FOLD (1) | General commands | Unix Manual Pages | :man▋
fold - "fold long lines for finite width output device"
fold [-bs] [-w width] 
The fold utility 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 columns.
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). |
|-w width |
| || Specify a line width to use instead of the default 80 columns. Width should be a multiple of 8 if tabs are present, or the tabs should be expanded using expand(1) before using fold. |
The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of fold as described in environ(7).