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