LQWiki - User contributions [en]

Talk:In the beginning was the command line

2004-03-12T03:57:19Z

MHouliston: reply to: subjective

subjective
[[User:Marcel|Marcel]] 22:32, Mar 11, 2004 (EST)
----

:You're probably right. I thought it was a great book, so I guess I haven't been impartial about it. Do you think it's worth keeping the link, if I take out my sycophantic enthusiasm? Or is the whole thing too far off-topic anyway?

:[[User:MHouliston|MHouliston]] 22:57, Mar 11, 2004 (EST)

Man page

2004-03-12T03:48:14Z

MHouliston: slight changes...I'll stop now :-)

'''Man pages''': ''manual pages''

Accessed using the [[man]] command.

Man pages are also referred to as the Unix Online Documentation (though they are not "online" in the modern sense). They contain information about proper syntax and options, and are the Unix equivalent of ''help files''. They are included on almost all Unix systems. There is a page for almost every [[command]], and for a number of [[Configuration File|configuration files]] as well.

Contents and quality vary between applications, but typically tend towards:

* being very thorough
* being succinct
* being more a reference rather than a tutorial

This means that you will frequently come across information in man pages that you do not yet understand. Don't worry about it; becoming a Linux guru is a gradual process. If you don't need the excess information right now, ignore it. Otherwise read it again, slowly. If it still makes no sense, look here in the LinuxQuestions.org wiki for an explanation. If it still makes no sense, go to an [[Getting_help_from_IRC|IRC]] chat or a web forum and explain you're having trouble understanding the man page. You'll always be treated sympathetically if you've tried to [[RTFM]].

See also

* [[man man]], [[RTFM]], [[documentation]]

Man page

2004-03-12T03:35:06Z

MHouliston: more changes against man...clearer now I think

'''Man pages''': ''manual pages''

Accessed using the [[man]] command.

Man pages are also referred to as the Unix Online Documentation (though they are not "online" in the modern sense). They are available for almost every [[command]], and for a number of [[Configuration File|configuration files]] as well. They are included on almost all Unix systems, and contain information about proper syntax and options. The contents and quality vary between applications, but typically tend towards:

* being very thorough
* being more a reference rather than a tutorial

This means that you will frequently come across information in man pages that you do not yet understand. Don't worry about it; becoming a Linux guru is a gradual process. If you don't need the excess information right now, ignore it. Otherwise read it again slowly. If it still makes no sense, look here in the LinuxQuestions.org wiki for an explanation. If it still makes no sense, go to an [[Getting_help_from_IRC|IRC]] chat or a web forum and explain you're having trouble making sense of the man page. You'll be treated sympathetically because you've made an attempt to [[RTFM]].

See also

* [[man man]], [[RTFM]], [[documentation]]

Man

2004-03-12T03:31:46Z

MHouliston: another slight rearrangement against man page

'''man''': ''access the [[man page]] for a given command''

Usage:

:<code>$ man locate</code>

Provided your man pages are working correctly, this will bring up detailed information about the [[locate]] program. Read <code>man [[updatedb]]</code> while you're about it.

Man pages are sometimes split into sections. On most systems the sections are numbered 1 to 8, representing these categories:

#General commands
#Low-level system calls
#C library functions
#Special files (usually devices, those found in /dev)
#File formats and conventions
#Games
#Miscellanea
#System administration and associated commands

To view a specific section, you type the appropriate number before the name of the page you wish to view. For example, section 1 (general commands) of the command [[ls]] would be referred to as:

:<code>$ man 1 ls</code>

===See also:===
*[[documentation]]
*[[man man]]
*[[TLDP]]

Documentation

2004-03-12T03:03:58Z

MHouliston: removed duplicate link

'''Documentation''' is one of the great features of the [[Linux]] community - there is a vast amount of it. Documentation describes any document which provides information about the configuration, running or general usage of an [[application]]. The Linux documentation generally comes in the form of [[man pages]] and [[Howto]] documents. These are easily obtainable from [[TLDP|The Linux Documentation Project]], [[Google]] or here at the LinuxQuestions.org wiki.

See also: [[FAQ]], [[commands]]

Man

2004-03-12T03:02:40Z

MHouliston: rewrite for clarity and disambiguation with man page

'''man''': ''access the [[man page]] for a given command''

Usage:

<code>man locate</code>

Provided your man pages are working correctly, this will bring up detailed information about the [[locate]] program (read <code>man [[updatedb]]</code> while you're about it).

