Распознавание кодировки

Code:

{

Work with codepages

(c) by Alexander Trunov, {Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.}}

unit Codepage;

interface

const

cpWin = 01;

cpAlt = 02;

cpKoi = 03;

function DetermineCodepage(const st: string): Byte;

function Alt2Win(const st: string): string;

function Win2Alt(const st: string): string;

function Alt2Koi(const st: string): string;

function Koi2Alt(const st: string): string;

function Win2Koi(const st: string): string;

function Koi2Win(const st: string): string;

function X2Y(const st: string; srcCp, dstCp: Byte): string;

implementation

const

AltSet = ['А'..'Я', 'а'..'п', 'р'..'я'];

KoiSet = ['Б'..'Р', 'Т'..'С'];

WinSet = ['а'..'п', 'р'..#255];

Win2AltTable: array[0..255] of Byte = (

   $00, $01, $02, $03, $04, $05, $06, $07, $08, $20, $0A, $0B, $0C, $0D, $0E, $0F,

   $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $1A, $1B, $1C, $1D, $1E, $1F,

   $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $2A, $2B, $2C, $2D, $2E, $2F,

   $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $3A, $3B, $3C, $3D, $3E, $3F,

   $40, $41, $42, $43, $44, $45, $46, $47, $48, $49, $4A, $4B, $4C, $4D, $4E, $4F,

   $50, $51, $52, $53, $54, $55, $56, $57, $58, $59, $5A, $5B, $5C, $5D, $5E, $5F,

   $60, $61, $62, $63, $64, $65, $66, $67, $68, $69, $6A, $6B, $6C, $6D, $6E, $6F,

   $70, $71, $72, $73, $74, $75, $76, $77, $78, $79, $7A, $7B, $7C, $7D, $7E, $7F,

   $80, $81, $82, $83, $84, $85, $86, $87, $88, $89, $8A, $8B, $8C, $8D, $8E, $8F,

   $90, $91, $92, $93, $94, $95, $96, $97, $98, $99, $9A, $9B, $9C, $9D, $9E, $9F,

   $A0, $A1, $A2, $A3, $A4, $A5, $A6, $A7, $A8, $A9, $AA, $22, $AC, $AD, $AE, $AF,

   $B0, $B1, $B2, $B3, $B4, $B5, $B6, $B7, $B8, $FC, $BA, $22, $BC, $BD, $BE, $BF,

   $80, $81, $82, $83, $84, $85, $86, $87, $88, $89, $8A, $8B, $8C, $8D, $8E, $8F,

   $90, $91, $92, $93, $94, $95, $96, $97, $98, $99, $9A, $9B, $9C, $9D, $9E, $9F,

   $A0, $A1, $A2, $A3, $A4, $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, $AE, $AF,

   $E0, $E1, $E2, $E3, $E4, $E5, $E6, $E7, $E8, $E9, $EA, $EB, $EC, $ED, $EE, $EF);

Alt2WinTable: array[0..255] of Byte = (

   $00, $01, $02, $03, $04, $05, $06, $07, $08, $09, $0A, $0B, $0C, $0D, $0E, $0F,

   $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $1A, $1B, $1C, $1D, $1E, $1F,

   $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $2A, $2B, $2C, $2D, $2E, $2F,

   $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $3A, $3B, $3C, $3D, $3E, $3F,

