- The puts Statement
- A Programmer's Best Friend
- Working with Files in Ruby - Techotopia
- How to Create Temporary Files in Ruby
While load is handy when you're playing around with command line scripts because it saves you from quitting IRB to refresh your changes, you should stick with require if you use this functionality in your own scripts.
That's because require makes sure you've only loaded the file once while, with load you might have accidental double-or-triple loads if multiple files require each other. Another thing that you'll probably want to do at some point is to access the variables that were passed to your script from the command line.
For instance, if you ran:.
The puts Statement
You've passed in "howdy" and "everyone". You access these inputs by digging into a special constant which is a variable you shouldn't try to change called ARGV. ARGV is simply an array that contains all your command line arguments:. As you can see in the last example above, you can only pass in command line arguments from the actual command line not within IRB. There is a trick you can sometimes use to check whether your script is being run from the command line or as part of a larger program instead.
A Programmer's Best Friend
You might do so if you want to puts some stuff only if it's called from the CLI to debug it maybe. Despite learning all those options, there's one which is particularly easy. Most modern text editors have the options to "build" or run your code right in the editor.
The specifics of how to do so are just a Google search away for your particular editor. There are a number of different ways to run your Ruby scripts and it's good to give each of them a try before you settle on one as your "go-to". A little bit of investment in learning these things can quickly add up to minutes and even hours of time. There are additional resources for this lesson. Check them out! Viking Code School Prep. X Welcome to the Basic Prep!
- Talkshow (German Edition).
- First Ruby Program: Ruby Study Notes - Best Ruby Guide, Ruby Tutorial;
- A Brief Biography of Beethoven!
Ruby Love. Running a Script You're probably tired of running your methods in IRB if that's what you're still doing so it's time to learn how to break them out into a separate script file which you can then run in its entirety from the command line. This takes 2 steps: Use the chmod command to declare the file executable. Share this post! This file gets deleted automatically.
How can you do this in Ruby? Like this : require 'tempfile' Tempfile. This is built into Ruby so you don't have to install any gems. That's simple enough, but you may still have questions. Like : When is the file deleted exactly?
- Chinese Takeaway!
- Vintage Jeweled and Fancy Crochet Collar Patterns – Perfect Crocheted Gifts.
- My First Ruby Program.
- How to Create Temporary Files in Ruby.
Why can't I read back from my temp file? Are tempfiles guaranteed to be unique? You'll notice that Tempfile has two methods for creating files. One is new , and the other is create. What's the difference?
Working with Files in Ruby - Techotopia
I don't think that really matters, because Tempfile delegates to File. The real difference is that create accepts a block. But new doesn't. Try this : Tempfile. This brings up the following question When is A TempFile Deleted? Automatic deleting works when : Your programs ends Your file gets garbage collected from memory The later can only happen if you aren't holding any references to the file.
How to Create Temporary Files in Ruby
Like a variable. If you try to read back from one of your temporary files you'll get an empty string. Example : Tempfile. It turns out that Files are IO objects. So if you want to read, you have to rewind this pointer. Like this : Tempfile. But can there ever be a duplicated name? The documentation says this : "Tempfile's filename picking method is both thread-safe and inter-process-safe: it guarantees that no other threads or processes will pick the same filename.
It's also good to know that you can set a prefix for your files.