Hello,

In sh and Bash, the characters !%^~:.,= and are not valid in variable or
function names.

Assigning them the "_" syntax causes Emacs to treat them as word
constituents, disrupting navigation and completion
(e.g. dabbrev-expand, forward-word, etc.).

The attached patch updates the syntax table in sh-mode to mark
these characters as punctuation, correcting the issue.

--
James Cherti
GitHub: https://github.com/jamescherti
Website: https://www.jamescherti.com/