SEARCH KEYWORD -- FILE PERMISSION


  Save QWidget as image

Qt library is an excellent GUI library for C++ programmers developed by Nokia and now is an open source project. Often, we may use QPainter to draw strings, lines or images on a QWidget. We can override the QWidget's paintEvent() method when we want to use QPianter object to draw something on a QWidget. If we want to save the items drawn on QWidget as image for later reference, what can we do? We can save a QWidget as an image. Here is the code for achieving this: QPixmap pixmap(this->size())...

   Qt,C++,QWidget,Image     2012-08-19 12:01:18

  What is goroutine?

Casual Talk Golang is quite enjoyable to write, aside from the tedious if err != nil checks. One of the fundamental reasons for the joy is goroutine, a core feature of Golang. Understanding goroutines in detail is worthwhile, as they contribute significantly to the pleasure of working with Golang. So, let's talk about goroutines, hoping to provide some insights to the readers. TL;DR: We'll start by talking about assembling a computer, then delve into some concepts of the operating system, such ...

   EXPLANATION,GOLANG,GOROUTINE     2024-01-21 03:26:10

  OpenLDAP Proxy -- Introduction

OpenLDAP is an open source project which is intended to provide some commercial-grade, fully featured applications and development tools based on the well known Light-weight Directory Access Protocol(LDAP). Hence corporations which want to manage their user and group information can freely use these tools.  OpenLDAP provides ldap servers, ldap clients and corresponding tools to work on LDAP. The LDAP server is called slapd(Stand-alone LDAP  daemon). And it would serve as the server whi...

   META,OPENLDAP,OPENLDAP PROXY,SLAPD,SLAPD.CONF,LDAP     2017-10-28 11:20:00

  The hidden risk of passing slice as function parameter

In Go's source code or other open source libraries, there are lots of cases where a slice pointer is passed to function instead of slice itself. This brings up a doubt why not passing slice directly as its internal is backed by an array pointer to point to underlying data? For example, in log package, the formatHeader function takes a parameter buf as type *[]byte instead of []byte. func (l *Logger) formatHeader(buf *[]byte, t time.Time, file string, line int) {} Let's understand the r...

   GOLANG,SLICE,SLICE POINTER     2020-12-13 06:11:14

  Java Cipher encryption/decryption example

In Java, Cipher is the API for doing data encryption/decryption. Many cryptographic algorithms such as AES, DES, RC4 etc can be specified when creating Cipher instance. The Cipher instance calls the underlying algorithm specific implementation to do the actual encryption/decryption.  Before doing the encryption/decryption, a key needs to be created and it will be used to do the encryption/decryption. A sample program for performing all these is : import java.security.Key; import javax.cryp...

   Java, Java Security, Cipher, Example, Sample     2015-08-14 07:07:10

  Singleton Pattern in Golang

Singleton pattern is the simplest design pattern in software design. It ensures that only one instance of an object exists globally, regardless of how many times the object is instantiated. Based on the characteristics of the singleton pattern, it can be applied to scenarios such as global unique configuration, database connection objects, file access objects, etc. In Go language, there are multiple ways to implement the singleton pattern. Today, let's learn together about some of these approach...

   GOLANG,SINGLETON PATTERN,TUTORIAL     2023-08-18 23:52:05

  Python PLC Honeypot: Env Deployment And Attack Detection

In the previous article, we introduced the design of Python PLC Honeypot Project, this article will provide detailed step-by-step instructions on how to deploy and use the honeypot system in your environment for detecting potential attacks on OT (Operational Technology) networks. The article includes three main section:   Design of Attack Alert and Notification Function Honeypot deployment: an example deployment of a mixed OT protocol honeypot, consisting of a simple setup with...

       2024-12-01 00:27:33

  GCC is compiled with C++ compiler

On 15 Aug, 2012, GCC merged a patch--Merge from cxx-conversion branch . This means GCC will be compiled with C++ compiler in the future, it also means that GCC will be implemented using C++. You may have following two puzzles: Why does GCC turn to C++? Without C++ compiler, how can we compile C++ codes? Why using C++? In GNU's C++ Conversion, we can find this description in the background section: Whether we use C or C++, we need to try to ensure that interfaces are easy to understan...

   GCC,C++,Compiler     2012-09-04 02:36:06

  Processing Unicode Data in Python - A Primer to Understand Non-English Data Processing

Introduction: Currently we live in a world where people of diverse cultures/backgrounds use electronic devices to express their ideas, do their daily work that earns them their daily bread, and entertain themselves using content that is created using their own language and so on. Naturally, in order to make all these things happen, any computational instrument, be it a laptop or a desktop computer, or a smartphone, or something else, should be capable enough to serve all of these things in a man...

   PYTHON,UNICODE,UTF-8,NON-ENGLISH DATA,ASCII CODE     2019-04-10 00:55:19

  A mini guide to HTTP referer

In HTTP header, there is a field named Referer which is to provide the referrer of the current accessed page. In this post, we will introduce the usage of HTTP referer field. On the web, when a user visits a webpage, s/he must be from some place. This place is usually referred a s referer. This information is very important to some website operators and server owners as they want to know where they get the traffic from and this helps them provide better service for potential targeted users. In t...

   HTML,HTTP REFERER,REFERRERPOLICY     2019-06-29 02:23:25

RECENT