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Re: [Discussion] Have curl honor OpenSSH configurations

From: Timothe Litt <>
Date: Thu, 11 Aug 2022 12:38:13 -0400

On 11-Aug-22 10:23, Randall via curl-library wrote:
> Was
> Originally opened by Ben Voris. The request was to have curl support OpenSSH
> config specifications. I am opening a discussion on this subject from the
> above case. The ask is whether it would make sense to have an option to
> allow curl to honor ~/.ssh/config while attempting to connect?
> Ben Voris has a significant usability point in the case, including: " I had
> hoped that because curl libssh and libssh uses OpenSSH, it would honor the
> config file and so allow curl to behave like OpenSSH clients."
> Many software projects other than OpenSSH honor ~/.ssh/config. An option in
> curl like --use-ssh-config might be something of value even if not the
> default.
> Regards,
> Randall
> --
> Brief whoami: NonStop&UNIX developer since approximately
> UNIX(421664400)
> NonStop(211288444200000000)
> -- In real life, I talk too much.
This seems like the wrong way to approach the original request (stated
on github)  for several reasons.

Reading other commands' config files creates unmanaged dependencies on
those projects - formats, options, and/or defaults may or may not be
stable.  Which commands deserve this treatment is also unbounded -
should curl read ~/.ftp?  .mx? .freepopsd? .firefox? .gopher? .tftp?
.telnet?  ...  Besides reading the config files in ~, what about
/etc/sysconfig (or /etc/default)? And the commands that scan a .d
directory for additional config files?  Really, this gets out of hand
really, really fast.

It seems more reasonable to have a --default-port option, then put it in
~/.curlrc or use --config.  E.g.

curl --config $(HOST).curl.ssh.cfg

where might contain

default-port 65534

(and any other useful options - perhaps proxy to use, --compressed-ssh,

Or simply (with no change required to curl)

url = "s"

Or have the makefile extract the port number from your HOST variable
when generating the ssh command.  Or have the makefile generate a
suitable --config as a temporary file.

Or (more generally useful) extend the curl config file syntax to have
per-host options, e.g. perhaps


default-port 65534


default-port 43556



There are other reasonable solutions, but reading other commands config
files isn't one of them.

Timothe Litt
ACM Distinguished Engineer
This communication may not represent the ACM or my employer's views,
if any, on the matters discussed.

Received on 2022-08-11