LQWiki - User contributions [en]

Sendmail

2004-03-15T19:46:14Z

Muir:

'''Sendmail''' is the name of a venerable MTA (or Mail Transfer Agent) still used today on the Internet at large. It is renowned for its arcane configuration files and history of security holes, although modern sendmail has taken great pains to overcome this reputation.

Sendmail understands the [[SMTP]] protocol, and others; it does not support reading mail (as a [[POP3]] or [[IMAP]] server does). Many enhancements to sendmail exist, for such things as anti-virus scanning in real time, anti-spam blacklist checking, and organization-wide mail routing. Most of these are implemented though the mail filter [[milter]].

All [[Linux]] systems typically come with sendmail, or a compatible program, and the major Unix MTAs such as [[qmail]] and [[postfix]] come with binaries that do "sendmail emulation", allowing them to function as drop-in replacements for sendmail.

* [http://www.sendmail.org/ sendmail.org], home of the Sendmail Consortium

Compile a kernel

2004-03-08T04:20:51Z

Muir: added: you need the compile too chain installed

== How to Compile a [[Kernel]] ==

First and foremost, [http://www.linux-sxs.org/upgrading/migration26.html THIS] may pertain to you so read that first and then you can proceed and [http://thomer.com/linux/migrate-to-2.6.html here] is a similar site. Both links are for those migrating to a 2.6 series kernel.

=== Obtaining and installing the Kernel Source ===

==== Getting the kernel source ====
To compile a kernel, you will need the kernel source. You can get it from [http://www.kernel.org kernel.org]. Your distribution may also already come with the kernel source, somewhere on the cd. 

==== Installing the kernel source ====
You can install the kernel source by either installing the package that came with your distribution, or extracting the [[tarball]] you downloaded from kernel.org .

1. Change Directory To /usr/src
cd /usr/src

2. Check for symlink (ex. /usr/src/linux->/usr/src/linux-2.4.18)
ls -alc

3. Double check with this command (output ex.) linux: symbolic link to linux-2.4.18-14
file linux

4. Remove the symlink
rm linux

5. Unpack the tarball (new kernel)
tar -zxvf linux-x.x.x.tar.gz
tar -jxvf linux-x.x.x.tar.bz2

6. Make a new link to the new kernel
ln -s /usr/src/linux-x.x.x /usr/src/linux

7. Type this to change to the directory
cd linux

=== Installing the tool chain and header files needed to compile ===

Not all (any?) Linux distributions come with all of the components needed to build a kernel. You'll need a C compiler, make, and system header files installed before you can begin to build the kernel.

=== Now Comes The Fun Part~! (compiling) ===

We will now compile the kernel. 

First, clean up anything we don't need, like the current .config and other files
make mrproper

Do this is if you want to use your old configuration from the 2.4 kernel with the 2.6 kernel: 
cp /usr/src/linux-2.4.x/.config /usr/src/linux

Now you configure your kernel using any one of these commands, whichever you like best: 
----
Basic config from terminal, a long list of questions you answer
make config
----
For ncurses GUI in the terminal
make menuconfig
----
For X-based GUI with modular explanations (QT Based)
make xconfig
----
Same as above, but for 2.6.x kernel only (GTK Based, and might be still buggy)
make gconfig

----

Note:
Don't forget to add module support and kernel support for future hardware.
Do not compile your hard drive and file system type as a module.
The configure program enables you to specify an enormous number of features. It is advisable to skim through all the sections to get a feel for the different things you can do. Most options are about specifying whether you want a feature [*] compiled into the kernel image, [M] compiled as a module, or [ ] not compiled at all. You can also turn off module support altogether from Loadable module support -->. The kernel configuration is one LINUX program that offers lots of help--select < Help > on any feature. The raw help file is /usr/src/linux/Documentation/Configure.help can be also worth reading.
When you're done with the config, click exit and save current configuration. Your file is now known as .config .

