Fold is a Unix command used for making a file with long lines more readable on a limited width terminal. Most Unix terminals have a default screen width of 80, and therefore reading files with long lines could get annoying. The fold command puts a line feed every X characters if it does not reach a new line before that point. If the -w argument is set, the fold command allows the user to set the maximum length of a line.
As a usage example, to fold a file named file.txt to have a maximum of 50 characters per line, one could run the following command:
file.txt:Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Curabitur dignissimvenenatis pede. Quisque dui dui, ultricies ut, facilisis non, pulvinar non,purus. Duis quis arcu a purus volutpat iaculis. Morbi id dui in diam ornaredictum. Praesent consectetuer vehicula ipsum. Praesent tortor massa, congue et,ornare in, posuere eget, pede. Vivamus rhoncus. Quisque lacus. In hac habitasse platea dictumst. Nullam mauristellus, sollicitudin non, semper eget, sodales non, pede. Phasellus variusullamcorper libero. Fusce ipsum lorem, iaculis nec, vulputate vitae, suscipitvel, tortor. Cras varius.Nullam fringilla pellentesque orci. Nulla eu ante pulvinar velit rhoncuslacinia. Morbi fringilla lacus quis arcu. Vestibulum sem quam, dapibus in,fringilla ut, venenatis ut, neque.
output:Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Curabitur dignissimvenenatis pede. Quisque dui dui, ultricies ut, facilisis non, pulvinar non,purus. Duis quis arcu a purus volutpat iaculis. Morbi id dui in diam ornaredictum. Praesent consectetuer vehicula ipsum. Praesent tortor massa, congue et,ornare in, posuere eget, pede. Vivamus rhoncus. Quisque lacus. In hac habitasse platea dictumst. Nullam mauristellus, sollicitudin non, semper eget, sodales non, pede. Phasellus variusullamcorper libero. Fusce ipsum lorem, iaculis nec, vulputate vitae, suscipitvel, tortor. Cras varius.Nullam fringilla pellentesque orci. Nulla eu ante pulvinar velit rhoncuslacinia. Morbi fringilla lacus quis arcu. Vestibulum sem quam, dapibus in,fringilla ut, venenatis ut, neque.
