<!doctype linuxdoc system> <article> <title>Programming Languages mini-HOWTO </title> <author>Risto S. Varanka </author> <date>Jul 22nd 2000 </date> <abstract>A brief comparison of major programming languages for Linux and major libraries for creating graphical user interfaces (GUIs) under Linux </abstract> <toc> <sect>Introduction <p>Linux is a fascinating operating system because it lets any user participate in its development. The variety of available languages, however, can be confusing to beginning Linux developers. This document lists the most common options for everyday development and states some key facts about them. (Well, ``most common'' and ``key'' as I perceive them.)</p> <!-- point to possible larger howto --> <p>My aim is neither to review the languages nor to determine which one is the best. Each language is a tool that fits some jobs and some tastes. You can get further (often conflicting) information easily, if you ask around or keep your ears open. The Links sections in this document will give you some pointers for your own research.</p> <!-- perhaps there should be some freeform discussion in the Comments part of the tables --> <!-- why is my language not included? perhaps explain that in detail --> <p>There is a plethora of languages and libraries for Linux, so this document only covers the most common languages and GUI (Graphical User Interface) toolkits at the moment. This document is intended to be fairly neutral, but I haven't included all languages available. Since my judgment is undoubtedly biased in many ways, I advise serious developers to check out the sites that do a better job in listing all languages and libraries. Also note that only the Linux implementations of the languages and GUI toolkits are covered, their features on other platforms are not discussed or implied.</p> <p>This document is a recent addition to the LDP, so there has not been opportunity for much community feedback. However, it is released in hopes that it will prove useful for people interested in programming under Linux, especially beginners. A question mark in the tables indicates lack of information. If you can fill it in, please contact the author. </p> <sect1>Latest Version of the Document <p>You can find the latest modifications at <url url="http://www.helsinki.fi/~rvaranka/Computer/Linux/HOWTO/" name="http://www.helsinki.fi/~rvaranka/Computer/Linux/HOWTO/"></p> <sect1>Copyright <p>Copyright (c) 2000 Risto Varanka.</p> <sect1>License <p>The following license terms apply to all LDP documents, unless otherwise stated in the document. The LDP documents may be reproduced and distributed in whole or in part, in any medium physical or electronic, provided that this license notice is displayed in the reproduction. Commercial redistribution is permitted and encouraged. Thirty days advance notice via email to the author(s) of redistribution is appreciated, to give the authors time to provide updated documents. </p> <sect2>Requirements of Modified Works <p>All modified documents, including translations, anthologies, and partial documents, must meet the following requirements:</p> <p> <enum> <item>The modified version must be labeled as such. <item>The person making the modifications must be identified. <item>Acknowledgement of the original author must be retained. <item>The location of the original unmodified document be identified. <item>The original author's (or authors') name(s) may not be used to assert or imply endorsement of the resulting document without the original author's (or authors') permission. </enum> </p> <p>In addition it is requested that:</p> <p> <enum> <item>The modifications (including deletions) be noted. <item>The author be notified by email of the modification in advance of redistribution, if an email address is provided in the document. </enum> </p> <p>As a special exception, anthologies of LDP documents may include a single copy of these license terms in a conspicuous location within the anthology and replace other copies of this license with a reference to the single copy of the license without the document being considered ``modified'' for the purposes of this section.</p> <p>Mere aggregation of LDP documents with other documents or programs on the same media shall not cause this license to apply to those other works. </p> <p>All translations, derivative documents, or modified documents that incorporate any LDP document may not have more restrictive license terms than these, except that you may require distributors to make the resulting document available in source format.