------->SKIP THE FOLLOWING IF DOING A 2.6.x KERNEL<------

make dep
"Ensures dependancies such as include files are in place"

(vi, pico, emacs) Makefile
"Want A Unique Kernel Name? Edit /usr/src/linux/Makefile and change EXTRAVERSION"

make clean
"To clean your sources so they compile correctly"

------>START HERE IF COMPILING A 2.6.x KERNEL<------

make bzImage
"To make the kernel image (compile and creates compressed image of kernel)"

make modules
"Compile your selected modules"

make modules_install
"To install newly compile modules (installs to /lib/modules/linux.x.x.x)"

=== Now It's Time To Install Your New Kernel~! ===

Remove the following links:
rm -rf /boot/System.map
rm -rf /boot/vmlinuz

Then copy the newly created kernel and system.map to /boot
cp /usr/src/linux/arch/i386/boot/bzImage /boot/vmlinuz-x.x.x
cp /usr/src/linux/System.map /boot/System.map-x.x.x

Make the new links:
ln -s /boot/vmlinuz-x.x.x /boot/vmlinuz
ln -s /boot/System.map-x.x.x /boot/System.map

Next, if present, remove existing initrd.img file:
rm -rf /boot/initrd.x.x.x.img

And create the new one:
/sbin/mkinitrd /boot/initrd-x.x.x.img x.x.x
(Note: )
The last set of x.x.x is the eqivalent to your new kernel version and it looks to /lib/modules for that version.

--------------------------------------------------------------------
Use The Steps That Pertain To You 
If You Use Grub Then Edit grub.conf 
If You Use Lilo Then Edit lilo.conf 
--------------------------------------------------------------------
remember to leave the entry to your old kernel image just in case,
so modify what is in the config originally to point to the old image
and make a new entry for you new image you just made ....
--------------------------------------------------------------------

<-> And Finally Edit Your /etc/grub.conf file <->
<-> Note some distros now use menu.lst, so if you can't find grub or lilo, then you know what to look for <->

title New Kernel :D
kernel /vmlinuz-x.x.x ro root=LABEL=/
initrd /initrd-x.x.x.img
(Note: )
Look at the previous parameters in the grub.conf file and note what "root=" and use what is existing.

Exit and Save grub.conf
type "/sbin/grub-install"

AND REBOOT!!!

<-> And Finally Edit Your /etc/lilo.conf file <->
image = /boot/vmlinuz-x.x.x
label = New Kernel :D
root = /dev/hdx
read-only

(Note: )
look at the previous parameters in the lilo.conf file and note what "root =" and use what exists.

Exit and Save lilo.conf
type "/sbin/lilo"

AND REBOOT!!!

/EDIT
By request: the instructions on how to apply patches to your kernel.
END EDIT/

[http://www.linuxhq.com/patch-howto.html read this] or look below ...

This step comes after untarring your kernel source.
When you download the patch, place it in the folder where you untarred your new kernel.
Then type: 
patch -E -p1 < sound_patch 
Purely an example and you would type whatever the file name is in replace of sound_patch.

Regarding having alternative boot options, this is no problem. The stuff above that I tell you to add to your lilo or grub file above could just be appended to the file, and you could just add ".old" to the title of your original kernel name for you will know the difference. Whether it's grub or lilo, add "read-only" to the end of the original entries in the lilo.conf, or grub.conf, file.

=== Special notes for Debian Users ===
Debian has some utilities to make your life a little easier. The kernel-package set of utilities allows to to create your own kernel package. For most users, this just means that your kernel shows up like all other debian packages. However, if you have multiple machines running the same kernel, it allows an easy way to install it on all of them. So let's get started.

First, make sure you have the kernel-package tools. You can install them with the command apt-get install kernel-package.

The initial steps are the same, make clean, make menuconfig (or xconfig etc...). Once your kernel is configured, type make-kpkg kernel_image and it will make your kernel.

Assuming the compile was successful, it will create a .deb in /usr/src which you can then install by typing dpkg -i kernel-package-filename, follow the instructions and reboot.

You can also create a custom kernel name (to avoid overwriting other kernels you have made) by typing something like: make-kpkg kernel_image --revision=custom.1.

This is just a quick review of the commands you need, for more information check out this [http://newbiedoc.sourceforge.net/tutorials/kernel-pkg/index-kernel-pkg.html guide] to compiling using the kernel package program.

Talk:Unix

2004-03-07T22:38:10Z

Muir:

Actually, capitalizing UNIX is more a matter of preference, it's not the prefered way Unix is spelled, especially considering that it's not an acronym. If anything, the correct way to spell it would be simply Unix.

