读取环境变量是用 doom-load-envvars-file ，调试时发现是因为 (re-search-forward "\0\n *\\([^#= \n]*\\)=" nil t) 查不到任何东西，将 \0\n 换成 \n 后正常。请教有人知道 \0\n 和 \n这两者的区别吗？
(defun doom-load-envvars-file (file &optional noerror)
"Read and set envvars from FILE.
If NOERROR is non-nil, don't throw an error if the file doesn't exist or is
unreadable. Returns the names of envvars that were changed."
(if (null (file-exists-p file))
(unless noerror
(signal 'file-error (list "No envvar file exists" file)))
(when-let
(env
(with-temp-buffer
(save-excursion
(setq-local coding-system-for-read 'utf-8)
(insert "\0\n") ; to prevent off-by-one
(insert-file-contents file))
(save-match-data
(when (re-search-forward "\0\n *\\([^#= \n]*\\)=" nil t)
(setq
env (split-string (buffer-substring (match-beginning 1) (point-max))
"\0\n"
'omit-nulls))))))
(setq-default
process-environment
(append (nreverse env)
(default-value 'process-environment))
exec-path
(append (split-string (getenv "PATH") path-separator t)
(list exec-directory))
shell-file-name
(or (getenv "SHELL")
(default-value 'shell-file-name)))
env)))