Man pages are included on almost all Unix systems, and contain information about proper syntax and options. The contents and quality vary between applications, but typically tend towards:

* being very thorough
* being more a reference rather than a tutorial

This means that you will frequently come across information in man pages that you do not yet understand. Don't worry about it; becoming a Linux guru is a gradual process. If you don't need the excess information right now, ignore it. Otherwise read it again slowly. If it still makes no sense, look here in the LinuxQuestions.org wiki for an explanation. If it still makes no sense, go to an [[Getting_help_from_IRC|IRC]] chat or a web forum and explain you're having trouble making sense of the man page. You'll be treated sympathetically because at least you made an attempt to [[RTFM]].

===See also:===
[[documentation]], [[TLDP]]

Man page

2004-03-12T02:54:10Z

MHouliston: formatting; link fixes

'''Man pages''': ''manual pages''

Also known as the Unix Online Documentation (though it's not "online" in the modern sense). Man pages are available for almost every [[command]], and for a number of [[Configuration File|configuration files]] as well.

Accessed using the [[man]] command.

See also

* [[man man]], [[RTFM]], [[documentation]]

Man page

2004-03-12T02:51:32Z

MHouliston: rewrite for clarity and disambiguation with man

'''Man pages''': ''manual pages''

Also known as the Unix Online Documentation (though it's not "online" in the modern sense). Man pages are available for almost every command, and for quite a few [[configuration files]] as well.

Accessed using the [[man]] command.

See also

* [[man man]], [[RTFM]], [[documentation]]

Manual page

2004-03-12T02:31:44Z

MHouliston: adjusted redirect

#REDIRECT [[man page]]

Ncurses

2004-03-12T02:18:36Z

MHouliston: s/program's/programs

When you run a command line program, usually it's the sort where lines of text scroll up the screen, perhaps stopping for you to enter some input -- all on a line-by-line basis. These sorts of programs are said to have a [[command line interface]]. You run them from a [[terminal]] or terminal window.

Other terminal programs present to you a sort of text-based text-only [[GUI]] that takes place right there in the terminal. Programs like [[vim]] and [[lynx]] do this. When run, these programs take over the terminal's display, and use all width x height elements to create a sort of textual blocky GUI. Usually, this feat is accomplished using the ncurses library.

Ncurses-based programs tend to be fairly easy to use, and very fast.

LQWiki talk:How to use a redirect

2004-03-12T02:16:54Z

MHouliston: maybe add this too?

Might also be worth mentioning how to fix redirects after you've just unthinkingly pointed them at the wrong url ;-)

I use the link: http://wiki.linuxquestions.org/wiki.phtml?title=REDIRECT_PAGE_NAME&redirect=no

[[User:MHouliston|MHouliston]] 21:16, Mar 11, 2004 (EST)
----

Locate

2004-03-12T02:04:01Z

MHouliston: added "see also" links

The '''locate''' command will return all files and directories that contain the search string in its name. It is basically equivalent to using

<code>find / -name *expression*</code>

Except that it is much faster.
It does this by querying the locate database which is updated periodically by the system. The following illustration demonstrates the output of the locate command:

<code>prompt:$ locate passwd 
/etc/init.d/rpasswdd 
/etc/pam.d/passwd 
/etc/pam.d/rpasswd 
/etc/passwd 
/etc/passwd.old 
/etc/samba/smbpasswd </code>

The locate database can be defined by changing the value of the LOCATE_PATH environment variable. The database is typically updated daily. If you wish to force an update use the updatedb or "locate -u" command.

You can use regular expressions with locate through the -r flag:

<code>locate -r "core\.[0-9]"</code>

returns:

<code>/usr/share/man/man4/pcmcia_core.4.gz 
/usr/share/man/man2/mincore.2.gz</code>

(It will also find core.[pid] files, which is handy.)

===See also:===
*[[updatedb]]
*[[find]]
*[[which]]

Linux installation

2004-03-12T02:03:20Z

MHouliston: added links

==Foreword==
As installation varies so much, you are best advised to look at the details for your chosen distribution.

Some [[Live CD distributions]], such as [[Knoppix]] allow you to test-drive before you install, and have a very good automatic detection and configuration system.

Most distributions autodetect your hardware, although [[WiFi]] is still a sticking point.

