1.Introduction to C programming Language.
C was the direct successor of B, a stripped down version of BCPL, created by Ken Thompson at Bell Labs, that was also a compiled language - User's Reference to B, used in early internal versions of the UNIX operating system. As noted in Ritchie's C History : "The B compiler on the PDP-7 did not generate machine instructions, but instead 'threaded code', an interpretive scheme in which the compiler's output consists of a sequence of addresses of code fragments that perform the elementary operations. The operations typically — in particular for B — act on a simple stack machine". Thompson and Dennis Ritchie, also working at Bell Labs, improved B and called the result NB. Further extensions to NB created its logical successor, C. Most of UNIX was rewritten in NB, and then C, which resulted in a more portable operating system.
The portability of UNIX was the main reason for the initial popularity of both UNIX and C. Rather than creating a new operating system for each new machine, system programmers could simply write the few system-dependent parts required for the machine, and then write a C compiler for the new system. Since most of the system utilities were thus written in C, it simply made sense to also write new utilities in C.The American National Standards Institute began work on standardizing the C language in 1983, and completed the standard in 1989. The standard, ANSI X3.159-1989 "Programming Language C", served as the basis for all implementations of C compilers. The standards were later updated in 1990 and 1999, allowing for features that were either in common use, or were appearing in C++.
The minimum software requirements to program in C is a text editor, as opposed to a word processor. A plain text Notepad Editor can be used but it does not offer any advanced capabilities such as code completion or debugging. There are many text editors (see List of Text Editors), among the most popular are Notepad++ for Windows, Sublime Text, Vim and Emacs are also available cross-platform. These text editors come with syntax highlighting and line numbers, which makes code easier to read at a glance, and to spot syntax errors.
Though not absolutely needed, many programmers prefer and recommend using an Integrated development environment (IDE) instead of a text editor. An IDE is a suite of programs that developers need, combined into one convenient package, usually with a graphical user interface. These programs include a text editor, linker, project management and sometimes bundled with a compiler. They also typically include a debugger, a tool that will preserve your C source code after compilation and enable you to do such things as step through it manually, or alter data as an aid to finding and correcting programming errors.
For beginners it is recommended not to use an IDE, since it hides most of what is going on. Using the command line builds up familiarity with the toolchain. An IDE may be useful to somebody with programming experience but knows how the IDE works. So as a general guideline: Do not use an IDE unless you know what the IDE does!