying to move files to other directories with FileUtils.mv. I'm trying to define a variable called name_convention, which is a mix of strings, other variables and I also want to include a regexp, where I'm failing. My code so far:
#these are my other variables already declared from an array
season = array[11..13]
episode = array[15..17]
#and this is my 'name_convention' variable
name_convention = "friends" + season + episode + "bluray.mkv"
Up to here, everything is working fine. Except that between friends and season, there can be either a . or a _. For example:
friends_s01e01_bluray.mkv
friends.s01e01.bluray.mkv
I tried to use a regexp, like /(\.|-)/, but I got the error: no implicit conversion of regex into string ruby
How can I provide the two options to my name_convention variable, so that it can be applied to both filenames?
You're trying to interpolate a regex into a string, but you need to do the opposite - interpolate the strings into the regex:
season = "s01"
episode = "e01"
regex = /friends[\._]#{Regexp.escape(season)}#{Regexp.escape(episode)}.bluray.mkv/
regex.match "friends_s01e01_bluray.mkv"
# => MatchData
regex.match "friends.s01e01_bluray.mkv"
# => MatchData
regex.match "friends-s01e01_bluray.mkv"
# => nil
For this particular example (s01 and e01) you don't need the Regexp.escape but it's a good idea to include it just in case.
If you're looking for a quick and dirty sNNeNN parser, try this:
def parse_episode(str)
m = str.match(/\A(.*?)[\-\_\.]?(s\d+)(e\d+)[\-\_\.]?(.*)\z/i)
# If matched, strip out the first entry which is the complete match
m&.to_a&.drop(1)
end
Where this produces results like:
parse_episode('snowpiercer-s01e01-stream')
# => ["snowpiercer", "s01", "e01", "stream"]
parse_episode('s01')
# => nil
parse_episode('wilford')
# => nil
parse_episode('simpsons_S04E12_monorail')
# => ["simpsons", "S04", "E12", "monorail"]
parse_episode('simpsons.S04E12')
# => ["simpsons", "S04", "E12", ""]
Related
I have the next text:
My name is %{name}
how can I get name inside of %{ ... }?
I'm trying with:
/%{(.*)}/
but it takes whole %{name}, but I need just name.
When I try this expression in regex101.com, it gives me 2 cases: Full match({name}) and Group 1(name). In my ruby code it gives me Full case, but I need Group case.
What is the problem?
You can use lookaround:
(?<=%{)[^%]*(?=})
see demo.
(?<=%{) will ensure that the next part is preceded with %{
[^%]* will match avoid issue with encapsulated field
(?=}) will ensure that it's followed by a }
Don't know how you're applying that regex to the string, but .match method returns a MatchData object, from which you can extract matched groups
s = 'My name is %{name}'
regex = /%{(.*)}/
m = s.match(regex) # => #<MatchData "%{name}" 1:"name">
m[0] # => "%{name}"
m[1] # => "name"
It looks nicer with named groups
s = 'My name is %{name}'
regex = /%{(?<var>.*)}/
m = s.match(regex) # => #<MatchData "%{name}" var:"name">
m[:var] # => "name"
In Ruby, you can easily access any capture group you need with
s[/regex/, n]
where n is the ID of the capturing group. So, in your case, use
s[/%{([^}]*)}/, 1]
or
s[/%{(.*?)}/m, 1]
See the online demo
You need to make the Group 1 subpattern lazy or set to match any chars but } to get as few symbols as possible in order not to overflow to the next match.
I have some strings that look like any of these:
/challenges/:challenge_id/submissions/:id
/challenges/:challenge_id/submissions
/api/v1/submissions/:id
/submissions
The strings starting with ':' and ended by a '/' or a blank line are Rails route params. ie: 'challenge_id' and ':id'
I'd like to do 2 things with this string
extract the route param variables into a ruby array for later use
replace those param variables by '1'
So output for the first example:
arr = [':challenge_id',':id']
new string = '/challenges/1/submissions/1'
I've tried this, but it is matching everything
/[:[a-z*]]/
I'm testing in http://rubular.com/ as I need this to run in Ruby code.
arr = []
"/challenges/:challenge_id/submissions/:id".gsub(/:[^\/]+/){|s| arr.push(s); "1"}
# => "/challenges/1/submissions/1"
arr
# => [":challenge_id", ":id"]
If you want to match params that may have capital letters in them, then you can use \w shorthand:
:\w+
This will match all params including the ones with capital letters.
# For example:
/challenges/:Challenge_id/submissions/:ID
Ruby code:
string = "/challenges/:challenge_id/submissions/:id"
# To get a matching params array
string.scan(/:\w+/) # => [":challenge_id", ":id"]
# To replace them with "1"s
string.gsub(/:\w+/, '1') # => "/challenges/1/submissions/1"
The regex should be this:
(:[a-z]*)
() is for the capture group.
"*" should be outside the character class.
To improve your current regex, you could do this:
(\/:[a-z]+)
Add a forward slashes "/", so not to match ":" in the middle of the param variables and change the "*" operator to "+", so not to match ":" alone.
I am trying to use gsub or sub on a regex passed through terminal to ARGV[].