----
UNIX is in all caps on www.unix-systems.org/. Apparently, UNIX, the trademarked name for an operating system is in all caps. We'd better get this distinction straight; it probably even merits two separate articles. Correction: both capitalizations refer to the same thing; the all caps thing had something to do with overuse of [[troff]]. See the [[Jargon File]] on the subject...

[[User:EvilSporkMan|EvilSporkMan]] 16:17, Mar 7, 2004 (EST)

----

I have a strong preference for "unix" because I don't think it is a proper noun. The current holder of the Unix trademark (X/Open?) would prefer that we all stick to Unix, but I see no reason we shouldn't express our view that unix is a descriptive noun describing a class of operating systems. Writing it "unix" is a good way to make the point.

[[User:Muir|Muir]] 17:38, Mar 7, 2004 (EST)

SPF

2004-03-07T04:53:31Z

Muir:

==External Links==
* [http://en.wikipedia.org/wiki/Sender_Permitted_From Wikipedia:Sender_Permitted_From]
* [http://spf.pobox.com/ SPF home page]

Sender verification

2004-03-07T04:50:54Z

Muir:

The main mail protocol, [[SMTP]] has a hole in it: there is no verification of the sender. This allows spammers and others to pretend to be anyone they want.

There are several new protocols for fixing this:
* [[SPF]]
* [[Caller ID for E-Mail]]

Security

2004-03-07T04:46:19Z

Muir: add Sender Verification

Security

* [[Linux Security Basics]]
** [[Basic Linux file system attributes]]
** [[Linux security vulnerabilities]]
** [[Basic principles of information privacy and security]]
* [[Remote Shell Access]]
** [[Telnet and SSH|Why ''not'' to use Telnet]]
** [[Using SSH|Basic SSH usage]]
*** [[Configuring the OpenSSH SSH daemon]]
*** [[Using the OpenSSH SSH client]]
*** [[Using SCP and SFTP to transfer files]]
** [[Advanced SSH usage]]
*** [[OpenSSH chrooting|Creating chroot environments with OpenSSH]]
*** [[X11 forwarding with OpenSSH]]
*** [[Tunneling with OpenSSH]]
** [[rsyncBackups|Secure backups with rsync]]
* [[Firewall|Firewalls]]
** [[Iptables|iptables/netfilter]]
** [[Manual configuration of an iptables firewall]]
*** [[A basic firewall configuration suitable for a workstation]]
*** [[A basic firewall configuration suitable for a gateway/nat]]
** [[Scripted firewall configuration]]
*** [[Shorewall configuration tool for netfilter]]
** [[Graphical and automated firewall configuration]]
*** [[Using GNOME lokkit for firewall configuration]]
* [[Securing Email]]
** [[Sender Verification]]
** [[Spam Filtering]]
** [[Spam Filtering on the desktop]]
** [[Virus/worm Filtering]]
** [[Using GPG to cryptographically sign email]]
* [[Securing servers and services]]
** [[Securing Apache]]
** [[Securing SAMBA]]
** [[Services under inetd and xinetd]]
* [[Hardening against users with physical access]]
** [[Securing LILO]]
** [[Securing GRUB]]
** [[Securing the BIOS]]
** [[Securing init and login]]
** [[Configuring a basic kiosk mode]]
* [[Securing against local users]]
* [[System usage and security logging]]
* [[Identifying and recovering from compromises]]

Internet Relay Chat

2004-03-07T03:30:15Z

Muir:

'''IRC''': ''Internet Relay Chat'' - one of the older widespread messaging protocols; similar to the popular IM networks, but ordinarily used for chat rooms rather than [[instant messaging]]. Servers are distributed and can be run by anyone, so IRC is a very [[free]] place. It houses help channels for almost all major [[Linux]] distributions, as well as rooms devoted to just about every topic imaginable. Channels have "operators" who can kick or mute anyone in the room. It also features the ability to send files. Like any large community, it does have its seedier regions, so be wary when venturing forth. (i.e. SexNet is probably not a good starting place for the easily offended.)

IRC is a battleground as people try to take over channels from each other. The battles are fought by disabling the systems of the people who currently control a channel.

 
''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]] !''
 

See also [[Getting help from IRC]]

Talk:Perl

2004-03-07T00:36:14Z

Muir:

so. we can't just have a redirect from PERL to Perl, or from Perl to PERL, lest a flame war start. how is this to be resolved. there is already an extensive entry for PERL.

the perlfaq says that it should not be PERL but that does not seem to be particularly set in stone, esp. since perl is ostensibly an acronym and as such potentially warrants all caps.

