program LogFinder;
{$mode objfpc}{$H+} // Use Object Pascal mode and Ansistrings (dynamic strings)
uses
Classes, SysUtils, StrUtils;
// Type definition for a dynamic array of strings
type
TStringArray = array of string;
{ Find all log lines with a given date }
function FindAllLogsByDate(const Logs: string; const TargetDate: string): TStringArray;
var
Lines: TStringArray;
Matches: TStringArray;
Line: string;
MatchCount: Integer;
begin
MatchCount := 0;
SetLength(Matches, 0);
{ Split the big string by newline characters, mimicking std::getline loop.
We handle both \n (Linux/macOS) and \r\n (Windows) by splitting on \n
and trimming if necessary. }
Lines := SplitString(Logs, #10);
for Line in Lines do
begin
{ Pos returns > 0 if the substring is found, equivalent to != std::string::npos }
if Pos(TargetDate, Line) > 0 then
begin
Inc(MatchCount);
SetLength(Matches, MatchCount);
// Remove any leftover carriage returns (#13) from Windows line endings
Matches[MatchCount - 1] := TrimRight(Line);
end;
end;
Result := Matches;
end;
var
Logs: string;
Results: TStringArray;
R: string;
begin
// Multi-line string concatenation using regular string literals
Logs :=
'01/12/2023 - Log entry one.' + #10 +
'17/03/2021 - Log entry two.' + #10 +
'29/07/2019 - Log entry three.' + #10 +
'05/11/2024 - Log entry four.' + #10 +
'22/08/2020 - Log entry five.' + #10 +
'14/02/2018 - Log entry six.' + #10 +
'30/09/2022 - Log entry seven.' + #10 +
'11/06/2017 - Log entry eight.' + #10 +
'03/04/2025 - Log entry nine.' + #10 +
'05/11/2024 - Log entry ten.';
Results := FindAllLogsByDate(Logs, '05/11/2024');
// For-in loop to iterate through the results (requires FPC 2.4.2+)
for R in Results do
begin
WriteLn(R);
end;
end.
(*
run:
05/11/2024 - Log entry four.
05/11/2024 - Log entry ten.
*)
