一些字符串处理函数

// Get the Position of a string, starting at the end
function LastPos(SearchStr, Str: string): Integer;
var
    i: Integer;
    TempStr: string;
begin
    Result := Pos(SearchStr, Str);
    if Result = 0 then
        Exit;
    if (Length(Str) > 0) and (Length(SearchStr) > 0) then
    begin
        for i := Length(Str) + Length(SearchStr) - 1 downto Result do
        begin
            TempStr := Copy(Str, i, Length(Str));
            if Pos(SearchStr, TempStr) > 0 then
            begin
                Result := i;
                break;
            end;
        end;
    end;
end;

function LastPos(SubStr, S: string): Integer;
var
    Found, Len, Pos: Integer;
begin
    Pos := Length(S);
    Len := Length(SubStr);
    Found := 0;
    while (Pos > 0) and (Found = 0) do
    begin
        if Copy(S, Pos, Len) = SubStr then
            Found := Pos;
        Dec(Pos);
    end;
    LastPos := Found;
end;

// Search for the next occurence of a string from a certain Position
function NextPos(SearchStr, Str: string; Position: Integer): Integer;
begin
    Delete(Str, 1, Position - 1);
    Result := Pos(SearchStr, upperCase(Str));
    if Result = 0 then
        Exit;
    if (Length(Str) > 0) and (Length(SearchStr) > 0) then
        Result := Result + Position + 1;
end;

// Get the number of characters from a certain Position to the string to be searched
function NextPosRel(SearchStr, Str: string; Position: Integer): Integer;
begin
    Delete(Str, 1, Position - 1);
    Result := Pos(SearchStr, upperCase(Str)) - 1;
end;

// simple replacement for strings
function ReplaceStr(Str, SearchStr, ReplaceStr: string): string;
begin
    while Pos(SearchStr, Str) <> 0 do
    begin
        Insert(ReplaceStr, Str, Pos(SearchStr, Str));
        Delete(Str, Pos(SearchStr, Str), Length(SearchStr));
    end;
    Result := Str;
end;