1.0 Introduction

We need passwords to login to our accounts. These password must be unbreakable. One way to make a password strong is to make it random. Here is a program in C language which can be used to generate a random password offline.… Read more

1.0 Structures

A structure is a collection of variables for an entity. The variables are known as members of the structure and are located at consecutive memory locations. The size of the structure is the sum of sizes of the members plus any padding that might be placed by the system.… Read more

1.0 Introduction

A pointer variable holds the address of another variable. It is said to be "pointing" to that variable. For example,

int *ip;

defines a variable ip of type integer pointer. ip points to a variable of type integer. At the implementation level, it holds the address of a variable to type integer.… Read more

1.0 Introduction

A C program comprises of global data and functions. A program must have a main function and the execution starts at the first statement in the main function. A function has local data and statements. The control flow deals with the order in which statements are executed by a program.… Read more

1.0 Introduction

Data is an important part of a program. In fact, programs are written so that data can be captured, processed, stored and presented to the user. The success of a program depends on how well data has been organized and used.… Read more

1.0 I/O multiplexing

I/O multiplexing is the the ability to perform I/O operations on multiple file descriptors. Input operations like read, accept and calls for receiving messages block when there is no incoming data. So, if an input call is made and it blocks, we may miss data from other file descriptors.… Read more

1.0 Temporary Files

Quite often, we need temporary files in our programs. Some intermediate data needs to be stored and the file can be discarded when the process terminates. There are functions and command to create temporary files in Linux. The mkstemp function creates a temporary file and returns a file descriptor.… Read more

1.0 Unix Domain Sockets

A socket is a communication endpoint at a host computer. The socket API provides calls for communication between processes. The socket system call is,

int socket (int domain, int type, int protocol);

The first parameter to the socket system call is the domain.… Read more