Programlama yapalım ve Öğrenelim.

neoturk: ...Search for text in textfiles ?...

unit Unit1;

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

StdCtrls, Buttons;

type

TForm1 = class(TForm)

Button1: TButton;

Memo1: TMemo;

Edit1: TEdit;

SpeedButton1: TSpeedButton;

procedure SpeedButton1Click(Sender: TObject);

private

{ Private-Deklarationen }

public

{ Public-Deklarationen }

end;

var

Form1: TForm1;

// Aus einem alten c't-Heft von C nach Delphi übersetzt

// Deklarationsteil

procedure Ts_init(P: PChar; m: Integer);

function Ts_Search(Text, p: PChar; m: Integer; Start: Longint): Longint;

// Globale Variablen

// *****************

var

shift: array[0..255] of Byte; // Shifttabelle für Turbosearch

Look_At: Integer; // Look_At-Position für Turbosearch

implementation

{$R *.DFM}

procedure Ts_init(P: PChar; m: Integer);

var

i: Integer;

begin

// *** Suchmuster analysieren ****

{1.} for i := 0 to 255 do shift[i] := m + 1;

{2.} for i := 0 to m - 1 do Shift[Ord(p[i])] := m - i;

Look_at := 0;

{3.} while (look_At < m - 1) do

begin

if (p[m - 1] = p[m - (look_at + 2)]) then Exit

else

Inc(Look_at, 1);

end;

// *** Beschreibung ****

// 1. Sprungtabelle Shift[0..255] wird mit der max. Sprungweite (Musterlänge+1)

// initialisiert.

// 2. Für jedes Zeichen im Muster wird seine Position (von hinten gezählt) in

// der Shift-Tabelle eingetragen.

// Für das Muster "Hans" würden folgende Shiftpositionen ermittelt werde:

// Für H = ASCII-Wert = 72d ,dass von hinten gezählt an der 4. Stelle ist,

// wird Shift[72] := 4 eingetragen.

// Für a = 97d = Shift[97] := 3;

// Für n = 110d = Shift[110] := 2;

// Für s = 115d = Shift[115] := 1;

// Da das Muster von Vorn nach Hinten durchsucht wird, sind doppelt auf-

// tretende Zeichen kein Problem. Die Shift-Werte werden überschrieben und

// mit der kleinsten Sprungweite automatisch aktualisiert.

// 3. Untersucht wo (position von hinten) das Letzte Zeichen im Muster

// nochmals vorkommt und Speichert diese in der Variable Look_AT.

// Die Maximale Srungweite beim Suchen kann also 2*Musterlänge sein wenn

// das letzte Zeichen nur einmal im Muster vorhanden ist.

end;

function Ts_Search(Text, p: PChar; m: Integer; Start: Longint): Longint;

var

I: Longint;

T: PChar;

begin

T := Text + Start; // Zeiger auf Startposition im Text setzen

Result := -1;

repeat

i := m - 1;

// Letztes Zeichen des Suchmusters im Text suchen.

while (t[i] <> p[i]) do t := t + shift[Ord(t[m])];

i := i - 1; // Vergleichszeiger auf vorletztes Zeichen setzen

if i < 0 then i := 0; // wenn nach nur einem Zeichen gesucht wird,

// kann i = -1 werden.

// restliche Zeichen des Musters vergleichen

while (t[i] = p[i]) do

begin

if i = 0 then Result := t - Text;

i := i - 1;

end;

// Muster nicht gefunden -> Sprung um max. 2*m

if Result = -1 then t := t + Look_AT + shift[Ord(t[m + look_at])];

until Result <> -1; // Repeat

end;

// Such-Procedure auslösen (hier beim drücken eines Speedbuttons auf FORM1)

procedure TForm1.SpeedButton1Click(Sender: TObject);

var

tt: string;

L: Integer;

L2, sp, a: Longint;

F: file; // File-Alias

Size: Integer; // Textlänge

Buffer: PChar; // Text-Memory-Buffer

begin

tt := Edit1.Text; // Suchmuster

L := Length(TT); // Suchmusterlänge

ts_init(PChar(TT), L); // Sprungtabelle für Suchmuster initialisieren

try

AssignFile(F, 'test.txt');

Reset(F, 1); // File öffnen

Size := FileSize(F); // Filegrösse ermitteln

GetMem(Buffer, Size + L + 1); // Memory reservieren in der Grösse von

// TextFilelänge+Musterlänge+1

try

BlockRead(F, Buffer^, Size); // Filedaten in den Buffer füllen

StrCat(Buffer, PChar(TT)); // Suchmuster ans Ende des Textes anhängen

// damit der Suchalgorythmus keine Fileende-

// Kontrolle machen muss.

