Monday, October 30, 2017

C - Program Structure

Before we study the basic building blocks of the C programming language, let us look at a bare minimum C program structure so that we can take it as a reference in the upcoming chapters.

Hello World Example

A C program basically consists of the following parts −
  • Preprocessor Commands
  • Functions
  • Variables
  • Statements & Expressions
  • Comments
Let us look at a simple code that would print the words "Hello World" −

 

Let us take a look at the various parts of the above program −
  • The first line of the program #include <stdio.h> is a preprocessor command, which tells a C compiler to include stdio.h file before going to actual compilation.
  • The next line int main() is the main function where the program execution begins.
  • The next line /*...*/ will be ignored by the compiler and it has been put to add additional comments in the program. So such lines are called comments in the program.
  • The next line printf(...) is another function available in C which causes the message "Hello, World!" to be displayed on the screen.
  • The next line return 0; terminates the main() function and returns the value 0.

Compile and Execute C Program

Let us see how to save the source code in a file, and how to compile and run it. Following are the simple steps −
  • Open a text editor and add the above-mentioned code.
  • Save the file as hello.c
  • Open a command prompt and go to the directory where you have saved the file.
  • Type gcc hello.c and press enter to compile your code.
  • If there are no errors in your code, the command prompt will take you to the next line and would generate a.out executable file.
  • Now, type a.out to execute your program.
  • You will see the output "Hello World" printed on the screen.
$ gcc hello.c
$ ./a.out
Hello, World!
Make sure the gcc compiler is in your path and that you are running it in the directory containing the source file hello.c.


Sunday, October 22, 2017

C - Environment Setup



Local Environment Setup

If you want to set up your environment for C programming language, you need the following two software tools available on your computer, (a) Text Editor and (b) The C Compiler.

Text Editor

This will be used to type your program. Examples of few a editors include Windows Notepad, OS Edit command, Brief, Epsilon, EMACS, and vim or vi.
The name and version of text editors can vary on different operating systems. For example, Notepad will be used on Windows, and vim or vi can be used on windows as well as on Linux or UNIX.
The files you create with your editor are called the source files and they contain the program source codes. The source files for C programs are typically named with the extension ".c".
Before starting your programming, make sure you have one text editor in place and you have enough experience to write a computer program, save it in a file, compile it and finally execute it.

The C Compiler

The source code written in source file is the human readable source for your program. It needs to be "compiled", into machine language so that your CPU can actually execute the program as per the instructions given.
The compiler compiles the source codes into final executable programs. The most frequently used and free available compiler is the GNU C/C++ compiler, otherwise you can have compilers either from HP or Solaris if you have the respective operating systems.
The following section explains how to install GNU C/C++ compiler on various OS. We keep mentioning C/C++ together because GNU gcc compiler works for both C and C++ programming languages.

Installation on UNIX/Linux

If you are using Linux or UNIX, then check whether GCC is installed on your system by entering the following command from the command line −
$ gcc -v
If you have GNU compiler installed on your machine, then it should print a message as follows −
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr .......
Thread model: posix
gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)
If GCC is not installed, then you will have to install it yourself using the detailed instructions available at http://gcc.gnu.org/install/
This tutorial has been written based on Linux and all the given examples have been compiled on the Cent OS flavor of the Linux system.

Installation on Mac OS

If you use Mac OS X, the easiest way to obtain GCC is to download the Xcode development environment from Apple's web site and follow the simple installation instructions. Once you have Xcode setup, you will be able to use GNU compiler for C/C++.
Xcode is currently available at developer.apple.com/technologies/tools/.

Installation on Windows

To install GCC on Windows, you need to install MinGW. To install MinGW, go to the MinGW homepage, www.mingw.org, and follow the link to the MinGW download page. Download the latest version of the MinGW installation program, which should be named MinGW-<version>.exe.
While installing Min GW, at a minimum, you must install gcc-core, gcc-g++, binutils, and the MinGW runtime, but you may wish to install more.
Add the bin subdirectory of your MinGW installation to your PATH environment variable, so that you can specify these tools on the command line by their simple names.
After the installation is complete, you will be able to run gcc, g++, ar, ranlib, dlltool, and several other GNU tools from the Windows command line.

Thursday, October 19, 2017

1st day of programming



                                C Tutorial

C is a general-purpose, procedural, imperative computer programming language developed in 1972 by Dennis M. Ritchie at the Bell Telephone Laboratories to develop the UNIX operating system. C is the most widely used computer language. It keeps fluctuating at number one scale of popularity along with Java programming language, which is also equally popular and most widely used among modern software programmers.

