curl/docs/cmdline-opts/proto.md
Daniel Stenberg daa8693619
VERSIONS: list all past releases
This document now lists all previous releases.

This allows us to verify that documentation refers to actual release
versions.

Test 971 now verifies options-in-versions and all command line options
documentation individually. Fixed a few discrepancies.

Test 1488 verifies libcurl options "Added-in" to exist. Fixed a few
discrepancies there as well.

Closes #16907
2025-04-03 08:26:33 +02:00

48 lines
1.4 KiB
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: proto
Arg: <protocols>
Help: Enable/disable PROTOCOLS
Added: 7.21.0
Category: connection curl
Multi: single
See-also:
- proto-redir
- proto-default
Example:
- --proto =http,https,sftp $URL
---
# `--proto`
Limit what protocols to allow for transfers. Protocols are evaluated left to
right, are comma separated, and are each a protocol name or 'all', optionally
prefixed by zero or more modifiers. Available modifiers are:
## +
Permit this protocol in addition to protocols already permitted (this is
the default if no modifier is used).
## -
Deny this protocol, removing it from the list of protocols already permitted.
## =
Permit only this protocol (ignoring the list already permitted), though
subject to later modification by subsequent entries in the comma separated
list.
##
For example: --proto -ftps uses the default protocols, but disables ftps
--proto -all,https,+http only enables http and https
--proto =http,https also only enables http and https
Unknown and disabled protocols produce a warning. This allows scripts to
safely rely on being able to disable potentially dangerous protocols, without
relying upon support for that protocol being built into curl to avoid an error.
This option can be used multiple times, in which case the effect is the same
as concatenating the protocols into one instance of the option.