// Turbo-Search

SP := 0; // Startpunkt der Suche im Text

A := 0; // Anzahl-gefunden-Zähler

while SP < Size do

begin

L2 := Ts_Search(Buffer, PChar(TT), L, SP); // L = Musterlänge

// SP= Startposition im Text

SP := L2 + L; // StartPosition auf Letzte gefundene Position+Musterlänge

Inc(a); // Anzahl gefunden Zähler

end;

// Am Schluss nicht vergessen Buffer freigeben und Inputfile schliessen

finally

FreeMem(Buffer); // Memory freigeben.

end;

finally

CloseFile(F); // Datei schliessen.

end;

end.

Delphi - .....................................

neoturk: ...Identifying a file through crc-32 ?...

// The constants here are for the CRC-32 generator

// polynomial, as defined in the Microsoft

// Systems Journal, March 1995, pp. 107-108

const

Table: array[0..255] of DWORD =

($00000000, $77073096, $EE0E612C, $990951BA,

$076DC419, $706AF48F, $E963A535, $9E6495A3,

$0EDB8832, $79DCB8A4, $E0D5E91E, $97D2D988,

$09B64C2B, $7EB17CBD, $E7B82D07, $90BF1D91,

$1DB71064, $6AB020F2, $F3B97148, $84BE41DE,

$1ADAD47D, $6DDDE4EB, $F4D4B551, $83D385C7,

$136C9856, $646BA8C0, $FD62F97A, $8A65C9EC,

$14015C4F, $63066CD9, $FA0F3D63, $8D080DF5,

$3B6E20C8, $4C69105E, $D56041E4, $A2677172,

$3C03E4D1, $4B04D447, $D20D85FD, $A50AB56B,

$35B5A8FA, $42B2986C, $DBBBC9D6, $ACBCF940,

$32D86CE3, $45DF5C75, $DCD60DCF, $ABD13D59,

$26D930AC, $51DE003A, $C8D75180, $BFD06116,

$21B4F4B5, $56B3C423, $CFBA9599, $B8BDA50F,

$2802B89E, $5F058808, $C60CD9B2, $B10BE924,

$2F6F7C87, $58684C11, $C1611DAB, $B6662D3D,

$76DC4190, $01DB7106, $98D220BC, $EFD5102A,

$71B18589, $06B6B51F, $9FBFE4A5, $E8B8D433,

$7807C9A2, $0F00F934, $9609A88E, $E10E9818,

$7F6A0DBB, $086D3D2D, $91646C97, $E6635C01,

$6B6B51F4, $1C6C6162, $856530D8, $F262004E,

$6C0695ED, $1B01A57B, $8208F4C1, $F50FC457,

$65B0D9C6, $12B7E950, $8BBEB8EA, $FCB9887C,

$62DD1DDF, $15DA2D49, $8CD37CF3, $FBD44C65,

$4DB26158, $3AB551CE, $A3BC0074, $D4BB30E2,

$4ADFA541, $3DD895D7, $A4D1C46D, $D3D6F4FB,

$4369E96A, $346ED9FC, $AD678846, $DA60B8D0,

$44042D73, $33031DE5, $AA0A4C5F, $DD0D7CC9,

$5005713C, $270241AA, $BE0B1010, $C90C2086,

$5768B525, $206F85B3, $B966D409, $CE61E49F,

$5EDEF90E, $29D9C998, $B0D09822, $C7D7A8B4,

$59B33D17, $2EB40D81, $B7BD5C3B, $C0BA6CAD,

$EDB88320, $9ABFB3B6, $03B6E20C, $74B1D29A,

$EAD54739, $9DD277AF, $04DB2615, $73DC1683,

$E3630B12, $94643B84, $0D6D6A3E, $7A6A5AA8,

$E40ECF0B, $9309FF9D, $0A00AE27, $7D079EB1,

$F00F9344, $8708A3D2, $1E01F268, $6906C2FE,

$F762575D, $806567CB, $196C3671, $6E6B06E7,

$FED41B76, $89D32BE0, $10DA7A5A, $67DD4ACC,

$F9B9DF6F, $8EBEEFF9, $17B7BE43, $60B08ED5,

$D6D6A3E8, $A1D1937E, $38D8C2C4, $4FDFF252,

$D1BB67F1, $A6BC5767, $3FB506DD, $48B2364B,

$D80D2BDA, $AF0A1B4C, $36034AF6, $41047A60,

$DF60EFC3, $A867DF55, $316E8EEF, $4669BE79,

$CB61B38C, $BC66831A, $256FD2A0, $5268E236,

$CC0C7795, $BB0B4703, $220216B9, $5505262F,

$C5BA3BBE, $B2BD0B28, $2BB45A92, $5CB36A04,

$C2D7FFA7, $B5D0CF31, $2CD99E8B, $5BDEAE1D,

$9B64C2B0, $EC63F226, $756AA39C, $026D930A,

$9C0906A9, $EB0E363F, $72076785, $05005713,

$95BF4A82, $E2B87A14, $7BB12BAE, $0CB61B38,

