Variable: eshell-number-regexp
eshell-number-regexp is a variable defined in esh-util.el.gz.
Value
"-?\\(?:[[:digit:]]+\\(?:\\.[[:digit:]]*\\)?\\|[[:digit:]]*\\.[[:digit:]]+\\)\\(?:[Ee]\\(?:\\+INF\\|\\+NaN\\|[+-]?[[:digit:]]+\\)\\)?"
Documentation
Regular expression used to match numeric arguments.
If eshell-convert-numeric-arguments is non-nil, and an argument
matches this regexp, it will be converted to a Lisp number, using the
function string-to-number.
Source Code
;; Defined in /usr/src/emacs/lisp/eshell/esh-util.el.gz
;;; Internal Variables:
(defvar eshell-number-regexp
(rx (? "-")
(or (seq (+ digit) (? "." (* digit)))
(seq (* digit) "." (+ digit)))
;; Optional exponent
(? (or "e" "E")
(or "+INF" "+NaN"
(seq (? (or "+" "-")) (+ digit)))))
"Regular expression used to match numeric arguments.
If `eshell-convert-numeric-arguments' is non-nil, and an argument
matches this regexp, it will be converted to a Lisp number, using the
function `string-to-number'.")