A [[Source_distributions|source based distribution]] such as [[Gentoo]] encourages people to get to grips with Linux by making you configure, compile and set up everything from scratch. It's really worth doing if you have the time to learn that way, and the learning method and quality of the documentation set it apart from most other distros.

==System requirements==

There are hardly default hardware requirements. It depends a lot on the used [[Distributions|distribution]] and how much you are willing to tweak it. Most Linux [[distributions]] are rather modest with their hardware requirements so running any of them on a modern computer will not pose any problems. 
 
Of course if you require to run Linux on a pre Pentium machine you might get in trouble using the latest [[Mandrake]], [[Fedora]], etc. because they may not support every processor type and require a certain amount of system memory. 
 
On the other hand using the latest technology may confront you with a lack of drivers and propper support. 
 
A happy medium is probably the best solution.

==Choosing a distribution==
===How to decide which distribution to use?===

'''Always use the same [[distribution]] as the [[guru]] next door!''' This way you have somebody around to question and ask for help. 
 
In general if you don't need special features or have exotic hardware requirements and little or no [[Linux]] knowledge you are on the safe side using one of the major [[distributions]], i.e. [[Fedora]], [[Mandrake]], [[Suse]], [[Red_Hat]]. All them are equipped with a graphical installation, preconfigured desktop and graphical configuration tools. 
 
If you just want to try [[Linux]] your best choice is one of the [[Live_CD_distributions | Live CD distributions]] which run from one CD and don't need to be installed at all. 
 
Special hardware requirements and/or curiosity may lead you to other [[distributions]] like [[VectorLinux]] for sparse hardware which is based on [[Slackware]]... 
 
Probably every [[distribution]] would be worth mentioning but believe me as I said before: '''The best [[distribution]] is the one your personal [[guru]] has!'''

===Distribution specific guides===
A comprehensive list of [[Distributions]].
===How to get them?===

* Buy a boxed [[Distributions|distribution]] online or in a store. This way you get user guides specific for your distribution and support from the distributor.
* Download the [[ISO]] files and burn your own CD set. The ISO files can be found at the main [[Distributions|distribution]] site or on countless mirrors.
* Download only a small installation CD and install your system directly per [[FTP Install]] or [[HTTP Install]]. Only the selected software is downloaded which is in most cases faster than downloading the whole CD set. But not every [[Distributions|distribution]] supports this installation type.
* Sometimes magazines add partial or even complete [[distributions]].

==Configuring your new Linux==
* [[Networking]]
* [[Security]]
* [[Hardware]]

==What next? How to make the most of your new Linux.==
* List of Linux [[Applications]]
* List of Linux [[Commands]]
* [[Common Tasks]]
* [[Documentation]]
* [[Gaming]]

==External links==
(links to guides etc.)

GCC

2004-03-12T01:59:08Z

MHouliston: added "see also" links

The GNU Compiler Collection.

http://www.gnu.org/directory/gcc.html
contains a [[compiler]] for the most popular languages: [[c]], [[c_plus_plus|c++]], [[objective-c]], [[java]], and [[fortran 77]]. By default it installs front-ends for all of the languages, however, if you only want to install some of the front-ends use the configure option:

<tt>--with-languages=languages</tt>.

===See also:===
*[[ld]]
*[[Library-related Commands and Files]]

Compiler

2004-03-12T01:51:44Z

MHouliston: link added

A '''compiler''' is a [[program]] that translates human-readable [[source code]] into machine-readable binary code. In some [[programming languages]] like [[java]], after a program is compiled it still requires an [[interpreter]] in order to execute the code. Usually, though, the compiled code will run on its own. In Linux, this is [[ELF]] format for modern binaries (replacing the older a.out format) - in Windows it's EXE.

See also: [[assembly]], [[linker]], [[GCC]], [[Compilation From Source]]

Scripts

2004-03-12T01:42:03Z

MHouliston: added some links

'''Scripts''' are small [[programs]] that don't need to be [[compiled]], often written in languages such as [[Perl]], [[PHP]], [[JavaScript]], etc.

