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Search in files

Posted on 2000-04-02
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Last Modified: 2010-04-04
How can I search a string in the list of text files?

Thanks
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Question by:shtern
  • 4
6 Comments
 
LVL 17

Accepted Solution

by:
inthe earned 50 total points
ID: 2678204
hi,
use the pos function like below:

procedure TForm1.Button2Click(Sender: TObject);
begin
if pos('boo',edit1.text)<>0 then showmessage('textfound')else showmessage('no found');
end;


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LVL 17

Expert Comment

by:inthe
ID: 2678207
or you could use a tfinddialog fo text in a richedit:

procedure TForm1.Button1Click(Sender: TObject);
begin
FindDialog1.Execute;
end;

procedure TForm1.FindDialog1Find(Sender: TObject);
var
  FoundAt: LongInt;
begin
  with RichEdit1 do  begin
    FoundAt := Pos(FindDialog1.FindText, Text) - 1;
    if (FoundAt <> 0) then
    begin
      SetFocus;
      SelStart := FoundAt;
      SelLength := Length(FindDialog1.FindText);
      SelAttributes.Color:=clred;
      SelAttributes.style := [fsbold];
      clearselection;
    end;
  end;
end;
0
 
LVL 17

Expert Comment

by:inthe
ID: 2678210
or you could use a tfinddialog fo text in a richedit:

procedure TForm1.Button1Click(Sender: TObject);
begin
FindDialog1.Execute;
end;

procedure TForm1.FindDialog1Find(Sender: TObject);
var
  FoundAt: LongInt;
begin
  with RichEdit1 do  begin
    FoundAt := Pos(FindDialog1.FindText, Text) - 1;
    if (FoundAt <> 0) then
    begin
      SetFocus;
      SelStart := FoundAt;
      SelLength := Length(FindDialog1.FindText);
      SelAttributes.Color:=clred;
      SelAttributes.style := [fsbold];
      clearselection;
    end;
  end;
end;
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Author Comment

by:shtern
ID: 2678244
Hi, inthe,
sorry, I don't understand. As it stays in Delphi help, pos function finds just a substring in a string. Your second comment is nearer, but I need to search in  a lot of files (not in one which I can load in Richedit), e.g.  find files in a directory which contain my string, not in filename, but in contents.
0
 
LVL 17

Expert Comment

by:inthe
ID: 2678465
ok ,
i had a quick look and found this,i havent time to test till tommorrow ,
but it will help you on your way for now,hope its more what you were after.

<start paste>

there are two tasks here: scanning the disk(s) for files with a set of extensions and scanning each file found for the phrase. In short, you want a Grep utility <g>. I'm sure you could find something on the usual Delphi websites ,dsp for instance:
http://sunsite.icm.edu.pl/delphi/
using GREP as search word.
 
Anyway, part 1 is a recursive FindFirst/FindNext loop. Here is a sample for that, which you will have to adapt to integrate the search for a phrase:
 
recursively scanning all drives
 
  { excerpt from form declaration, form has a listbox1 for the
    results, a label1 for progress, a button2 to start the scan,     an edit1 to get the search mask from, a button3 to stop
    the scan. }
  private
    { Private declarations }
    FScanAborted: Boolean;
 
  public
    { Public declarations }
    Function ScanDrive( root, filemask: String; hitlist: TStrings ): Boolean;
 
 
Function TForm1.ScanDrive( root, filemask: String; hitlist: TStrings ): Boolean;
  Function ScanDirectory( Var path: String ): Boolean;
    Var
      SRec: TSearchRec;
      pathlen: Integer;
      res: Integer;
    Begin
      label1.caption := path;
      pathlen:= Length(path);
      { first pass, files }
      res := FindFirst( path+filemask, faAnyfile, SRec );
      If res = 0 Then
      try
        While res = 0 Do Begin
          hitlist.Add( path + SRec.Name );
          res := FindNext(SRec);
        End;
      finally
        FindClose(SRec)
      end;
      Application.ProcessMessages;
      Result := not (FScanAborted or Application.Terminated);
      If not Result Then Exit;
 
      {second pass, directories}
      res := FindFirst( path+'*.*', faDirectory, SRec );
      If res = 0 Then
      try
        While (res = 0) and Result Do Begin
          If ((Srec.Attr and faDirectory) = faDirectory) and
            (Srec.name[1] <> '.')
          Then Begin
            path := path + SRec.name + '\';
            Result := ScanDirectory( path );
            SetLength( path, pathlen );
          End;
          res := FindNext(SRec);
        End;
      finally
        FindClose(SRec)
      end;
    End;
Begin
  FScanAborted := False;
  Screen.Cursor := crHourglass;
  try
    Result := ScanDirectory(root);
  finally
    Screen.Cursor := crDefault
  end;
End;
 
procedure TForm1.Button2Click(Sender: TObject);
Var
  ch: Char;
  root: String;
Begin
  root := 'C:\';
  For ch := 'A' to 'Z' Do Begin
    root[1] := ch;
    Case GetDriveType( Pchar( root )) Of
      DRIVE_FIXED, DRIVE_REMOTE:
        If not ScanDrive( root, edit1.text, listbox1.items ) Then           Break;
    End;
  End;
end;
 
procedure TForm1.Button3Click(Sender: TObject);
begin // aborts scan
  fScanAborted := True;
end;
 