---

There is no current '''PERL''' page, actually. It might best to take the existing '''Perl''' and '''Perl tips''' page and stick the whole shebang under '''PERL'''. Then add redirects thusly:

Perl -> PERL
 
perl_tips -> PERL

 
Sound ok?
[[User:Mhouliston|Mhouliston]] 18:54, Mar 6, 2004 (EST)
----

What about a flip flop?

PERL -> Perl
 
perl_tips -> Perl

because of this in perlfaq1:
<code>
What's the difference between "perl" and "Perl"?

One bit. Oh, you weren't talking ASCII? :-) Larry now uses "Perl" to
signify the language proper and "perl" the implementation of it, i.e.
the current interpreter. Hence Tom's quip that "Nothing but perl can
parse Perl." You may or may not choose to follow this usage. For
example, parallelism means "awk and perl" and "Python and Perl" look
OK, while "awk and Perl" and "Python and perl" do not. But never write
"PERL", because perl is not an acronym, apocryphal folklore and post-
facto expansions notwithstanding.
</code>

----

A similar (though less difficult) thing happened with [[Spam]] and [[SPAM]]. Perhaps page titles should be case-insensitive in general.

[[User:Muir|Muir]] 19:36, Mar 6, 2004 (EST)

Hardware

2004-03-06T23:28:44Z

Muir:

Don't forget to check out the [http://www.linuxquestions.org/hcl/index.php LinuxQuestions.org HCL] and add your product reviews.

* Hardware with X Windows
** [[Configuring mice (Serial, PS/2, USB)]]
** [[Configuring keyboards]]
** [[Using multiple monitors with Xinerama]]
* Sound
** [[OSS]]
** [[ALSA]]
* Printers
** [[Adding local printers]]
** [[Adding network printers]]
* Disks
** [[IDE vs SCSI vs SATA]]
** [[IDE Tree Mapping]]
** [[IDE CD Writer]]
** [[LVM]]
** [[RAID]]
* Other Peripherals
** [[Hotplugging devices]]
** [[PCMCIA]]
** [[USB]]
** [[Firewire]]
** [[Scanners]]

Spam

2004-03-06T23:20:52Z

Muir:

1) Spam (upper case S): Registered trademark of Hormel Foods Corporation, applied to a meat product consisting primarily of processed pork.

2) spam or SPAM: Unsolicited email (AKA [[UBE]]), usually commercial in nature, and usually sent in vast quantities through [[open relays]] to email addresses that have been harvested from websites, and (apparently) distributed on CDs. The electronic equivalent of postal junk mail, but more annoying. Spam derives its name from an amusing sketch by 1970s British surrealist comedians ''Monty Python's Flying Circus'', in which the word "Spam" (referring to the meat product) is repeated ad infinitum and with increasing insistence.

[[Spammers]] do not appear to have been greatly dissuaded by recent laws banning unsolicited commercial email in both the US and Europe. However, there are techniques and software available for Linux that can be used to make spam less of a nuisance.

See also [[Spam Filtering]].

===External link===
* [http://en.wikipedia.org/wiki/Spam_(e-mail) Complete article on SPAM at Wikipedia]

 
''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]] !''

Spam filtering

2004-03-06T23:20:27Z

Muir:

Most email on the Internet is unsolicited commercial
email, also known as [[SPAM]]. The problem is not only annoying for users, but has been proven to cause stress. For providers the problem is expensive, since the massive amount of e-mails consume a lot of bandwidth, performance and hard-disk on the servers.

There are several ways to reduce the number of e-mails that ultimately reach your mail client. In many cases the preferred method is using the server to fight the problem in the first place. However this needs some consideration, because simply rejecting e-mails can piss-off legitimate users.

===Recommended SPAM filters===
There are several filters that analyze the e-mails the moment it has arrived on the server. Since the main resource being used on larger systems is diskspace, it can be interesting to reject SPAM (and thus save the diskspace) and use the processing power to run multiple applications. The most prominent filters are:
* [http://www.spamassassin.org SpamAssassin] is a free spam filtering system that filters about 95% of the spam out of a mail stream with only a small false-positive rate. The tool can tag e-mails to prevent e-mails from being lost. SpamAssassin does not need to be trained.