See also: [[Shell scripts]]

Getting help from IRC

2004-03-12T01:36:10Z

MHouliston: added some links

Most major distributions will have a user-supported channel on the IRC network FreeNode (Formerly OpenProjects). in order to connect to an IRC network you will need an [[IRC Client]].
----
Here are some of the channels for some of the more major distributions (in alphabetical order):

* '''[[Debian]]''' - #Debian
* '''[[Fedora]]''' - #fedora
* '''[[Gentoo]]''' - #Gentoo
* '''[[Mandrake]]''' - #Mandrake
* '''[[Slackware]]''' - #slackware
----

For help getting started with IRC, see [[Using IRC]].

===See also:===
[[documentation]], [[linux books]]

In the beginning was the command line

2004-03-12T01:26:12Z

MHouliston: initial entry

'''In the beginning was the command line''': excellent essay about the history of computing, by [[hacker]] novelist Neal Stephenson. Written in 1999, it's still relevant today, and should be read by everyone with an interest or involvement in computers. Print it out and take it with you on your next train, plane or bus journey. You'll be glad you did.

===External links:===

*[http://www.cryptonomicon.com/beginning.html Full text of "In the beginning was the command line"]

===See also:===

* [[command line]], [[history]], [[linux books]]

Command-line interface

2004-03-12T00:50:28Z

MHouliston: #redirect command line

#redirect [[command line]]

DOSBox

2004-03-09T20:18:57Z

MHouliston:

#redirect[[Dosbox]]

DOSBox

2004-03-09T20:18:37Z

MHouliston: #redirectDOSBox

#redirect[[DOSBox]]

DOS

2004-03-09T20:17:54Z

MHouliston: lnx

1:'''DOS''': ''[[Denial of Service]] attack''

2:'''DOS''': ''Disk Operating System''

'Disk Operating System' applies to any of a number of systems, the most widely-known of which is MS-DOS, the independently marketed version of PC-DOS (which was distributed with IBM personal computers). It was derived from QDOS (the Quick and Dirty Operating System) which, in turn, was based on CP/M. PC-DOS, as developed by Microsoft and released by IBM in 1981, was a very simple 16-bit operating system without the concept of directories or any of a number of other features commonly considered essential to an operating system. Beginning with PC-DOS 2.0, some of these features were added. With DOS 6.22, the 16-bit line (with Windows 3x and under being a separate application) came to an end and DOS 7, a 32-bit extension with Windows 4x more tightly integrated, was introduced as Windows 95. That line came to an end with Windows ME, being superseded by Windows NT, which had been developed in parallel since 1993. NT is not DOS, and merely emulates it in order to continue to run some DOS applications. An open source clone, [http://www.freedos.org FreeDOS] exists, bearing a similar relationship to MS-DOS as Linux does to UNIX. FreeDOS is also what drives DOS applications under [[DOSEMU]] on Linux systems, by default.

See also: [[DOSBox]]

C Programming Language

2004-03-09T20:05:49Z

MHouliston: #redirectC

#redirect[[C]]

OS X

2004-03-09T19:48:17Z

MHouliston: #redirect Mac OS X

#redirect [[Mac OS X]]

DOSEMU

2004-03-09T19:43:25Z

MHouliston: added links

[http://www.dosemu.org/ DOSEMU] is an intermediary between Linux and [[FreeDOS]], or other [[DOS]] systems, which enable DOS programs - from old games to business applications - to run under Linux, both from the terminal and, in [[X Window System|X]], in a [[Terminal Emulator|terminal emulator]] (not to be confused with OS [[Emulation|emulators]]).

Installation can be as simple as unpacking the DOSEMU binaries and the FreeDOS system and tweaking a config file. While not all applications work perfectly, it probably enjoys a higher success rate than Windows emulators, since it handles a simpler system.

See also the X-only(SDL) and more gaming-oriented [[Dosbox]].

FreeDOS

2004-03-09T19:42:19Z

MHouliston: some elaboration

'''FreeDOS''': ''Free, MS-DOS compatible operating system''

The FreeDOS project was founded in 1994 by Jim Hall.

See also: [[DOS]], [[DOSEMU]]

External links:
*http://www.freedos.org/

FreeDOS

2004-03-09T19:35:51Z

MHouliston: initial entry

FreeDOS:

External links:
*http://www.freedos.org/

OSDL

2004-03-09T19:23:30Z

MHouliston: formatting fixes

'''OSDL''': ''Open Source Development Labs''

A not-for-profit consortium of technology companies which aims to accelerate the widepsread adoption of [[Linux]]. Members include [[IBM]], [[HP]], [[Novell]], [[Intel]], [[SUN | Sun]], [[SuSe]], [[Red Hat]] and [[Cisco]].

