Read and Write Files in Ruby

Writing a File in Ruby

Ruby provides several methods and approaches to do a write operation on a file; all actions performed on any file system will be done with the Ruby File class. The file class system allows the developer to perform writing work on the file system by using various methods such as open, new, and write. It allows us to write either in append (add new contents on the existing content with newlines) mode or on normal write (, in Ruby, the shortest way to write the content will be done with the method), write (here write method will work in a variety of modes such as append and write).

Methods for Writing a File in Ruby

In Ruby, we have several techniques and methods for writing the contents of a file, such as new, open in append mode and write mode, and direct-write (write is also accessible in various modes such as append mode and write mode). Let us go over all of the different ways to write on any file.

Using the ‘new’ Keyword

• First, a file is created called txt, and some content is inserted into it
   
• We called a new function with two arguments, the first being the name and location of the file to be read and the second being the mode in which we are opening the file (in this example, we are opening the file in the write(+r) mode)
   
• Use the if statement to check whether the file is empty or not
   
• Finally, using the method syswrite, which will either write the content or just remove the existing contents and replace them with the contents supplied into the function. The overall length of the letter on the file will be returned by this function. The example shows that it yields 32
   
• We can view the contents of the file test.txt both before and after the code block is executed
   

Code:

• Ruby

Ruby

temporayFile = File.new("test.txt", "r+")
if temporayFile
data = temporayFile.syswrite("Welcome to Coding Ninjas Studio!")
puts data
else
puts "Not able to access the file"
end

You can also try this code with Online Ruby Compiler

Run Code

Output:

Using the Open in Append Mode

Append mode means that each time we run the code, it will add new content to a new line. When we need older and new stuff on the file system, we do this process. The following example can be broken down into two steps.

• In the first stage, we open the file test.txt and walk through each line, adding new text on each new line
   
• In the second step, we open the file in read mode and print the entire contents
   

Code:

• Ruby

Ruby

#Here, the argument "a" indicates we are opening the file in append mode.
File.open("test.txt","a") do |line|
line.puts "\r" + "Welcome again in file system"
end
File.open("test.txt").each do |line|
puts line
end

You can also try this code with Online Ruby Compiler

Run Code

Output:

Using the write Method Directly

In the below example, we are not opening the file. We are directly writing content on the file with the help of the method write. We are performing two main operations, which can be explained in two steps.

• In the first stage, we write the content by supplying two arguments to the method write (file name and contents). We can additionally pass the writing mode, such as append or write (in the same way that the open method does)
   
• Second, we read the file content that was added in the previous step
   

Code:

• Ruby

Ruby

File.write('test.txt', 'This we are adding without opening the file')
File.open("test.txt").each do |line|
puts line
end

You can also try this code with Online Ruby Compiler

Run Code

Output:

Frequently Asked Questions

What is Ruby Module?

A Ruby module is a group of methods and constants. A module method can be either an instance method or a module method. They are comparable to classes in that they contain a set of methods, class definitions, constants, and other modules. They are defined in the same way as classes are.

What is Ruby Programming Language?

Ruby is an open-source, dynamic, reflective, general-purpose programming language with a focus on simplicity and productivity. Ruby combines Perl, Smalltalk, Eiffel, Ada, and Lisp capabilities. Ruby was created to be a new language that balances the features of Imperative languages.

What is Ruby Exception?

A Ruby exception is a class instance or descendant of the class Exception. When something goes wrong, the Ruby program exhibits abnormal behavior. By default, a Ruby program will terminate whenever an exception is thrown.

Conclusion

In this blog, we learned about reading and writing on the file system and saw several methods to read and write files in Ruby programming language. We learned how to use the methods through the usage of certain essential examples.

To better understand the topic, you can refer to What is Ruby, Methods in Ruby, and Ruby is an object-oriented language.

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