Server Side Programming Articles - Page 2297 of 2651

In this section we will see how to execute zombie process and orphan process in a single program in C/C++. Before going to the main discussion, let us see what are the zombie process and orphan process.Zombie ProcessesA zombie process is a process whose execution is completed but it still has an entry in the process table. Zombie processes usually occur for child processes, as the parent process still needs to read its child’s exit status. Once this is done using the wait system call, the zombie process is eliminated from the process table. This is known as reaping the ... Read More

In this section, you will learn how to use SQLite in C/C++ programs.InstallationBefore you start using SQLite in our C/C++ programs, you need to make sure that you have SQLite library set up on the machine. You can check the SQLite Installation chapter to understand the installation process.C/C++ Interface APIsFollowing are important C/C++ SQLite interface routines, which can suffice your requirement to work with SQLite database from your C/C++ program. If you are looking for a more sophisticated application, then you can look into SQLite official documentation.Serial NoAPI & Description1sqlite3_open(const char *filename, sqlite3 **ppDb)This routine opens a connection to an ... Read More

In C++, virtual and pure virtual functions are key features supporting polymorphism both allow different classes to respond uniquely to the same function call. What is Virtual Function A virtual function in C++ is a member function in a base class, which allows a function to be overridden in the derived class. This process helps in enabling runtime polymorphism. A virtual function is declared in the base class using the virtual keyword. Syntax Following is the syntax of the virtual function: class BaseClassName { public: virtual void func_name() { // implementation ... Read More

An lvalue (locator value) represents an object that occupies some identifiable location in memory (i.e. has an address).rvalues are defined by exclusion. Every expression is either an lvalue or an rvalue, so, an rvalue is an expression that does not represent an object occupying some identifiable location in memory.For example, An assignment expects an lvalue as its left operand, so the following is valid:int i = 10; But this is not: int i; 10 = i;This is because i has an address in memory and is a lvalue. While 10 doesn't have an identifiable memory location and hence is an ... Read More

A pure virtual function is a function that has no implementation in the base class and must be overridden by any derived class. It is declared using = 0 in the base class. Pure Virtual Destructor When we want the base class to be abstract then we declare a pure virtual Destructor. A pure virtual Destructor can be declared in C++ after a destructor has been created as a pure virtual object. One of the most important things is that if a class contains a pure virtual destructor, it must provide a function body for the pure virtual destructor. ... Read More

In this section we will see what is the fork system call in C. This fork system call is used to create a new process. This newly created process is known as child process. The current process which is creating another child process is called the parent process.A child process uses the same program counter, CPU register, same files that are used by the parent process.The fork() does not take any parameter, it returns integer values. It may return three types of integer values.Negative Number: It returns negative number when child process creation is failedZero Value: It returns Zero for ... Read More

What is an Assertions in C/C++? An assertion is a statement used to test assumptions made by the program. When an assertion fails, the program displays an error and stops. This is mainly used for debugging. In C and C++, assertions are handled using the assert() macro defined in the (C) or (C++) header file. Following is the declaration for assert() Macro. #include // in C // or #include in C++ assert(expression); The parameter of this assert() is expression: This can be a variable or any C/C++ expression. If ... Read More

Multithreading is a specialized form of multitasking and a multitasking is the feature that allows your computer to run two or more programs concurrently. In general, there are two types of multitasking: process-based and thread-based.Process-based multitasking handles the concurrent execution of programs. Thread-based multitasking deals with the concurrent execution of pieces of the same program.A multithreaded program contains two or more parts that can run concurrently. Each part of such a program is called a thread, and each thread defines a separate path of execution.C does not contain any built-in support for multithreaded applications. Instead, it relies entirely upon the ... Read More

In C/C++, we use the header files for accessing functions such as int, char, string, etc. The printf() function of C is also a built-in function that is declared in the "stdio.h" header file and it is used to print any kind of data on the console. C to Print "Hello World" without Header Files The Hello World is the given string that is used in the printf() to get the output. Make sure you don't have any headers to print the result. So, use an argument like (const char *text, ...) that solves the problem. Syntax Below is the ... Read More

In this section we will see how to execute the if and else section simultaneously in a C or C++ code. This solution is little bit tricky.When the if and else are executed one after another then it is like executing statements where if-else are not present. But here we will see if they are present how to execute them one after another.Example Code#include using namespace std; int main() {    int x = 10;    if(x > 5)   {       lebel_1: cout