Query in terminal: $ruby script.rb input.json "\[\{\"src\"\:\"
Input file first 2 lines:
[{
"src":"http://something.com",
"label":"FOO.jpg","name":"FOO",
"srcName":"FOO.jpg"
}]
[{
"src":"http://something123.com",
"label":"FOO123.jpg",
"name":"FOO123",
"srcName":"FOO123.jpg"
}]
script.rb:
dir = File.dirname(ARGV[0])
output = File.new(dir + "/output_" + Time.now.strftime("%H_%M_%S") + ".json", "w")
open(ARGV[0]).each do |x|
x = x.sub(ARGV[1]),'')
output.puts(x) if !x.nil?
end
output.close
This is very basic stuff really, but I am not quite sure on how to do this. I tried:
Regexp.escape with this pattern: [{"src":".
Escaping the characters and not escaping.
Wrapping the pattern between quotes and not wrapping.
Meditate on this:
I wrote a little script containing:
puts ARGV[0].class
puts ARGV[1].class
and saved it to disk, then ran it using:
ruby ~/Desktop/tests/test.rb foo /abc/
which returned:
String
String
The documentation says:
The pattern is typically a Regexp; if given as a String, any regular expression metacharacters it contains will be interpreted literally, e.g. '\d' will match a backlash followed by ‘d’, instead of a digit.
That means that the regular expression, though it appears to be a regex, it isn't, it's a string because ARGV only can return strings because the command-line can only contain strings.
When we pass a string into sub, Ruby recognizes it's not a regular expression, so it treats it as a literal string. Here's the difference in action:
'foo'.sub('/o/', '') # => "foo"
'foo'.sub(/o/, '') # => "fo"
The first can't find "/o/" in "foo" so nothing changes. It can find /o/ though and returns the result after replacing the two "o".
Another way of looking at it is:
'foo'.match('/o/') # => nil
'foo'.match(/o/) # => #<MatchData "o">
where match finds nothing for the string but can find a hit for /o/.
And all that leads to what's happening in your code. Because sub is being passed a string, it's trying to do a literal match for the regex, and won't be able to find it. You need to change the code to:
sub(Regexp.new(ARGV[1]), '')
but that's not all that has to change. Regexp.new(...) will convert what's passed in into a regular expression, but if you're passing in '/o/' the resulting regular expression will be:
Regexp.new('/o/') # => /\/o\//
which is probably not what you want:
'foo'.match(/\/o\//) # => nil
Instead you want:
Regexp.new('o') # => /o/
'foo'.match(/o/) # => #<MatchData "o">
So, besides changing your code, you'll need to make sure that what you pass in is a valid expression, minus any leading and trailing /.
Based on this answer in the thread Convert a string to regular expression ruby, you should use
x = x.sub(/#{ARGV[1]}/,'')
I tested it with this file (test.rb):
puts "You should not see any number [0123456789].".gsub(/#{ARGV[0]}/,'')
I called the file like so:
ruby test.rb "\d+"
# => You should not see any number [].
Is there a way to do this?
I have an array:
["file_1.jar", "file_2.jar","file_3.pom"]
And I want to keep only "file_3.pom", what I want to do is something like this:
array.drop_while{|f| /.pom/.match(f)}
But This way I keep everything in array but "file_3.pom" is there a way to do something like "not_match"?
I found these:
f !~ /.pom/ # => leaves all elements in array
OR
f !~ /*.pom/ # => leaves all elements in array
But none of those returns what I expect.
How about select?
selected = array.select { |f| /.pom/.match(f) }
p selected
# => ["file_3.pom"]
Hope that helps!
In your case you can use the Enumerable#grep method to get an array of the elements that matches a pattern:
["file_1.jar", "file_2.jar", "file_3.pom"].grep(/\.pom\z/)
# => ["file_3.pom"]
As you can see I've also slightly modified your regular expression to actually match only strings that ends with .pom:
\. matches a literal dot, without the \ it matches any character
\z anchor the pattern to the end of the string, without it the pattern would match .pom everywhere in the string.
Since you are searching for a literal string you can also avoid regular expression altogether, for example using the methods String#end_with? and Array#select:
["file_1.jar", "file_2.jar", "file_3.pom"].select { |s| s.end_with?('.pom') }
# => ["file_3.pom"]
If you whant to keep only Strings witch responds on regexp so you can use Ruby method keep_if.
But this methods "destroy" main Array.
a = ["file_1.jar", "file_2.jar","file_3.pom"]
a.keep_if{|file_name| /.pom/.match(file_name)}
p a
# => ["file_3.pom"]
I am having a ruby script file for patter match. my input string look like below
this.plugin = document.getElementById("pluginPlayer");
my regex look like
regxPlayerVariable = '(.*?)=.*?document\.getElementById\("#{Regexp.escape(pluginPlayeVariable)}"\)'
here pluginPlayeVariable is a variable but its not macthing with input string.
if i change my rege and replace variable with its value it's work fine but i can not do that as it's a run time value which change accordingly.
i also tried some more regex mention below
regxPlayerVariable = '(.*?)=.*?document\.getElementById\("#{pluginPlayeVariable}"\)'
so how can i solve this issue?
First of all, regxPlayerVariable is not a Regexp, it's a String. And the reason why your interpolation does not work is because you are using single quotes. Look:
foo = "bar"
puts '#{foo}' # => #{foo}
puts "#{foo}" # => bar
puts %q{#{foo}} # => #{foo}
puts %Q{#{foo}} # => bar
puts %{#{foo}} # => bar
puts /#{foo}/ # => (?-mix:bar)
puts %r{#{foo}} # => (?-mix:bar)
Only the last two are actually regular expressions, but here you can see which quoting expressions do interpolation, and which don't.