$92D28E9B, $E5D5BE0D, $7CDCEFB7, $0BDBDF21,

$86D3D2D4, $F1D4E242, $68DDB3F8, $1FDA836E,

$81BE16CD, $F6B9265B, $6FB077E1, $18B74777,

$88085AE6, $FF0F6A70, $66063BCA, $11010B5C,

$8F659EFF, $F862AE69, $616BFFD3, $166CCF45,

$A00AE278, $D70DD2EE, $4E048354, $3903B3C2,

$A7672661, $D06016F7, $4969474D, $3E6E77DB,

$AED16A4A, $D9D65ADC, $40DF0B66, $37D83BF0,

$A9BCAE53, $DEBB9EC5, $47B2CF7F, $30B5FFE9,

$BDBDF21C, $CABAC28A, $53B39330, $24B4A3A6,

$BAD03605, $CDD70693, $54DE5729, $23D967BF,

$B3667A2E, $C4614AB8, $5D681B02, $2A6F2B94,

$B40BBE37, $C30C8EA1, $5A05DF1B, $2D02EF8D);

type

//----------------------------------crc32----------------------------------

{$IFDEF VER130} // This is a bit awkward

// 8-byte integer

TInteger8 = Int64; // Delphi 5

{$ELSE}

{$IFDEF VER120}

TInteger8 = Int64; // Delphi 4

{$ELSE}

TInteger8 = COMP; // Delphi 2 or 3

{$ENDIF}

//----------------------------------crc32----------------------------------

// Use CalcCRC32 as a procedure so CRCValue can be passed in but

// also returned. This allows multiple calls to CalcCRC32 for

// the "same" CRC-32 calculation.

procedure CalcCRC32(p: Pointer; ByteCount: DWORD; var CRCValue: DWORD);

// The following is a little cryptic (but executes very quickly).

// The algorithm is as follows:

// 1. exclusive-or the input byte with the low-order byte of

// the CRC register to get an INDEX

// 2. shift the CRC register eight bits to the right

// 3. exclusive-or the CRC register with the contents of Table[INDEX]

// 4. repeat steps 1 through 3 for all bytes

var

i: DWORD;

q: ^BYTE;

begin

q := p;

for i := 0 to ByteCount - 1 do

begin

CRCvalue := (CRCvalue shr 8) xor

Table[q^ xor (CRCvalue and $000000FF)];

Inc(q)

end

end {CalcCRC32};

function CalcStringCRC32(s: string; out CRC32: DWORD): Boolean;

var

CRC32Table: DWORD;

begin

// Verify the table used to compute the CRCs has not been modified.

// Thanks to Gary Williams for this suggestion, Jan. 2003.

CRC32Table := $FFFFFFFF;

CalcCRC32(Addr(Table[0]), SizeOf(Table), CRC32Table);

CRC32Table := not CRC32Table;

if CRC32Table <> $6FCF9E13 then ShowMessage('CRC32 Table CRC32 is ' +

IntToHex(Crc32Table, 8) +

', expecting $6FCF9E13')

else

begin

CRC32 := $FFFFFFFF; // To match PKZIP

if Length(s) > 0 // Avoid access violation in D4

then CalcCRC32(Addr(s[1]), Length(s), CRC32);

CRC32 := not CRC32; // To match PKZIP

end;

procedure CalcFileCRC32(FromName: string; var CRCvalue: DWORD;

var TotalBytes: TInteger8;

var error: Word);

var

Stream: TMemoryStream;

begin

error := 0;

CRCValue := $FFFFFFFF;

Stream := TMemoryStream.Create;

try

Stream.LoadFromFile(FromName);

if Stream.Size > 0 then CalcCRC32(Stream.Memory, Stream.Size, CRCvalue)

except

on E: EReadError do

error := 1

end;

CRCvalue := not CRCvalue

finally

Stream.Free

end;

procedure TForm1.Button1Click(Sender: TObject);

var

s: string;

CRC32: DWORD;

begin

s := 'Test String';

if CalcStringCRC32(s, CRC32) then

ShowMessage(IntToStr(crc32));

end;

Delphi - .....................................

neoturk: ...Identifying a file through crc-32 ?...

