How to wrap each input line to fit in specified width in linux

1. fold name

fold – wrap each input line to fit in specified width

2. Fold synopsis in linux

fold [OPTION]... [FILE]... 

3. Fold frequently used options

-w, --width=WIDTH
      use WIDTH columns instead of 80 

4. Examples

fold file to width of 3 characters:

fold -3 commands.txt