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