Writing files in a specific encoding in Ruby

Recently, I was trying to create PDF files of barcodes. I was using barby gem for generating barcodes. When I tried to write the generated PDF, I found that the PDF string was in ASCII-8BIT encoding while my console was in UTF-8 which was causing Ruby to attempt writing in UTF-8 encoding causing errors. So, to write to the file in ASCII-8BIT, I had to specify that while opening the file. I achieved that using the following and I could write to the file correctly.

f = File.open("test.pdf", "w:ASCII-8BIT")

f.write the_pdf_string

f.close