fold —
fold long lines for finite width output device
  
    | fold | [ -bs] [-wwidth] [file ...] | 
fold is a filter which folds the contents of the
  specified files, or the standard input if no files are specified, breaking the
  lines to have a maximum of 80 characters.
The options are as follows:
  - -b
- Count width in bytes rather than column
    positions.
- -s
- Fold line after the last blank character within the first
      width column positions (or bytes). If a blank
      character does not exist within the width, then a longer line will still
      be split at the width.
- -wwidth
- Specifies width to use as a line width, instead of
      the default 80 characters.
Thefold utility exits 0 on success,
  and >0 if an error occurs.
The fold utility conforms to IEEE Std
  1003.1-2008 (“POSIX.1”).
The fold utility appeared in
  1BSD.
If underlining is present it may be messed up by folding.
Width should be a multiple of 8 if tabs are
    present, or the tabs should be expanded using
    expand(1) before using
    fold.