Function: eshell-duplicate-handles

eshell-duplicate-handles is a byte-compiled function defined in esh-io.el.gz.

Signature

(eshell-duplicate-handles HANDLES)

Documentation

Create a duplicate of the file handles in HANDLES.

This uses the targets of each handle in HANDLES, incrementing its reference count by one. These targets are shared between the original set of handles and the new one, so the targets are only closed when the reference count drops to 0 (see eshell-close-handles).

This function also sets the DEFAULT field for each handle to t (see eshell-create-handles). Unlike the targets, this value is not shared with the original handles.

Source Code

;; Defined in /usr/src/emacs/lisp/eshell/esh-io.el.gz
(defun eshell-duplicate-handles (handles &optional steal-p)
  "Create a duplicate of the file handles in HANDLES.
This uses the targets of each handle in HANDLES, incrementing its
reference count by one.  These targets are shared between the original
set of handles and the new one, so the targets are only closed when the
reference count drops to 0 (see `eshell-close-handles').

This function also sets the DEFAULT field for each handle to
t (see `eshell-create-handles').  Unlike the targets, this value
is not shared with the original handles."
  (declare (advertised-calling-convention (handles) "31.1"))
  (let ((dup-handles (make-vector eshell-number-of-handles nil)))
    (dotimes (idx eshell-number-of-handles)
      (when-let* ((handle (aref handles idx)))
        (unless steal-p
          (incf (cdar handle)))
        (aset dup-handles idx (list (car handle) t))))
    dup-handles))