'''See also:''' [[Linus Torvalds]], [[GNU]]

'''External link:''' [http://www.osdl.org OSDL Official website]

OSDL

2004-03-09T19:20:03Z

MHouliston: added some links

'''OSDL''': ''Open Source Development Labs''

A not-for-profit consortium of technology companies which aims to accelerate the widepsread adoption of [[Linux]].

Members include [[IBM]], [[HP]], [[Novell]], [[Intel]], [[SUN | Sun]], [[SuSe]], [[Red Hat]] and [[Cisco]].

See also: [[Linus Torvalds]], [[GNU]]

==External link==

* [http://www.osdl.org OSDL.org] - Official website

Kernel

2004-03-09T19:18:10Z

MHouliston: added some links

The '''Kernel''' is the core of the [[operating system]]. It is a single [[program]] (or sometimes a group of them) that manages the interaction of all other programs on a computer system, and the available resources of that system (like [[RAM]] or [[disk]] space).

A kernel can be thought of as a telephone switch-board - it routes calls from place to place. It has no interest in what those calls are about, only that everyone who dials a number gets connected with the person they're calling. The kernel must make sure that no program gets either too little or too much of the system's attention.

Some example kernels:
* The [[Linux]] kernel, developed by [[Linus Torvalds]] and contributors world-wide. The [[history]] of Linux goes back over a decade.
* The [[HURD]], the [[GNU]] project's (as yet unfinished) kernel.
* [[Mach]], a ''microkernel'' used by operating systems such as Apple's OS X.

Some important components of a kernel:
* [[Virtual Memory]] support
* [[Multitasking]]
* [[Context Switching]]
* [[Device Drivers]]

See also: [[Compiling a Kernel]], [[Dmesg]]

Bridging made easy

2004-03-09T19:14:00Z

MHouliston: link typo

This page covers how to set up a simple bridge acting as both an ethernet [[switch]] and endpoint. This is probably the most common way to set up bridging in a small home or office [[network]]. Let's start with what is needed.

We'll need:
* a RedHat system or some derivative using /etc/sysconfig/network-scripts
* a system with two or more network cards
* a [[Linux Kernel]] supporting bridging via [[kernel module]] (<tt>bridge.o</tt>) or [[compiled-in driver]]
* the brctl command, comes with the <tt>bridge-utils</tt> RPM or can be downloaded from http://bridge.sourceforge.net/

After having checked these prerequisites identify the <tt>ethx</tt> names of the ethernet [[interfaces]] that will comprise the bridge. Let's say we have a scenario where <tt>eth0</tt> is our external interface and <tt>eth1</tt> and <tt>eth2</tt> will be our internal bridge. First, "null" these interfaces by editing their respective configuration files in /etc/sysconfig/network-scripts:

ifcfg-eth1
<pre>
DEVICE=eth1
BOOTPROTO=none
ONBOOT=yes
</pre>

ifcfg-eth2
<pre>
DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
</pre>

The interfaces will now get "empty" adresses on boot. Now let's edit the bridge interface:

ifcfg-br0
<pre>
brctl addbr br0 2&> /dev/null
brctl addif br0 eth1 2&> /dev/null
brctl addif br0 eth2 2&> /dev/null
brctl stp br0 off 2&> /dev/null
DEVICE=br0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
</pre>

Now just run <tt>/etc/rc.d/init.d/network restart</tt> to bring up your bridge, and reconfigure filtering and [[routing]] scripts to act on the interface "br0" instead of what you had there earlier.

It's actually that simple. If you have more interfaces just list them after <tt>brctl addif br0 eth2</tt>. The redirect to /dev/null is because this is actually an ugly hack and as such will spew some errors when the network is restarted or stopped. The command <tt>brctl stp br0 off</tt> disables spanning tree protocol because we only need the simple switching functions of the bridge in this case.

See also: [[Advanced Networking]], [[TCP/IP]], [[LAN]]

Bridging made easy

2004-03-09T19:11:50Z

MHouliston: added some links

GPL

2004-03-09T18:57:40Z

MHouliston: extra links

The '''GPL''', or ''General Public License'', is a [[software]] license designed to enforce the rights of the software user, rather than furthering the rights of the software author at the end-user's expense. It is the standard license of the [[GNU]] project, and much of the important software in a [[Linux]] system is licensed using the GPL.

