I'm looking for a step to step tutorial to make an app, not so complex in Ruby, so students can do it. By now, i have only medium-big examples that i have developed for companies some years ago,but they require extra knowledge as i used diff frameworks and libraries and i want something that can be done only with the ruby interpreter itself.
A well commented app will be good as well as i can make some step-to-step guide based on that, and yea maybe I can do one but the thing is that im running out of time, and i haven't used ruby in like 1.5-2years, so as i said im looking for something not so complex and not so big, 200 , 300, 400, or 500 lines of code is ok
Could be anything, like administration or managing purpose like idk, a script that generates word documents for certain department. A script that reads a .txt or .doc and do something with that, idk.
Thanks in advance!
It's not an app really, but it's smallish, it's Ruby, it's sort of a game, and it's fun. http://github.com/ryanb/ruby-warrior
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I like reading the PoC||GTFO issues and one thing I found remarkable when I first discovered it, was the "polyglot" nature of their PDF files.
Let met explain: when you consider for example their 8th issue, you may unzip files from it; execute the encryption they are talking about by running it as a script and even better(worse?) with their 9th issue you can even play it as a music file!
I'm currently in the process of writing small scripts every week and writing each time a little one page PDF in LaTeX to explain the said scripts. So I would really enjoy being able to create the same kind of PDF files. Sadly they explained (partly) in their first issue how to include zip files, but they did so through three small sketches of cmd lines without actual explanations.
So my question is basically :
how can one create such a polyglot PDF file containing stuff like a zip as well as being a shell script which may be run using arguments just like normal scripts?
I'm asking here about the process of creation, not just an explanation of how this is possible. The ideal way for me would that there are already some scripts or programs allowing to create easily such PDF files.
I've tried to search the net for the keywords "polyglot files" and others of the kind and wasn't able to find any useful matches. Maybe this process has another name?
I've already read the presentation by Julia Wolf which explains how things works, but I sadly haven't had time to apply the knowledge there to real world, because I'm sadly not used to play with file headers and the way a PDF is constructed.
EDIT:
Okay, I've read more and found the 7th edition of PoC||GTFO to be really informative concerning this subject. I may end up being able to create my own scripts to do such polyglot PDF files if I have some more time to consider it.
I played around with polyglots myself after attending Ange's talks and also talking to him in person. You really need to understand the file formats to be able to nest them into each other.
However, long story short, here are some links I found extremely useful for creating polyglots:
Some older Google Code Trunk
PoC of the polyglot stuff
Especially the second link (to github) will help you creating polyglots, but also understanding how they are working and how they are implemented. Since it is mostly Python stuff and very well / clean written, it is very useful and easy to follow.
I feel dissecting some file formats would be a good place to start. You can find many file format specifications for different file types through Google, but they can be a tough read and will likely take you some time to translate into whatever language you are using.
PDF: https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf
ELF: https://www.cs.cmu.edu/afs/cs/academic/class/15213-s00/doc/elf.pdf
ZIP: http://kat.sdf.org/zip_file_format.txt
The language(s) you select will need a way to read and write raw bytes (not just ascii alphanumeric), so perhaps C would be good for more direct access to memory. Some Python tricks could help with open sourcing the scripts easily.
To dissect the files, you may want to build a tool kinda like https://github.com/kvesel/zipbrk/ to take them apart, then put them all back together in a polyglot format. For example, zip does not require the section headers to be at the start (or even contiguous for that matter), and PDF magic number can appear in multiple places within the file as well. I also believe I recall a polyglot tool being included in one of the PoC||GTFO publishings (maybe issue 8 or 2??) as a polyglot in the pdf file.
Don't forget the hackers bible! :)
https://nostarch.com/gtfo
What tools or steps would you recommend to someone who is brand new to a project and they are trying to get acclimated to a Ruby on Rails codebase that has no testing?
I am considering something like: https://codeclimate.com/ to help run some analysis on the code but I wanted other suggestions.
Thanks!
I use the command line tool wc to find where the code hotspots are. Running wc ./app/models/**/*.rb | sort -nr on my Mac gives me a pretty good idea of where the code is sitting. You can replace models with controllers or any other directory to find the details there.
Once I have a good idea of where things are, it's easier to find the larger and more complex areas of code. A brief description of the project and a run of wc should give you a pretty good idea of which data models and controllers are the most complex, and give you an idea of where to go for further investigation.
