How to Use the Ruby pack Method

09/22/2021

Contents

In this article, you will learn how to use the Ruby pack method.

Using the pack method

The pack method in Ruby is used to convert data from one format to another. It takes a series of arguments that define how the data should be packed and returns a binary string.

Here is how to use the pack method:

  1. Choose a format string that defines how the data should be packed. The format string is a series of codes that indicate the type of data and how it should be formatted.

    For example, the code “A4” indicates a string of 4 characters, while “I” indicates a 32-bit integer.

  2. Pass the data you want to pack as arguments to the pack method. The data can be passed as individual arguments or as an array.

    For example, to pack the string “hello” and the integer 42, you can use the following code:

    data = ["hello", 42]
packed_data = data.pack("A5I")

    In this example, the format string “A5I” indicates that the first argument should be a string of 5 characters, and the second argument should be a 32-bit integer.

  3. The pack method returns a binary string that represents the packed data. This binary string can be written to a file or transmitted over a network.

    For example, to write the packed data to a file, you can use the following code:

    File.open("packed_data.bin", "wb") do |f|
  f.write(packed_data)
end

    In this example, the “wb” argument to the File.open method indicates that the file should be opened in binary mode for writing.

#Ruby