fmt - simple text formatter
fmt [goal [maximum]] [file ...]
The fmt(1) utility is a simple text formatter that reads the concatenation of input files (or standard input if none are given) and produces on standard output a version of its input with lines as close to the goal length as possible without exceeding the maximum. The goal length defaults to 65 and the maximum to 75. The spacing at the beginning of the input lines is preserved in the output, as are blank lines and interword spacing.
The fmt(1) utility is meant to format mail messages prior to sending, but can also be useful for other simple tasks. For instance, within visual mode of the vi(1) editor, you can reformat a paragraph and make the lines even by using the command:
!}fmt
fold(1)
mailx(1)