* [http://crm114.sourceforge.net/ CRM114] is an email filtering system much like SpamAssassin. The author claims it has 99.984% accuracy. Can be trained with personal email or existing database.

===Recommended Blacklists (RBL's)===
SPAM e-mails are typically sent, while trying to hide the real sender. People abuse other systems to get their message into the world. Several parties have started efforts to blacklists IP-addresses that are mainly used to sent SPAM. By [[addingRBLs|adding]] some of these blacklists to your MTA, or Mail Transfer Agent, like Postfix, QMail or Sendmail you reduce the number of e-mails (mainly SPAM) that arrive at your webserver. The major blacklists can be found here:
* ipwhois.rfc-ignorant.org checks if the IP-address is properly in DNS
* bl.spamcop.net
* relays.ordb.org
* opm.blitzed.org
* list.dsbl.org
* sbl.spamhaus.org
* cbl.abuseat.org
* dul.dnsbl.sorbs.net
* blackhole.securitysage.com
* virus.rbl.spamtrap.nl IP addresses known to sent viruses along.
* cbl.abuseat.org

===Spam Filtering Techniques===
*[[Bayesian Filtering]]
** [[SpamAssassin]], [[SpamBayes]], [[PopFile]], [[bmf]], [[ifile]], [[dspam]], others?
*[[Whitelist Filtering]]
** [[Procmail]], [[TMDA]], others?
*[[Blacklisting]]
**[[RBL]], others?

SPAM

2004-03-06T23:13:39Z

Muir:

Spam

2004-03-06T23:13:23Z

Muir:

1) Spam (upper case S): Registered trademark of Hormel Foods Corporation, applied to a meat product consisting primarily of processed pork.

2) spam or SPAM: Unsolicited email (AKA [[UBE]]), usually commercial in nature, and usually sent in vast quantities through [[open relays]] to email addresses that have been harvested from websites, and (apparently) distributed on CDs. The electronic equivalent of postal junk mail, but more annoying. Spam derives its name from an amusing sketch by 1970s British surrealist comedians ''Monty Python's Flying Circus'', in which the word "Spam" (referring to the meat product) is repeated ad infinitum and with increasing insistence.

[[Spammers]] do not appear to have been greatly dissuaded by recent laws banning unsolicited commercial email in both the US and Europe. However, there are techniques and software available for Linux that can be used to make spam less of a nuisance.

*[[Bayesian Filtering]]
** [[SpamAssassin]], [[SpamBayes]], [[PopFile]], [[bmf]], [[ifile]], [[dspam]], others?
*[[Whitelist Filtering]]
** [[Procmail]], [[TMDA]], others?
*[[Blacklisting]]
**[[RBL]], others?

See also [[Spam Filtering]].

===External link===
* [http://en.wikipedia.org/wiki/Spam_(e-mail) Complete article on SPAM at Wikipedia]

 
''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]] !''

Spam filtering

2004-03-06T23:05:40Z

Muir:

Vi

2004-03-06T23:02:12Z

Muir:

== vi ==
vi is a text editor that is unique in that it has two primary modes, a command mode and an edit mode. When your first start the program, it starts in command mode where anything you type is treated as a command. Some version of vi can be found on most if not all *NIX systems including [[Linux]]. It is therefore useful to know some basic commands.

=== Basic Commands ===
Typing the letter "i" (for insert) will allow you to start typing from the location of your cursor. You can use the escape key to get back into command mode.

Some of the more common commands and their meanings:
<pre>
i - insert
x - delete
:w - save (write)
:wq - save (write) and quit
</pre>

=== Other useful commands ===
I will not try to list all of vi's commands here, I will try and list some of the more useful ones that I find myself frequently using. It should also serve as an overview of what you can do with vi. (all commands are issued from command mode)
<pre>
ZZ - another way to save and quit
:q! - quits without saving the file
:w - saves the file (note that appending q will save and then quit)
:w path/filename - save the file you are working on in the directory path called filename
/some text - searches from your current position forward for "some text"
pressing / again will search for the last thing you searched for.
To search backwards, use ? instead of /
</pre>

=== Navigation ===
Vi also has some handy ways of moving around in a document. In command mode, the letters h,j,k,l will move the cursor left, down, up, right respectively. 0 (zero) will move you to the beginning of the line and $ will move you to the end of the line.

If you have a more modern keyboard with arrow keys, you can use them to navigate as well.