If the project is well tested I would definitely take the time to read through the spec headings. I'd take time to read through the implementation details of specs that interest me.
The Ruby Rogues podcast has a pretty good episode about code reading that you may find helpful: http://rubyrogues.com/031-rr-code-reading/
I'm hoping this is a will tested project... If it is, I always read through the tests first as they give you an understanding of what the expectations of each piece of code is. This its by far the best method that has worked for me.
I have users that have authenticated with a social media site. Now based on their last X (let's say 200) posts, I want to map how much that content matches up with a finite list of keywords.
What would be the best way to do this to capture associated words/concepts (maybe that's too difficult) or just get a score of how much, say, my tweet history maps to 'Walrus' or 'banana'?
Would a naive Bayes work here to separate into 'matches' and 'no match'?
In Python I would say NLTK can easily do it. In Ruby maybe gem called lda-ruby will help you. Whole LDA concept is well explained here - look at Sarah Palin's email for example. There's even the example of an app (not entirely in Ruby, but still) which did that -> github.com/echen/sarah-palin-lda
Or maybe I just say stupid things and that can't help you at all. I'm not an expert ;)
A simple bayes would work in this case, it is highly used to detect if emails are spam or not so for a simple keyword matching it should work pretty well.
For this problem you could also apply a recommendation system where you look for the top recommended keyword for a user (or for a post).
There are a ton of ways for doing this. I would recommend you to read Programming Collective Intelligence. It is explained using python but since you know ruby there should be not problem to understand the code.
What's a good way to parse HTML in AppleScript?
I haven't dabbled in AppleScript in quite some time, and even when I did it was very minimal and uninvolved, so I don't really think naturally in the language quite yet. But I need to do some string manipulation and parse some HTML (basically some simple screen scraping).
Naturally, I'd like to avoid common pitfalls of HTML parsing. However, this is a temporary script and doesn't need to be particularly robust or supportable. I really just need to scrape specific substrings (from a known starting substring to the next known character) into a file.
I've done plenty of string manipulation in C# and similar languages, but AppleScript is an interesting change of pace to say the least. Can somebody point me to some good resources (Google searches on this subject seem to have a high noise-to-signal ratio), or help me out with some sample code snippets?
The ultimate goal of what I'm doing is to take a pre-determined list of pages, open each one in Safari (I'm doing everything through tell application "Safari"), parse out links which fit a certain pattern, and store all of those links in a file. Then go through that file, open each of those links, parse out more links which fit another pattern, and store all of those links in a file.
(The site is actually owned by someone we're working with, so don't worry about me violating any terms of service or anything like that. But for reasons outside the scope of this question, I'm doing some page scraping in AppleScript.)
I can't say enough good things about Matt Neuburg's AppleScript: the Definitive Guide. Without a doubt the most complete documentation of AppleScript ever done. Matt's also one of my favorite tech writers.
I would also check out this article. It contains a tutorial on how to do this; the example provided there parses HTML data from only one source, but I think it's worth looking at.
I'm building a site that allows users to make sense of a debate by graphically representing arguments for and against a particular issue. (Wrangl)
I'd like to categorise these debates so they are more easily found and connected. I don't want to irritate the person creating the debate by asking them to add tags and categories before they see any benefit, so I'm looking at a way of automatically extracting keywords.
What's a good approach for taking the debate's title and description (and possibly the content of the arguments themselves once there are some) to pull out, say, ten strong keywords that could be used as metadata to connect similar debates together, or even as the content of the "meta" keywords tag in the head of the HTML page where the debate is viewable. Eg. Datamapper vs ActiveRecord
The site is coded in Ruby with Sinatra, using DataMapper for data storage. I'm ideally looking for something which will work on Heroku (I don't have a way of writing files to disk dynamically), and I'd consider a web service, an API or ideally a Ruby gem.
Maybe you can use TextAnalyzer.
I understand that you're wanting to find an easy way of achieving this, I've recently dived into the world of NLP (Natural Language Processing) and Text-mining and its a daunting process of which most went far above my head.
Although i managed to code some functionality that resembles what you're looking for, though I did it in PHP. What i would suggest, that if you want it tailored to your project (Wrangl) then do it yourself.
Using the Porter stemming algorithm which I'm sure there will be Ruby code for.
Ruby Porter stemmer
You can try the salsaAPI to automatically extract keywords and categorize the debates!