Whereas many software licenses place restrictions on the end-user's use of the software, the GPL places restrictions on the author's use. GPL-licensed software must be available in [[source code]] form, and the rights of the GPL must be assigned to anyone who uses the package or modifies it. Because this tendency flies in the face of traditional copyright considerations, this legal arrangement is sometimes referred to as [[copyleft]].

A related license called the [[LGPL]] also exists.

See also: [[free]], [[open source]]

External links:
* [http://www.gnu.org/copyleft/gpl.html Text of the GNU GPL]

Compile

2004-03-09T18:48:39Z

MHouliston: fixed links

'''Compile''': ''the act of converting human-readable [[source code]] into machine-readable code''

Usually carried out by a [[compiler]]. Compilation is generally not (easily) reversible, so [[recompiling]] is a familiar task to many [[users]].

See also: [[GCC]], [[make]], [[programming languages]]

 
''This article is a [[LinuxQuestions.org_Wiki:stub_articles|stub]] and needs to be finished. [[LinuxQuestions.org_Wiki:plunging_forward|Plunge forward]] and [[LinuxQuestions.org_Wiki:How_to_edit_a_page|help it grow]] !''

Recompile

2004-03-09T18:46:22Z

MHouliston: changed to redirect to compile

#redirect [[compile]]

Recompile

2004-03-09T18:45:41Z

MHouliston: initial entry

'''Recompile''': ''[[compile]] again''

Compile

2004-03-09T18:44:47Z

MHouliston: initial entry

'''Compile''': ''the act of converting human-readable [[source code]] into machine-readable code''

Usually carried out by a compiler. Compilation is generally not (easily) reversible, so [[recompiling]] is a familiar task to many [[users]].

See also: [[GCC]], [[make]], [[Linker]]

 
''This article is a [[LinuxQuestions.org_Wiki:stub_articles|stub]] and needs to be finished. [[LinuxQuestions.org_Wiki:plunging_forward|Plunge forward]] and [[LinuxQuestions.org_Wiki:How_to_edit_a_page|help it grow]] !''

Documentation

2004-03-09T17:39:58Z

MHouliston: typo...when will I learn to preview?

'''Documentation''' is one of the great features of the [[Linux]] community - there is a vast amount of it. Documentation describes any document which provides information about the configuration, running or general usage of an [[application]]. The [[Linux]] documentation generally comes in the form of [[man pages]] and [[Howto]] documents. These are easily obtainable from [[TLDP|The Linux Documentation Project]], [[Google]] or here at the LinuxQuestions.org wiki.

See also: [[FAQ]], [[commands]]

Documentation

2004-03-09T17:39:11Z

MHouliston: sowed some links

'''Documentation''' is one of the great features of the [[Linux]] community - there is a vast amount of it. Documentation describes any document which provides information about the configuration, running or general usage of an [[application]]. The [[Linux]] documentation generally comes in the form of [[man pages]] and [[Howto]] documents. These are easily obtainable from [TLDP| The Linux Documentation Project], [[Google]] or here at the LinuxQuestions.org wiki.

See also: [[FAQ]], [[commands]]

Software

2004-03-09T17:32:46Z

MHouliston: added note about documentation

One or many [[programs]], usually with associated [[documentation]].

See also: [[applications]], [[open source]]

Programs

2004-03-09T17:23:56Z

MHouliston: adjusted to give better sense of "applications"

A '''computer program''' is a sequence of instructions that is understandable by a [[computer]]. Generally, it indicates which operations the computer should perform on a set of data. Usually it will be stored for reuse in one or many [[files]]. Complex programs (or ''applications'') may be made from many smaller programs working together, though [[unix philosophy]] generally favours the adoption of small, terse programs that are responsible for fairly specific tasks.

Many thousands of programs may exist on a computer, and many programs may run at the same time. If the computer [[hardware]] and OS are capable of [[multi-tasking]], and the program in question is sufficiently carefully written, many instances of one program may run at one time. Computer [[operating systems]] themselves constitute a collection of programs decided by the [[manufacturer]], [[distributor]] or [[administrator]].

The [[source code]] for programs is written in one or more [[programming languages]]. Some programs need to be [[compiled]] (or in the case of [[assembly language]], assembled) before they can be interpreted by a [[processor]]. Those which do not need to be compiled (because they are interpreted by processes already running on the computer) are referred to as [[scripts]].

