rebol [ encoding: 'cp1250 title: "quoted-printable encoder" file: %qp-encode.r purpose: {Encodes the string data to quoted-printable format} author: "Oldes" email: %oliva--david--seznam--cz date: 27-Mar-2008/9:16:36+1:00 version: 2.0.0 history: [ 2.0.0 [27-Mar-2008 "oldes" "completely new version"] 1.0.0 [20-Jun-2002 "oldes" "first version"] ] usage: [ qp-encode "nejzajímavìjší" ;== "nejzaj=EDmav=ECj=9A=ED" ] comment: {More info about this encoding: http://www.faqs.org/rfcs/rfc2045.html} library: [ level: intermediate platform: all type: function domain: [email text-processing] tested-under: none support: none license: 'pd see-also: none ] ] qp-encode: func[ "Encodes the string data to quoted-printable format" str [any-string!] "string to encode" /with chars [string! bitset!] "additional characters to encode" /local tmp r safe-chars rest out h ][ r: 76 safe-chars: charset [#"!" - #"<" #">" - #"~" #" "] if with [ safe-chars: exclude safe-chars either string? chars [charset chars][chars] ] rest: complement safe-chars out: copy "" parse/all copy str [ any [ ( ;test, if there is space on row if r = 0 [ out: insert out "=^M^/" r: 76 ] ) copy tmp r safe-chars h: ( ; if there is enough safe-chars to fill the max row length out: insert out tmp unless tail? h [out: insert out "=^M^/"] r: 76 ) | copy tmp some safe-chars ( ; takes safe-chars, still some space left on row out: insert out tmp r: r - length? tmp ) | copy tmp rest ( ; encode not safe-char if r < 3 [ out: insert out "=^M^/" r: 76 ] out: insert out join "=" enbase/base tmp 16 r: r - 3 ) ] ] head out ]