Dealing with Trailing Whitespace in Emacs
Trailing whitespace
The term refers to unnecessary spaces at the end of a line and also to empty lines at the end of a buffer
How can I show trailing whitespace?
You can show trailing whitespace at the end of a line by setting this variable:
show-trailing-whitespace t
Note: One can change the face of trailing whitespace when this variable is activated:
M-x customize-face trailing-whitespace
Note: If point is at the end of the line this feature does not apply as it would be too unseemly.
To show empty lines at the end of the buffer:
(setq-default indicate-empty-lines t)
The empty lines are indicated in the fringe.
How to deal with trailing whitespace?
Non-aggressive approach
M-x delete-trailing-whitespace deletes all trailing whitespace
This command deletes all extra spaces at the end of each line in the buffer and all empty lines at the end of the buffer.
(global-set-key (kbd "C-c w") 'delete-trailing-whitespace)
More aggressive approach
M-x whitespace-cleanup
More complex solutions
whitespace-mode lets you visualise many kinds of whitespace in the buffer
You can customize your whitespace style by setting this variable:
whitespace-style
Note: One would not require this mode and show-trailing-whitespace
Miscellaneous
M-SPC – delete extra spaces between words
delete-blank-lines – delete extra blank lines between paragraphs
next-line-add-newlines – prevents adding newlines at end of buffer with arrow key