</p> <sect1>Disclaimer <p>THIS DOCUMENT COVERS A LARGE AND CONSTANTLY CHANGING DOMAIN. THEREFORE, THE INFORMATION CONTAINED IN THIS DOCUMENT MAY BE INCORRECT OR OUTDATED. ALL USE OF THIS DOCUMENT AND ALL INFORMATION CONTAINED IN IT IS AT YOUR OWN RISK. THE AUTHOR DOES NOT GIVE ANY WARRANTY OR GUARANTEE, EITHER EXPLICIT OR IMPLIED. </p> <sect1>Author <p>You are welcome to send feedback to the author at: <url url="mailto:risto.varanka@helsinki.fi" name="risto.varanka@helsinki.fi">.</p> <p>Author's web site can be found at <url url="http://www.helsinki.fi/~rvaranka/" name="http://www.helsinki.fi/~rvaranka/">.</p> <sect1>Credits <p>I am thankful to several people who commented on language issues. These conversations have given me a better view of the different languages, and I hope future conversations will allow this mini-HOWTO to mature over time. Especially I would like to thank the people at the IRCNet channel #linux: Morphy, Bluesmurf, Vadim, Zonk^, Rikkus and others whose names I have forgotten. Thanks go also to Stig Erik Sandoe for helpful comments.</p> <sect1>Links <p>Exhaustive lists of Linux development libraries and tools:</p> <p> <itemize> <item><url url="http://www.freshmeat.net/appindex/development/" name="Freshmeat"> <item><url url="http://www.hotfeet.ch/~gemi/LDT/" name="Linux Development Tools"> <item><url url="http://www.linuxprogramming.com/" name="linuxprogramming.com"> </itemize> </p> <p>The <url url="http://www.tuxedo.org/~esr/faqs/hacker-howto.html" name="Hacker FAQ"> by Eric S. Raymond is another interesting text for novice Linux developers. It concentrates on some cultural and psychological aspects of open source development. </p> <p>Other <url url="http://www.linuxdoc.org/" name="LDP documents"> covering general programming subjects include the Reading List HOWTO and the Linux Programmer's Guide - several more have been written on specific subjects.</p> <sect>Programming Languages <!-- explain concept? --> <p>C, Lisp and Perl are traditional hacking languages in the GNU/Linux culture; Python, PHP, Java and C++ have gained new ground recently.</p> <sect1>Concepts in the Table <p> <descrip> <tag>Language</tag> A common name of the language. <tag>Beginner</tag> Indicates how well suited the language is for people with little programming experience. A language marked with ``yes'' should be viable for a beginner's first programming language. <tag>Performance</tag> How fast your applications are likely to run when you put them into production use. Performance depends more on your algorithmic programming skills than the actual language. As a rule of thumb, C, C++ and Fortran are sometimes necessary because they can offer better performance than other languages - at other times they might be unwieldy for the desired purpose. (One idea for unscientific ``benchmarking'' of the languages would be to implement a simple sorting algorithm in all of them and compare running times. This of course does not measure the performance of the actual language - since that concept does not make sense - but only the implementation. Of course it's also not a very reliable or thorough method, but it would give an example how running times in different languages can differ. Anybody want to help me with this?) <tag>OOP, Object-Oriented Programming vs. other paradigms</tag> Object-oriented programming is an important programming paradigm that is gaining popularity. In object oriented programming, data structures and algorithms are integrated into units, often called classes. OOP is often contrasted with procedural programming (which uses separate algorithms and data structures). It is not strictly dependent on language: you can do OOP in languages not listed as such (C for example), and program in the procedural style in languages that are listed as OOP. I've listed as OOP languages that have special features or add-ons to facilitate OOP. Functional languages (Lisp for example) are a bit different breed - among other things, functional programming is a superset of OOP. Logic programming (Prolog), also called declarative programming, on the other hand, is not related to the other types of programming in a similar sense. <tag>RAD, Rapid Application Development</tag> More dependent on the tools you are using than the actual language. There is a HOWTO on GUI development tools for Linux, although it's out of date. With a good graphical tool you can do RAD. RAD can be powerful when based on code reuse as well, so free software could provide a good starting point. <tag>Examples</tag> Mentions fields of programming the language is most often used in. Other good (and bad) uses exist, but they are less typical. <!-- explain categories in a future version --> <tag>Comments</tag> Additional information on the language, like capacities and dialects. </descrip> </p> <!