1 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 2 SPDX-License-Identifier: curl 3 Long: proto 4 Arg: <protocols> 5 Help: Enable/disable PROTOCOLS 6 See-also: proto-redir proto-default 7 Added: 7.20.2 8 Category: connection curl 9 Example: --proto =http,https,sftp $URL 10 Multi: single 11 --- 12 Tells curl to limit what protocols it may use for transfers. Protocols are 13 evaluated left to right, are comma separated, and are each a protocol name or 14 'all', optionally prefixed by zero or more modifiers. Available modifiers are: 15 .RS 16 .TP 3 17 .B + 18 Permit this protocol in addition to protocols already permitted (this is 19 the default if no modifier is used). 20 .TP 21 .B - 22 Deny this protocol, removing it from the list of protocols already permitted. 23 .TP 24 .B = 25 Permit only this protocol (ignoring the list already permitted), though 26 subject to later modification by subsequent entries in the comma separated 27 list. 28 .RE 29 .IP 30 For example: 31 .RS 32 .TP 15 33 .B --proto -ftps 34 uses the default protocols, but disables ftps 35 .TP 36 .B --proto -all,https,+http 37 only enables http and https 38 .TP 39 .B --proto =http,https 40 also only enables http and https 41 .RE 42 .IP 43 Unknown and disabled protocols produce a warning. This allows scripts to 44 safely rely on being able to disable potentially dangerous protocols, without 45 relying upon support for that protocol being built into curl to avoid an error. 46 47 This option can be used multiple times, in which case the effect is the same 48 as concatenating the protocols into one instance of the option. 49