See also: [[applications]], [[open source]], [[compiler]], [[process]]

Alpha

2004-03-09T17:11:09Z

MHouliston: sowed some links

1) The '''[[DEC]] Alpha''' microprocessor.

See also: [[processor]], [[platform]]

2) '''Alpha software''': very early release of [[software]]. Alpha releases of a program are generally very unstable and are meant for testing purposes only, not general usage. The intent of an alpha release is to receive bug reports from the general user-base, not just the regular developers and testers.

See also: [[beta]], [[open source]]

Programming languages

2004-03-09T17:02:41Z

MHouliston: #redirect programming language

#redirect [[programming language]]

Compiler

2004-03-09T17:01:35Z

MHouliston: sowed some links

Software

2004-03-09T16:48:30Z

MHouliston: initial entry

One or many [[programs]].

See also: [[applications]], [[programming language]], [[open source]]

Unix philosophy

2004-03-09T16:44:00Z

MHouliston: initial entry

I cannot express [[Unix]] philosophy better than those who invented it:

From Doug McIlroy, the man who invented [[piping]]
:''This is the Unix philosophy: Write programs that do one thing and do it well. Write programs to work together. Write programs to handle text streams, because that is a universal interface.""

From Rob Pike, one of the greatest [[C]] programmers ever:

*''Rule 1. You can't tell where a program is going to spend its time. Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is.''

*''Rule 2. Measure. Don't tune for speed until you've measured, and even then don't unless one part of the code overwhelms the rest.''

*''Rule 3. Fancy algorithms are slow when n is small, and n is usually small. Fancy algorithms have big constants. Until you know that n is frequently going to be big, don't get fancy. (Even if n does get big, use Rule 2 first.)''

*''Rule 4. Fancy algorithms are buggier than simple ones, and they're much harder to implement. Use simple algorithms as well as simple data structures.''

*''Rule 5. Data dominates. If you've chosen the right data structures and organized things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming.[9]''

*''Rule 6. There is no Rule 6.''

From Ken Thompson, who designed and implemented the first Unix
*''When in doubt, use brute force.''

See also: [[History]], [[operating system]], [[programming]]

Program

2004-03-09T16:35:47Z

MHouliston: #redirect programs

#redirect [[programs]]

Programs

2004-03-09T16:35:07Z

MHouliston: initial

A '''computer program''' (or ''application'') is a sequence of instructions that is understandable by a [[computer]]. Generally, it indicates which operations the computer should perform on a set of data. Usually it will be stored for reuse in one or many [[files]]. Complex programs may be made from many smaller programs working together, though [[unix philosophy]] generally favours the adoption of small, terse programs that are responsible for fairly specific tasks.

Many thousands of programs may exist on a computer, and many programs may run at the same time. If the computer [[hardware]] and OS are capable of [[multi-tasking]], and the program in question is sufficiently carefully written, many instances of one program may run at one time. Computer [[operating systems]] themselves constitute a collection of programs decided by the [[manufacturer]], [[distributor]] or [[administrator]].

The [[source code]] for programs is written in one or more [[programming languages]]. Some programs need to be [[compiled]] (or in the case of [[assembly language]], assembled) before they can be interpreted by a [[processor]]. Those which do not need to be compiled (because they are interpreted by processes already running on the computer) are referred to as [[scripts]].

See also: [[applications]], [[open source]], [[compiler]], [[process]]

Application

2004-03-09T16:34:54Z

MHouliston: link to program

An '''Application''' is basically any computer [[program]]. It normally serves a specific function and (hopefully) lives up to that task. [[Linux]] has a very rich collection of [[Applications]]

Programming language

2004-03-09T15:40:16Z

MHouliston: initial

'''Programming language'''

Programming languages are used to write [[programs]], which are a means of issuing instructions to and receiving data from [[computers]]. Programming languages are characterised by highly rigid syntactic laws and a limited (though not necessarily small) vocabulary of [[commands]] that may be used. While each programming language has its own syntax and vocabulary, some are more closely related than others. However, they all serve the same purpose of abstracting from the low level [[machine code]] that computer processors require.

Here is a small list of commonly used programming languages:

*Algol
*Basic
*C
*Delphi
*Eiffel
*Fortran
*Java
*Lisp
*Perl
*Ruby
*SmallTalk
*Visual Basic

 
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See also: [[script]], [[compiler]], [[oop]]