-- Check case of languages: UPPER or Capital? --> <sect1>Major Languages <p> <verb> Perl Beginner: Yes - OOP: Yes Examples: Scripting, sysadmin, www Comments: Powerful for handling text and strings Python Beginner: Yes - OOP: Yes Examples: Scripting, application scripting, www Comments: TCL Beginner: Yes - OOP: No Examples: Scripting, sysadmin, applications Comments: PHP Beginner: Yes - OOP: Yes Examples: Www Comments: Popular for web databases Java Beginner: Yes - OOP: Yes Examples: Cross-platform applications, www Comments: Spreading to new areas, eg. e-commerce infrastructure Lisp Beginner: Yes - OOP: Functional Examples: Emacs modes (for Elisp), AI Comments: Variants Elisp, Clisp and Scheme Fortran Beginner: No - OOP: No Examples: Mathematical (scientific) applications Comments: Variants f77 and f90/95 C Beginner: No - OOP: No Examples: System programming, applications Comments: C++ Beginner: No - OOP: Yes Examples: Applications Comments: </verb> </p> <!-- is Prolog really major? Prolog Beginner: Yes? - OOP: Declarative Examples: Databases, AI Comments: --> <sect1>Shell Programming <p>Shells are an important programming environment, too. I haven't covered them because I don't understand the field very thoroughly yet. Knowledge of shells is important for anyone who works on Linux regularly, more so for system administrators. There are similarities between shell programming and other kinds of scripting - often they can achieve the same goals, and you have the option of choosing between native shell and a separate scripting language. Among the most popular shells are bash, tcsh, csh, ksh and zsh. You can get basic information on your shell with the <em>man</em> command, <em>man bash</em> for example.</p> <sect1>Other Languages <p>Other languages of note: AWK, SED, Smalltalk, Eiffel, Ada, Prolog, assembler, Objective C, Logo, Pascal (p2c converter)</p> <sect1>Links <!-- integrate these in the "table" perhaps --> <p> <itemize> <item><url url="http://www.tunes.org/Review/Languages.html" name="A general info site"> on programming languages, lots of info and opinions <item><url url="http://dev.scriptics.com/" name="TCL"> <item><url url="http://www.perl.org/" name="Perl"> <item><url url="http://www.python.org/" name="Python"> <item><url url="http://www.php.net" name="PHP"> <item><url url="http://www.javasoft.com/" name="Java"> <item><url url="http://clisp.cons.org/~haible/packages-clisp.html" name="clisp"> </itemize> </p> <sect>GUI Toolkits <p>The standard graphical subsystem for UNIX and Linux, called X, has its own libraries for GUI development. They provide a low-level programming interface to X, but tend to be hard to use. Old end-user applications and other toolkits of course make good use of them. Nowadays the Linux GUI scene is dominated by GTK+ and Qt, since two popular, complete user environments - GNOME and KDE - are based on them.</p> <!-- Explain concept? --> <sect1>Concepts in the Table <p> <descrip> <tag>Library</tag> Common name or abbreviation of the toolkit. <tag>Beginner</tag> Whether the toolkit is suitable for a newbie programmer. <tag>License</tag> Different licenses for different GUI toolkits have practical significance. GTK+, TK and GNUstep licenses allow you to develop both open source and closed source applications without paying for a license. Motif license requires payment, while the QT license requires payment only if you write closed source programs. <!-- refer to freedom as in free speech, check validity --> <tag>Language</tag> The language that is most often used with the toolkit. <tag>Bindings</tag> Other languages which can use the toolkit. <tag>Examples</tag> Applications that use the toolkit. <tag>Comments</tag> Additional information on the toolkit. </descrip> </p> <sect1>Major GUI Toolkits <!-- Change to the other format? Would be good since could include more info on WINGS and the GNUstep project. --> <p> <table> <tabular ca="llllll">Library|Beginner|License|Language|Bindings |Examples|Comments@ TK| Yes| Free| TCL| Perl, Python, others| make xconfig, TKDesk| @ GTK+| No| Free (LGPL)| C| Perl, C++, Python, many others| GNOME, Gimp| Very popular@ QT| No| Free for open source| C++| Python, Perl, C, others?| KDE| Very popular@ Motif| No| Non-free| C/C++| Python, others?| Netscape, Wordperfect| <url url="http://www.lesstif.org/" name="Lesstif"> is a free replacement@ GNUstep| No| Free (LGPL)| Objective C| Guile, Java?| None widely known, but see the <url url="http://www.gnustep.org/resources/apps.html" name="application list">| GNUstep is still under development@ </tabular> </table> </p> <p></p> <sect1>Links <p> <itemize> <item><url url="http://dev.scriptics.com/" name="TK"> <item><url url="http://www.gtk.org/" name="GTK+"> <item><url url="http://www.troll.no/" name="QT"> <item><url url="http://www.metrolink.com/" name="Motif"> <item><url url="http://www.gnustep.org/" name="GNUstep"> </itemize> </p> </article>