Break the lines of the named files
so that they are no wider than the specified width. fold
breaks lines exactly at the specified width, even in the middle of a word.
The line width specifies bytes, not characters. Solaris only.
Break lines after the last whitespace character within the first width
characters. Solaris only.
Create lines having width n
(default is 80). (Can also be invoked as
for compatibility with BSD.)