eshell-find-delimiter
eshell-find-delimiter is a compiled Lisp function in `esh-util.el
'.
(eshell-find-delimiter OPEN CLOSE &optional BOUND REVERSE-P BACKSLASH-P)
From point, find the CLOSE delimiter corresponding to OPEN.
The matching is bounded by BOUND.
If REVERSE-P is non-nil, process the region backwards.
If BACKSLASH-P is non-nil, and OPEN and CLOSE are the same character,
then quoting is done by a backslash, rather than a doubled delimiter.