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diff --git a/src/frontend_blog/articles/scrap1_U.2.html b/src/frontend_blog/articles/scrap1_U.2.html new file mode 100644 index 00000000..059b4417 --- /dev/null +++ b/src/frontend_blog/articles/scrap1_U.2.html @@ -0,0 +1,219 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd"> +<html> +<!-- This is the second edition of Free Software, Free Society: Selected Essays of Richard M. Stallman. + +Free Software Foundation + +51 Franklin Street, Fifth Floor + +Boston, MA 02110-1335 +Copyright C 2002, 2010 Free Software Foundation, Inc. +Verbatim copying and distribution of this entire book are permitted +worldwide, without royalty, in any medium, provided this notice is +preserved. Permission is granted to copy and distribute translations +of this book from the original English into another language provided +the translation has been approved by the Free Software Foundation and +the copyright notice and this permission notice are preserved on all +copies. + +ISBN 978-0-9831592-0-9 +Cover design by Rob Myers. + +Cover photograph by Peter Hinely. + --> +<!-- Created on February 18, 2016 by texi2html 1.82 +texi2html was written by: + Lionel Cons <Lionel.Cons@cern.ch> (original author) + Karl Berry <karl@freefriends.org> + Olaf Bachmann <obachman@mathematik.uni-kl.de> + and many others. +Maintained by: Many creative people. +Send bugs and suggestions to <texi2html-bug@nongnu.org> +--> +<head> +<title>Free Software, Free Society, 2nd ed.: Appendix A: A Note on Software</title> + +<meta name="description" content="This is the second edition of Richard Stallman's collection of essays."> +<meta name="keywords" content="Free Software, Free Society, 2nd ed.: Appendix A: A Note on Software"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="texi2html 1.82"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +pre.display {font-family: serif} +pre.format {font-family: serif} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: serif; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: serif; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.roman {font-family:serif; font-weight:normal;} +span.sansserif {font-family:sans-serif; font-weight:normal;} +ul.toc {list-style: none} +--> +</style> +<link rel="stylesheet" type="text/css" href="../style.css"> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> + +<a name="Appendix-A"></a> +<header><div id="logo"><img src="../gnu.svg" height="100" width="100"></div><h1>Free Software, Free Society, 2nd ed.</h1></header><section id="main"><a name="Appendix-A_003a-A-Note-on-Software"></a> +<h1 class="unnumbered"> <span class="roman">Appendix A: A Note on Software</span> </h1> + +<p>Written by Richard E. Buckman and Joshua Gay. +<br> +</p> +<p>This section is intended for people who have little or no knowledge of +the technical aspects of computer science. It is not necessary to read +this section to understand the essays and speeches presented in this +book; however, it may be helpful to those readers not familiar with +some of the jargon that comes with programming and computer science. +</p> +<p>A computer <em>programmer</em> writes software, or computer programs. A +program is more or less a recipe with <em>commands</em> to tell the +computer what to do in order to carry out certain tasks. You are more +than likely familiar with many different programs: your Web browser, +your word processor, your email client, and the like. +</p> +<p>A program usually starts out as <em>source code</em>. This higher-level +set of commands is written in a <em>programming language</em> such as C +or Java. After that, a tool known as a <em>compiler</em> translates this +to a lower-level language known as <em>assembly language</em>. Another +tool known as an <em>assembler</em> breaks the assembly code down to the +final stage of <em>machine language</em>—the lowest level—which the +computer understands <em>natively</em>. +</p> +<img src="code.jpg" alt="code"> + +<p>For example, consider the +“hello world” program, a common first program for people learning C, +which (when compiled and executed) prints “Hello World!” on the screen. +<a name="DOCF54" href="#FOOT54">(54)</a> +</p> +<table><tr><td> </td><td><pre class="smallexample">int main(){ + printf(''Hello World!''); + return 0; +} +</pre></td></tr></table> + +<p>In the Java programming language the same program would +be written like this: +</p> +<table><tr><td> </td><td><pre class="smallexample">public class hello { + public static void main(String args[]) { + System.out.println(''Hello World!''); + } +} +</pre></td></tr></table> + +<p>However, in machine language, a small section of it may look similar to +this: +</p> +<table><tr><td> </td><td><pre class="smallexample">1100011110111010100101001001001010101110 +0110101010011000001111001011010101111101 +0100111111111110010110110000000010100100 +0100100001100101011011000110110001101111 +0010000001010111011011110111001001101100 +0110010000100001010000100110111101101111 +</pre></td></tr></table> + +<p>The above form of machine language is the most basic representation +known as binary. All data in computers is made up of a series of +0-or-1 values, but a person would have much difficulty understanding +the data. To make a simple change to the binary, one would have to +have an intimate knowledge of how a particular computer interprets the +machine language. This could be feasible for small programs like the +above examples, but any interesting program would involve an +exhausting effort to make simple changes. +</p> +<p>As an example, imagine that we wanted to make a change to our “Hello +World” program written in C so that instead of printing “Hello World” +in English it prints it in French. The change would be simple; here is +the new program: +</p> +<table><tr><td> </td><td><pre class="smallexample">int main() { + printf(''Bonjour, monde!''); + return 0; +} +</pre></td></tr></table> + +<p>It is safe to say that one can easily infer how to change the program +written in the Java programming language in the same way. However, +even many programmers would not know where to begin if they wanted to +change the binary representation. When we say “source code,” we do +not mean machine language that only computers can understand—we are +speaking of higher-level languages such as C and Java. A few other +popular programming languages are C++, Perl, and Python. Some are +harder than others to understand and program in, but they are all much +easier to work with compared to the intricate machine language +they get turned into after the programs are compiled and assembled. +</p> +<p>Another important concept is understanding what an <em>operating +system</em> is. An operating system is the software that handles input and +output, memory allocation, and task scheduling. Generally one +considers common or useful programs such as the <em>Graphical User +Interface</em> (GUI) to be a part of the operating system. The GNU/Linux +operating system contains a both GNU and non-GNU software, and a +<em>kernel</em> called <em>Linux</em>. The kernel handles low-level tasks +that applications depend upon such as input/output and task +scheduling. The GNU software comprises much of the rest of the +operating system, including GCC, a general-purpose compiler for many +languages; GNU Emacs, an extensible text editor with many, many +features; GNOME, the GNU desktop; GNU libc, a library that all +programs other than the kernel must use in order to communicate with +the kernel; and Bash, the GNU command interpreter that reads your +command lines. Many of these programs were pioneered by Richard +Stallman early on in the GNU Project and come with any modern +GNU/Linux operating system. +</p> +<p>It is important to understand that even if <em>you</em> cannot +change the source code for a given program, or directly use all these +tools, it is relatively easy to find someone who can. Therefore, by +having the source code to a program you are usually given the power to +change, fix, customize, and learn about a program—this is a power that +you do not have if you are not given the source code. Source +code is one of the requirements that makes a piece of software +<em>free</em>. The other requirements will be found along with the +philosophy and ideas behind them in this collection. +</p><div class="footnote"> +<hr> +<h3>Footnotes</h3> +<h3><a name="FOOT54" href="#DOCF54">(54)</a></h3> +<p>In other programming languages, such as +Scheme, the <em>Hello World</em> program is usually not your first program. +In Scheme you often start with a program like this: +</p><table><tr><td> </td><td><pre class="smallexample">(define (factorial n) + (if (= n 0) + 1 + (* n (factorial (- n 1))))) +</pre></td></tr></table> + +<p>This computes the factorial of a number; that is, running +<code>(factorial 5)</code>would output 120, which is computed by doing +5 * 4 * 3 * 2 * 1 * 1. +</p></div> +<hr size="2"> +<table cellpadding="1" cellspacing="1" border="0"> +<tr><td valign="middle" align="left">[<a href="scrap1_43.html#Freedom-or-Power" title="Previous section in reading order"> < </a>]</td> +<td valign="middle" align="left">[<a href="scrap1_U.3.html#Appendix-B" title="Next section in reading order"> > </a>]</td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left">[Contents]</td> +<td valign="middle" align="left">[<a href="scrap1_U.4.html#Index" title="Index">Index</a>]</td> +<td valign="middle" align="left">[<a href="scrap1_abt.html#SEC_About" title="About (help)"> ? </a>]</td> +</tr></table> +<p> + <font size="-1"> + This document was generated by <em>Christian Grothoff</em> on <em>February 18, 2016</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.82</em></a>. + </font> + <br> + +</p> +</body> +</html> |