   $40, $41, $42, $43, $44, $45, $46, $47, $48, $49, $4A, $4B, $4C, $4D, $4E, $4F,

   $50, $51, $52, $53, $54, $55, $56, $57, $58, $59, $5A, $5B, $5C, $5D, $5E, $5F,

   $60, $61, $62, $63, $64, $65, $66, $67, $68, $69, $6A, $6B, $6C, $6D, $6E, $6F,

   $70, $71, $72, $73, $74, $75, $76, $77, $78, $79, $7A, $7B, $7C, $7D, $7E, $7F,

   $C0, $C1, $C2, $C3, $C4, $C5, $C6, $C7, $C8, $C9, $CA, $CB, $CC, $CD, $CE, $CF,

   $D0, $D1, $D2, $D3, $D4, $D5, $D6, $D7, $D8, $D9, $DA, $DB, $DC, $DD, $DE, $DF,

   $E0, $E1, $E2, $E3, $E4, $E5, $E6, $E7, $E8, $E9, $EA, $EB, $EC, $ED, $EE, $EF,

   $20, $20, $20, $A6, $A6, $A6, $A6, $2B, $2B, $A6, $A6, $2B, $2B, $2B, $2B, $2B,

   $2B, $2D, $2D, $2B, $2D, $2B, $A6, $A6, $2B, $2B, $2D, $2D, $A6, $2D, $2B, $2D,

   $2D, $2D, $2D, $2B, $2B, $2B, $2B, $2B, $2B, $2B, $2B, $5F, $5F, $5F, $5F, $5F,

   $F0, $F1, $F2, $F3, $F4, $F5, $F6, $F7, $F8, $F9, $FA, $FB, $FC, $FD, $FE, $FF,

   $A8, $B8, $AA, $BA, $AF, $BF, $A1, $A2, $B0, $B7, $B7, $5F, $B9, $A4, $5F, $5F);

Koi2AltTable: array[0..255] of Byte = (

   $00, $01, $02, $03, $04, $05, $06, $07, $08, $09, $0A, $0B, $0C, $0D, $0E, $0F,

   $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $1A, $1B, $1C, $1D, $1E, $1F,

   $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $2A, $2B, $2C, $2D, $2E, $2F,

   $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $3A, $3B, $3C, $3D, $3E, $3F,

   $40, $41, $42, $43, $44, $45, $46, $47, $48, $49, $4A, $4B, $4C, $4D, $4E, $4F,

   $50, $51, $52, $53, $54, $55, $56, $57, $58, $59, $5A, $5B, $5C, $5D, $5E, $5F,

   $60, $61, $62, $63, $64, $65, $66, $67, $68, $69, $6A, $6B, $6C, $6D, $6E, $6F,

   $70, $71, $72, $73, $74, $75, $76, $77, $78, $79, $7A, $7B, $7C, $7D, $7E, $7F,

   $80, $81, $82, $83, $84, $85, $86, $87, $88, $89, $8A, $8B, $8C, $8D, $8E, $8F,

   $90, $91, $92, $93, $94, $95, $96, $97, $98, $99, $9A, $9B, $9C, $9D, $9E, $9F,

   $A0, $A1, $A2, $A5, $A4, $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, $AE, $AF,

   $B0, $B1, $B2, $B3, $B4, $B5, $B6, $B7, $B8, $B9, $BA, $BB, $BC, $BD, $BE, $BF,

   $EE, $A0, $A1, $E6, $A4, $A5, $E4, $A3, $E5, $A8, $A9, $AA, $AB, $AC, $AD, $AE,

   $AF, $EF, $E0, $E1, $E2, $E3, $A6, $A2, $EC, $EB, $A7, $E8, $ED, $E9, $E7, $EA,

   $9E, $80, $81, $96, $84, $85, $94, $83, $95, $88, $89, $8A, $8B, $8C, $8D, $8E,

   $8F, $9F, $90, $91, $92, $93, $86, $82, $9C, $9B, $87, $98, $9D, $99, $97, $FF);

Alt2KoiTable: array[0..255] of Byte = (

   $00, $01, $02, $03, $04, $05, $06, $07, $08, $09, $0A, $0B, $0C, $0D, $0E, $0F,

   $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $1A, $1B, $1C, $1D, $1E, $1F,

   $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $2A, $2B, $2C, $2D, $2E, $2F,

   $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $3A, $3B, $3C, $3D, $3E, $3F,

