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Re: Lazy load of org-protocol
Re: Lazy load of org-protocol
Sun, 6 Feb 2022 23:42:11 +0700
Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0
On 06/02/2022 01:27, Jim Porter wrote:
On 2/5/2022 3:54 AM, Max Nikulin wrote:
etc/emacsclient-mail.desktop in the Emacs repo does this.) The command
to use for a new Emacs instance is simple:
emacs -f message-mailto %u
However, doing this for emacsclient is harder:
emacsclient --alternate-editor= --create-frame --eval
There's no problem with "--alternate-editor=" and "--create-frame", but
the fact that emacsclient requires evaling the function call that way
is: if %u holds a string with quotation marks, this will break, and
worse, could even result in arbitrary code being executed. (In practice,
this is probably rare, since URLs are generally URL-encoded, and so
don't have literal quotes in them.)
Thank you for suggesting another use case.
Quoting issues was the reason why I started to search a better way.
There should be an easy and safe means to pass argument from command
line to evaluated expressions similar to shell
sh -c 'echo "$1"' example 'Hello, World!'
Some people could not even choose proper quotes for shell command:
First recipe and the accepted answer in second source solves the obvious
problem but they miss escaping for elisp expression. Another answer on
stackoverflow is more accurate, it suggests
I suppose, these links is a good illustration that substitution of
arbitrary argument into lisp expression is harder than it should be to
help users to avoid security issues.
As a result, I think a good first step might be to add support for
"--funcall" to emacsclient, just like the regular emacs binary. (The
"-f" shorthand won't work though, since emacsclient already uses that
for "--server-file"). This would simplify the `message-mailto' case
above and would also allow org-protocol to do something similar:
emacsclient --funcall org-protocol-capture %u
No, --funcall is just a sugar for --eval '(func)' that does not contain
arbitrary input, but func has no access to other arguments and it is the
I think, the solution is to add -arg command to emacs server protocol
that pushes its argument to a list and extend -exec command that would
make such list available as argv or as `command-line-args-left' for
evaluated expression. Of course, emacsclient option parser should be
modified as well to support --arg option
emacsclient --eval '(func)' --arg 1 2 3
emacsclient --eval '(func)' --arg -- 1 2 3
and maybe even for multiple eval+arg pairs
emacsclient --eval '(f1)' --arg 'a1' --eval '(f2)' --arg 'a2' 'a3'
The proper place to discuss idea is emacs-devel list, but I am afraid
that without a patch it will be just buried.
emacsclient --eval "(org-protocol-capture \\"%u\\")"
Due to quoting issues a small wrapper may be safer (modulo -a, -c)
emacsclient --eval "(require 'org-protocol)"
emacsclient -- "$@"
- Lazy load of org-protocol, Max Nikulin, 2022/02/05
- Re: Lazy load of org-protocol, Jim Porter, 2022/02/05
- Re: Lazy load of org-protocol,
Max Nikulin <=
- Re: Lazy load of org-protocol, Jim Porter, 2022/02/06
- Re: Lazy load of org-protocol, Max Nikulin, 2022/02/07
- Re: Lazy load of org-protocol, Jim Porter, 2022/02/07
- Re: Lazy load of org-protocol, Max Nikulin, 2022/02/09
- Re: Lazy load of org-protocol, Jim Porter, 2022/02/09
- Re: Lazy load of org-protocol, Max Nikulin, 2022/02/10
- Re: Emacs-orgmode Digest, Vol 192, Issue 8, Tianshu Wang, 2022/02/08