// The constants here are for the CRC-32 generator

// polynomial, as defined in the Microsoft

// Systems Journal, March 1995, pp. 107-108

const

Table: array[0..255] of DWORD =

($00000000, $77073096, $EE0E612C, $990951BA,

$076DC419, $706AF48F, $E963A535, $9E6495A3,

$0EDB8832, $79DCB8A4, $E0D5E91E, $97D2D988,

$09B64C2B, $7EB17CBD, $E7B82D07, $90BF1D91,

$1DB71064, $6AB020F2, $F3B97148, $84BE41DE,

$1ADAD47D, $6DDDE4EB, $F4D4B551, $83D385C7,

$136C9856, $646BA8C0, $FD62F97A, $8A65C9EC,

$14015C4F, $63066CD9, $FA0F3D63, $8D080DF5,

$3B6E20C8, $4C69105E, $D56041E4, $A2677172,

$3C03E4D1, $4B04D447, $D20D85FD, $A50AB56B,

$35B5A8FA, $42B2986C, $DBBBC9D6, $ACBCF940,

$32D86CE3, $45DF5C75, $DCD60DCF, $ABD13D59,

$26D930AC, $51DE003A, $C8D75180, $BFD06116,

$21B4F4B5, $56B3C423, $CFBA9599, $B8BDA50F,

$2802B89E, $5F058808, $C60CD9B2, $B10BE924,

$2F6F7C87, $58684C11, $C1611DAB, $B6662D3D,

$76DC4190, $01DB7106, $98D220BC, $EFD5102A,

$71B18589, $06B6B51F, $9FBFE4A5, $E8B8D433,

$7807C9A2, $0F00F934, $9609A88E, $E10E9818,

$7F6A0DBB, $086D3D2D, $91646C97, $E6635C01,

$6B6B51F4, $1C6C6162, $856530D8, $F262004E,

$6C0695ED, $1B01A57B, $8208F4C1, $F50FC457,

$65B0D9C6, $12B7E950, $8BBEB8EA, $FCB9887C,

$62DD1DDF, $15DA2D49, $8CD37CF3, $FBD44C65,

$4DB26158, $3AB551CE, $A3BC0074, $D4BB30E2,

$4ADFA541, $3DD895D7, $A4D1C46D, $D3D6F4FB,

$4369E96A, $346ED9FC, $AD678846, $DA60B8D0,

$44042D73, $33031DE5, $AA0A4C5F, $DD0D7CC9,

$5005713C, $270241AA, $BE0B1010, $C90C2086,

$5768B525, $206F85B3, $B966D409, $CE61E49F,

$5EDEF90E, $29D9C998, $B0D09822, $C7D7A8B4,

$59B33D17, $2EB40D81, $B7BD5C3B, $C0BA6CAD,

$EDB88320, $9ABFB3B6, $03B6E20C, $74B1D29A,

$EAD54739, $9DD277AF, $04DB2615, $73DC1683,

$E3630B12, $94643B84, $0D6D6A3E, $7A6A5AA8,

$E40ECF0B, $9309FF9D, $0A00AE27, $7D079EB1,

$F00F9344, $8708A3D2, $1E01F268, $6906C2FE,

$F762575D, $806567CB, $196C3671, $6E6B06E7,

$FED41B76, $89D32BE0, $10DA7A5A, $67DD4ACC,

$F9B9DF6F, $8EBEEFF9, $17B7BE43, $60B08ED5,

$D6D6A3E8, $A1D1937E, $38D8C2C4, $4FDFF252,

$D1BB67F1, $A6BC5767, $3FB506DD, $48B2364B,

$D80D2BDA, $AF0A1B4C, $36034AF6, $41047A60,

$DF60EFC3, $A867DF55, $316E8EEF, $4669BE79,

$CB61B38C, $BC66831A, $256FD2A0, $5268E236,

$CC0C7795, $BB0B4703, $220216B9, $5505262F,

$C5BA3BBE, $B2BD0B28, $2BB45A92, $5CB36A04,

$C2D7FFA7, $B5D0CF31, $2CD99E8B, $5BDEAE1D,

$9B64C2B0, $EC63F226, $756AA39C, $026D930A,

$9C0906A9, $EB0E363F, $72076785, $05005713,

$95BF4A82, $E2B87A14, $7BB12BAE, $0CB61B38,

$92D28E9B, $E5D5BE0D, $7CDCEFB7, $0BDBDF21,

$86D3D2D4, $F1D4E242, $68DDB3F8, $1FDA836E,

$81BE16CD, $F6B9265B, $6FB077E1, $18B74777,

$88085AE6, $FF0F6A70, $66063BCA, $11010B5C,

$8F659EFF, $F862AE69, $616BFFD3, $166CCF45,

$A00AE278, $D70DD2EE, $4E048354, $3903B3C2,

$A7672661, $D06016F7, $4969474D, $3E6E77DB,

$AED16A4A, $D9D65ADC, $40DF0B66, $37D83BF0,

$A9BCAE53, $DEBB9EC5, $47B2CF7F, $30B5FFE9,

$BDBDF21C, $CABAC28A, $53B39330, $24B4A3A6,

$BAD03605, $CDD70693, $54DE5729, $23D967BF,

$B3667A2E, $C4614AB8, $5D681B02, $2A6F2B94,

$B40BBE37, $C30C8EA1, $5A05DF1B, $2D02EF8D);