   $40, $41, $42, $43, $44, $45, $46, $47, $48, $49, $4A, $4B, $4C, $4D, $4E, $4F,

   $50, $51, $52, $53, $54, $55, $56, $57, $58, $59, $5A, $5B, $5C, $5D, $5E, $5F,

   $60, $61, $62, $63, $64, $65, $66, $67, $68, $69, $6A, $6B, $6C, $6D, $6E, $6F,

   $70, $71, $72, $73, $74, $75, $76, $77, $78, $79, $7A, $7B, $7C, $7D, $7E, $7F,

   $E1, $E2, $F7, $E7, $E4, $E5, $F6, $FA, $E9, $EA, $EB, $EC, $ED, $EE, $EF, $F0,

   $F2, $F3, $F4, $F5, $E6, $E8, $E3, $FE, $FB, $FD, $9A, $F9, $F8, $FC, $E0, $F1,

   $C1, $C2, $D7, $C7, $C4, $C5, $D6, $DA, $C9, $CA, $CB, $CC, $CD, $CE, $CF, $D0,

   $B0, $B1, $B2, $B3, $B4, $B5, $B6, $B7, $B8, $B9, $BA, $BB, $BC, $BD, $BE, $BF,

   $C0, $C1, $C2, $C3, $C4, $C5, $C6, $C7, $C8, $C9, $CA, $CB, $CC, $CD, $CE, $CF,

   $D0, $D1, $D2, $D3, $D4, $D5, $D6, $D7, $D8, $D9, $DA, $DB, $DC, $DD, $DE, $DF,

   $D2, $D3, $D4, $D5, $C6, $C8, $C3, $DE, $DB, $DD, $DF, $D9, $D8, $DC, $C0, $D1,

   $85, $A3, $F2, $F3, $F4, $F5, $F6, $F7, $F8, $F9, $FA, $FB, $FC, $FD, $FE, $FF);

function X2Y(const st: string; srcCp, dstCp: Byte): string;

begin

case srcCp of

   cpWin:

     begin

       case dstCp of

         cpWin:

           begin

             Result := st;

           end;

         cpAlt:

           begin

             Result := Win2Alt(st);

           end;

         cpKoi:

           begin

             Result := Win2Koi(st);

           end;

       end;

     end;

   cpAlt:

     begin

       case dstCp of

         cpWin:

           begin

             Result := Alt2Win(st);

           end;

         cpAlt:

           begin

             Result := st;

           end;

         cpKoi:

           begin

             Result := Alt2Koi(st);

           end;

       end;

     end;

   cpKoi:

     begin

       case dstCp of

         cpWin:

           begin

             Result := Koi2Win(st);

           end;

         cpAlt:

           begin

             Result := Koi2Alt(st);

           end;

         cpKoi:

           begin

             Result := st;

           end;

       end;

     end;

end;

end;

function Win2Koi(const st: string): string;

begin

Result := Alt2Koi(Win2Alt(st));

end;

function Koi2Win(const st: string): string;

begin

Result := Alt2Win(Koi2Alt(st));

end;

function Alt2Win(const st: string): string;

var

i: Integer;

begin

Alt2Win[0] := Char(Length(st));

for i := 1 to Length(st) do

begin

   Alt2Win[i] := Char(Alt2WinTable[Byte(st[i])]);

end;

end;

function Win2Alt(const st: string): string;

var

i: Integer;

begin

Win2Alt[0] := Char(Length(st));

for i := 1 to Length(st) do

begin

   Win2Alt[i] := Char(Win2AltTable[Byte(st[i])]);

end;

end;

function Alt2Koi(const st: string): string;

var

i: Integer;

begin

Alt2Koi[0] := Char(Length(st));

for i := 1 to Length(st) do

begin

   Alt2Koi[i] := Char(Alt2KoiTable[Byte(st[i])]);

end;

end;

function Koi2Alt(const st: string): string;

var

i: Integer;

begin

Koi2Alt[0] := Char(Length(st));

for i := 1 to Length(st) do

begin

   Koi2Alt[i] := Char(Koi2AltTable[Byte(st[i])]);

end;

end;

function DetermineCodepage(const st: string): Byte;

var

WinCount,

   AltCount,

   KoiCount,

   i, rslt: Integer;

begin

DetermineCodepage := cpAlt;

WinCount := 0;

AltCount := 0;

KoiCount := 0;

for i := 1 to Length(st) do

begin

   if st[i] in AltSet then Inc(AltCount);

   if st[i] in WinSet then Inc(WinCount);

   if st[i] in KoiSet then Inc(KoiCount);

end;

DetermineCodepage := cpAlt;

if KoiCount > AltCount then

begin

   DetermineCodepage := cpKoi;

   if WinCount > KoiCount then DetermineCodepage := cpWin;

end

else

begin

   if WinCount > AltCount then DetermineCodepage := cpWin;

end;

end;

end.