Document VIS_HTTPSTYLE:

VIS_HTTPSTYLE is a new encoding style for use in vis(), strvis() and
  strvisx() that escapes characters according to RFC 1808 (URI encoding).

Since decoding of these require different detection of start-points of
  escaped characters, VIS_HTTPSTYLE can be given as flag to unvis().
  unvis() will then properly decode URIs.

A new function appeared, strunvisx(): strunvisx() behaves similar as
  strunvis(), with one exception: It has an additional flag parameter,
  which is passed to unvis() to archive the effect I described above.

1 files changed, 8 insertions, 1 deletions

diff --git a/lib/libc/gen/vis.3 b/lib/libc/gen/vis.3
index 88d5b52..7612bd5 100644
--- a/lib/libc/gen/vis.3
+++ b/lib/libc/gen/vis.3
@@ -162,7 +162,7 @@ All forms use the backslash character
 to introduce a special
 sequence; two backslashes are used to represent a real backslash.
 These are the visual formats:
-.Bl -tag -width VIS_CSTYLE
+.Bl -tag -width VIS_HTTPSTYLE
 .It (default)
 Use an
 .Ql M
@@ -238,6 +238,13 @@ If
 .Fa nextc
 is an octal digit, the latter representation is used to
 avoid ambiguity.
+.It Dv VIS_HTTPSTYLE
+Use URI encoding as described in RFC 1808.
+The form is
+.Ql %dd
+where
+.Em d
+represents a hexadecimal digit.
 .It Dv VIS_OCTAL
 Use a three digit octal sequence.  The form is
 .Ql \eddd