Audience

This tutorial is designed for software programmers with a need to understand the C programming language starting from scratch. This tutorial will give you enough understanding on C programming language from where you can take yourself to higher level of expertise.

Prerequisites

Before proceeding with this tutorial, you should have a basic understanding of Computer Programming terminologies. A basic understanding of any of the programming languages will help you in understanding the C programming concepts and move fast on the learning track.

 

Execute C Online

For most of the examples given in this tutorial you will find Try it option, so just make use of this option to execute your C programs at the spot and enjoy your learning.
Try following example using Try it option available at the top right corner of the below sample code box −





C is a general-purpose, high-level language that was originally developed by Dennis M. Ritchie to develop the UNIX operating system at Bell Labs. C was originally first implemented on the DEC PDP-11 computer in 1972.
In 1978, Brian Kernighan and Dennis Ritchie produced the first publicly available description of C, now known as the K&R standard.
The UNIX operating system, the C compiler, and essentially all UNIX application programs have been written in C. C has now become a widely used professional language for various reasons −
  • Easy to learn
  • Structured language
  • It produces efficient programs
  • It can handle low-level activities
  • It can be compiled on a variety of computer platforms

Facts about C

  • C was invented to write an operating system called UNIX.
  • C is a successor of B language which was introduced around the early 1970s.
  • The language was formalized in 1988 by the American National Standard Institute (ANSI).
  • The UNIX OS was totally written in C.
  • Today C is the most widely used and popular System Programming Language.
  • Most of the state-of-the-art software have been implemented using C.
  • Today's most popular Linux OS and RDBMS MySQL have been written in C.

Why use C?

C was initially used for system development work, particularly the programs that make-up the operating system. C was adopted as a system development language because it produces code that runs nearly as fast as the code written in assembly language. Some examples of the use of C might be −
  • Operating Systems
  • Language Compilers
  • Assemblers
  • Text Editors
  • Print Spoolers
  • Network Drivers
  • Modern Programs
  • Databases
  • Language Interpreters
  • Utilities

C Programs

A C program can vary from 3 lines to millions of lines and it should be written into one or more text files with extension ".c"; for example, hello.c. You can use "vi", "vim" or any other text editor to write your C program into a file.
This tutorial assumes that you know how to edit a text file and how to write source code inside a program file.
















Tuesday, October 10, 2017

First Program


C – Programming Basics


If you are looking for C programs,
This C programming basics section explains a simple “Hello World” C program. Also, it covers below basic topics as well, which are to be known by any C programmer before writing a C program.
  1. C programming basic commands to write a C program
  2. A simple C program with output and explanation
  3. Steps to write C programs and get the output
  4. Creation, Compilation and Execution of a C program
    * How to install C compiler and IDE tool to run C programming codes
  5. Basic structure of a C program
    * Example C program to compare all the sections
    * Description for each section of the C program
  6. C programs ( Click here for more C programs ) with definition and output – C program for Prime number, Factorial, Fibonacci series, Palindrome, Swapping 2 numbers with and without temp variable, sample calculator program and sample bank application program etc.

1. C programming basics to write a C Program:

Below are few commands and syntax used in C programming to write a simple C program. Let’s see all the sections of a simple C program line by line.
C Basic commands Explanation
#include <stdio.h> This is a preprocessor command that includes standard input output header file(stdio.h) from the C library before compiling a C program
int main() This is the main function from where execution of any C program begins.
{ This indicates the beginning of the main function.
/*_some_comments_*/ whatever is given inside the command “/*   */” in any C program, won’t be considered for compilation and execution.
printf(“Hello_World! “); printf command prints the output onto the screen.
getch(); This command waits for any character input from keyboard.
return 0;
This command terminates C program (main function) and returns 0.
}
This indicates the end of the main function.

2. A simple C Program:

Below C program is a very simple and basic program in C programming language. This C program displays “Hello World!” in the output window. And, all syntax and commands in C programming are case sensitive. Also, each statement should be ended with semicolon (;) which is a statement terminator.

Output:

Hello World!

C programming reference book ...

Books are very important for learning and practice the process of all things. So before starting C programing Language we Suggest some books for better learning.

For BANGLA : 

https://drive.google.com/file/d/0B1ADgAB1pSDTbkVkNGMwTktvVTA/view
For English:
https://mega.nz/#!JFowGZ6Y!vHZwDLXLq90F5IcFgtH4hIx1fmektLRm1GDnhLTitKk

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