type

//----------------------------------crc32----------------------------------

{$IFDEF VER130} // This is a bit awkward

// 8-byte integer

TInteger8 = Int64; // Delphi 5

{$ELSE}

{$IFDEF VER120}

TInteger8 = Int64; // Delphi 4

{$ELSE}

TInteger8 = COMP; // Delphi 2 or 3

{$ENDIF}

//----------------------------------crc32----------------------------------

// Use CalcCRC32 as a procedure so CRCValue can be passed in but

// also returned. This allows multiple calls to CalcCRC32 for

// the "same" CRC-32 calculation.

procedure CalcCRC32(p: Pointer; ByteCount: DWORD; var CRCValue: DWORD);

// The following is a little cryptic (but executes very quickly).

// The algorithm is as follows:

// 1. exclusive-or the input byte with the low-order byte of

// the CRC register to get an INDEX

// 2. shift the CRC register eight bits to the right

// 3. exclusive-or the CRC register with the contents of Table[INDEX]

// 4. repeat steps 1 through 3 for all bytes

var

i: DWORD;

q: ^BYTE;

begin

q := p;

for i := 0 to ByteCount - 1 do

begin

CRCvalue := (CRCvalue shr 8) xor

Table[q^ xor (CRCvalue and $000000FF)];

Inc(q)

end

end {CalcCRC32};

function CalcStringCRC32(s: string; out CRC32: DWORD): Boolean;

var

CRC32Table: DWORD;

begin

// Verify the table used to compute the CRCs has not been modified.

// Thanks to Gary Williams for this suggestion, Jan. 2003.

CRC32Table := $FFFFFFFF;

CalcCRC32(Addr(Table[0]), SizeOf(Table), CRC32Table);

CRC32Table := not CRC32Table;

if CRC32Table <> $6FCF9E13 then ShowMessage('CRC32 Table CRC32 is ' +

IntToHex(Crc32Table, 8) +

', expecting $6FCF9E13')

else

begin

CRC32 := $FFFFFFFF; // To match PKZIP

if Length(s) > 0 // Avoid access violation in D4

then CalcCRC32(Addr(s[1]), Length(s), CRC32);

CRC32 := not CRC32; // To match PKZIP

end;

procedure CalcFileCRC32(FromName: string; var CRCvalue: DWORD;

var TotalBytes: TInteger8;

var error: Word);

var

Stream: TMemoryStream;

begin

error := 0;

CRCValue := $FFFFFFFF;

Stream := TMemoryStream.Create;

try

Stream.LoadFromFile(FromName);

if Stream.Size > 0 then CalcCRC32(Stream.Memory, Stream.Size, CRCvalue)

except

on E: EReadError do

error := 1

end;

CRCvalue := not CRCvalue

finally

Stream.Free

end;

procedure TForm1.Button1Click(Sender: TObject);

var

s: string;

CRC32: DWORD;

begin

s := 'Test String';

if CalcStringCRC32(s, CRC32) then

ShowMessage(IntToStr(crc32));

end;

Delphi - .....................................

neoturk: ...Get the modify date of files ?...

function GetFileModifyDate(FileName: string): TDateTime;

var

h: THandle;

Struct: TOFSTRUCT;

lastwrite: Integer;

t: TDateTime;

begin

h := OpenFile(PChar(FileName), Struct, OF_SHARE_DENY_NONE);

try

if h <> HFILE_ERROR then

begin

lastwrite := FileGetDate(h);

Result := FileDateToDateTime(lastwrite);

end;

finally

CloseHandle(h);

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

if Opendialog1.Execute then

label1.Caption := FormatDateTime('dddd, d. mmmm yyyy hh:mm:ss',

GetFileModifyDate(Opendialog1.FileName));

end;