And as a bonus here is a function to search a file for a string:
 
Function ScanFile( Const filename: String;
                    Const forString: String;
                    caseSensitive: Boolean ): LongInt;
{ returns position of string in file or -1, if not found }
Const
  BufferSize= $8001;  { 32K+1 bytes }
Var
  pBuf, pEnd, pScan, pPos : Pchar;
  filesize: LongInt;
  bytesRemaining: LongInt;
  bytesToRead: Word;
  F    : File;
  SearchFor: Pchar;
  oldMode: Word;
Begin
  Result := -1;  { assume failure }
  If (Length( forString ) = 0) or (Length( filename ) = 0) Then Exit;   SearchFor := Nil;
  pBuf      := Nil;
 
  { open file as binary, 1 byte recordsize }
  AssignFile( F, filename );
  oldMode := FileMode;
  FileMode := 0;    { read-only access }
  Reset( F, 1 );
  FileMode := oldMode;
  try { allocate memory for buffer and pchar search string }
    SearchFor := StrAlloc( Length( forString )+1 );
    StrPCopy( SearchFor, forString );
    If not caseSensitive Then  { convert to upper case }
      AnsiUpper( SearchFor );
    GetMem( pBuf, BufferSize );
    filesize := System.Filesize( F );
    bytesRemaining := filesize;
    pPos := Nil;
    While bytesRemaining > 0 Do Begin
      { calc how many bytes to read this round }
      If bytesRemaining >= BufferSize Then
        bytesToRead := Pred( BufferSize )
      Else
        bytesToRead := bytesRemaining;
 
      { read a buffer full and zero-terminate the buffer }
      BlockRead( F, pBuf^, bytesToRead, bytesToRead );
      pEnd := @pBuf[ bytesToRead ];
      pEnd^:= #0;
      { scan the buffer. Problem: buffer may contain #0 chars! So we         treat it as a concatenation of zero-terminated strings. }       pScan := pBuf;
      While pScan < pEnd Do Begin
        If not caseSensitive Then { convert to upper case }
          AnsiUpper( pScan );
        pPos := StrPos( pScan, SearchFor );  { search for substring }         If pPos <> Nil Then Begin { Found it! }
          Result := FileSize - bytesRemaining +
                    LongInt( pPos ) - LongInt( pBuf );
          Break;
        End;
        pScan := StrEnd( pScan );
        Inc( pScan );
      End;
      If pPos <> Nil Then Break;
      bytesRemaining := bytesRemaining - bytesToRead;
      If bytesRemaining > 0 Then Begin
      { no luck in this buffers load. We need to handle the case of         the search string spanning two chunks of file now. We simply         go back a bit in the file and read from there, thus inspecting         some characters twice
      }
        Seek( F, FilePos(F)-Length( forString ));
        bytesRemaining := bytesRemaining + Length( forString );       End;
    End; { While }
  finally
    CloseFile( F );
    If SearchFor <> Nil Then StrDispose( SearchFor );
    If pBuf <> Nil Then FreeMem( pBuf, BufferSize );
  end;
end; { ScanFile }
0
 
LVL 9

Expert Comment

by:ITugay
ID: 2680170
Sample bellow is shown how to find substring in list of texts files.

legend:
(TEdit)  Edit1.Text - string to search
(TListBox) ListBox1 - list of files to search
(TListBox) ListBox2 - result of search, if string found then filename + position of string in text file will there.

-----------------
function SearchInFile(aFileName,aSearchStr : string) : integer;
var L : TStringList;
begin
  result:=0;
  L:=TStringList.Create;
  try
    L.LoadFromFile(aFileName);
    result:=pos(aSearchStr,L.Text);
  finally
    L.Free;
  end;
end;

procedure TForm1.SpeedButton1Click(Sender: TObject);
var I,N : integer;
begin
   ListBox2.Clear; // clear result
   for I:=0 to ListBox1.Items.Count-1 do // iterate all files
   begin
     N:=SearchInFile(ListBox1.Items[I],Edit1.Text); // search
     if N > 0 // put result
        then ListBox2.Items.Add(ListBox1.Items[I]+' '+IntToStr(N-1));
   end;
end;
--------

Cheers,
Igor
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