Re: [apps-discuss] Fwd: I-D Action: draft-yevstifeyev-ftp-uri-scheme-04.txt

[Frank Ellermann <[e-mail]>]

On 14 July 2011 05:29, Mykyta Yevstifeyev wrote:

> "@" is in <gen-delims>, so we can safely assume that it won't
> apper anywhere else except the authority non-percent-encoded.

Quoting RFC 3986 section 3.3, page 23:

 segment-nz-nc = 1*( unreserved / pct-encoded / sub-delims / "@" )
                   ; non-zero-length segment without any colon ":"

 pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"


That allows an unencoded '@' in the <path>, not the '@' you are
interested in while trying to skip any <userinfo>@.

 query         = *( pchar / "/" / "?" )

Ditto, unencoded '@' in the <query> (section 3.4, page 24).

  fragment     = *( pchar / "/" / "?" )

Ditto, unencoded '@' in the <fragment> (section 3.5, page 24).


> it is also assumed that there will be no "@" chars before the
> "@" delimiting userinfo from host

ACK, all parts of the <authority> including odd beasts such as
a <reg-name> or <IPvFuture> do not permit unencoded '@' (apart
from the <userinfo>@ case).

> So, "@" will normally occur only 1 time, and won't occur in
> the <userinfo> itself, query or fragment identifier.

See above wrt <path>, <query>, and <fragment>.  I recall that
it took me more than a year to grok the fine print in STD 66.

-Frank