Frequently Asked Question

How do I format text neatly with fold, fmt, and column?

fold wraps long lines to a fixed width. fold -w 80 breaks each line at 80 characters; fold -s -w 80 does the same but breaks at spaces rather than mid-word. It is mechanical: it counts characters and inserts newlines, with no understanding of paragraphs. fmt is smarter, it reflows text paragraph by paragraph, joining short lines and breaking long ones to roughly fit a width (75 characters by default). It treats blank lines as paragraph boundaries, which makes it suitable for prose but not for code.

column does something different: it formats tabular input into aligned columns. Given a tab-separated file, column -t produces a tidy table with auto-sized columns; column -t -s, does the same for comma-separated input. Piped through after a cut or awk it turns ragged output into something readable. Together these three cover most of the layout problems that arise when piping text to a terminal: fold for raw width, fmt for prose, column for tables.