Variable: eshell-variable-name-regexp
eshell-variable-name-regexp is a customizable variable defined in
esh-var.el.gz.
Value
"[A-Za-z0-9_-]+"
Documentation
A regexp identifying what constitutes a variable name reference.
Note that this only applies for $NAME. If the syntax $<NAME> is
used, then NAME can contain any character, including angle brackets,
if they are quoted with a backslash.
Source Code
;; Defined in /usr/src/emacs/lisp/eshell/esh-var.el.gz
(defcustom eshell-variable-name-regexp "[A-Za-z0-9_-]+"
"A regexp identifying what constitutes a variable name reference.
Note that this only applies for `$NAME'. If the syntax `$<NAME>' is
used, then NAME can contain any character, including angle brackets,
if they are quoted with a backslash."
:type 'regexp)