=== History ===
The original vi did not have sources available and was not free, but now, has been relicensed and is available for download [http://ex-vi.berlios.de/]. Because the original vi was not free, clones were created. (see links below)

=== vim ===
Vim is probably the most popular vi clone and since most distributions come with vim. Vim is an improved version of the vi editor distributed with most UNIX systems. Unlike the original vi, it also has a graphical version called gvim.

Vim isn't a word processor. Although it can display text with various forms of highlighting and formatting, the formatting is just on screen and it still saves the file as regular text. If you wish to use it as a word processor, you will need to use it in combination with a typsetting language such as [[TeX]] or [[laTeX]].

=== nvi ===
Short for ''n''ew ''vi'', it was developed at University of California at Berkley. In the early 1990s, [[BSD]] developers wanted a vi whose source code could be freely distributed. They started with elvis 1.8 though little elvis code still exists.

Nvi is very close to the original vi but with limits removed and some features added: split screen editing; file completion; infinate undo/redo and overstrike mode. Nvi does not include many
of the little used features that exist in VIM. It is ''lighter'' than VIM.

=== elvis ===
elvis was written and is currently maintained by Steve Kirkendall. An early version (1.8) was the basis for nvi. It is available on many operating systems.

=== External links ===
* [http://www.vim.org/ Official VIM website] - VI iMproved
* [http://www.bostic.com/vi/ nvi]
* [http://elvis.the-little-red-haired-girl.org/ elvis] - another version of vi
* [http://www.mrs.umn.edu/cs/unix/vi.html List of the commands in vi]

Vi

2004-03-06T23:00:48Z

Muir:

== vi ==
vi is a text editor that is unique in that it has two primary modes, a command mode and an edit mode. When your first start the program, it starts in command mode where anything you type is treated as a command. Some version of vi can be found on most if not all *NIX systems including [[Linux]]. It is therefore useful to know some basic commands.

=== Basic Commands ===
Typing the letter "i" (for insert) will allow you to start typing from the location of your cursor. You can use the escape key to get back into command mode.

Some of the more common commands and their meanings:
<pre>
i - insert
x - delete
:w - save (write)
:wq - save (write) and quit
</pre>

=== Other useful commands ===
I will not try to list all of vi's commands here, I will try and list some of the more useful ones that I find myself frequently using. It should also serve as an overview of what you can do with vi. (all commands are issued from command mode)
<pre>
ZZ - another way to save and quit
:q! - quits without saving the file
:w - saves the file (note that appending q will save and then quit)
:w path/filename - save the file you are working on in the directory path called filename
/some text - searches from your current position forward for "some text"
pressing / again will search for the last thing you searched for.
To search backwards, use ? instead of /
</pre>

=== Navigation ===
Vi also has some handy ways of moving around in a document. In command mode, the letters h,j,k,l will move the cursor left, down, up, right respectively. 0 (zero) will move you to the beginning of the line and $ will move you to the end of the line.

If you have a more modern keyboard with arrow keys, you can use them to navigate as well.

=== History ===
The original vi did not have sources available and was not free, but now, has been relicensed and is available for download [http://ex-vi.berlios.de/]. Because the original vi was not free, clones were created. (see links below)

=== vim ===
Vim is probably the most popular vi clone and since most distributions come with vim. Vim is an improved version of the vi editor distributed with most UNIX systems. Unlike the original vi, it also has a graphical version called gvim.

Vim isn't a word processor. Although it can display text with various forms of highlighting and formatting, the formatting is just on screen and it still saves the file as regular text. If you wish to use it as a word processor, you will need to use it in combination with a typsetting language such as [[TeX]] or [[laTeX]].

=== nvi ===
Short for ''n''ew ''vi'', it was developed at University of California at Berkley. In the early 1990s, BSD developers wanted a vi whose source code could be freely distributed. They started with elvis 1.8 though little elvis code still exists.

Nvi is very close to the original vi but with limits removed and some features added: split screen editing; file completion; infinate undo/redo and overstrike mode. Nvi does not include many
of the little used features that exist in VIM. It is ''lighter'' than VIM.

=== elvis ===
elvis was written and is currently maintained by Steve Kirkendall. An early version (1.8) was the basis for nvi. It is available on many operating systems.

=== External links ===
* [http://www.vim.org/ Official VIM website] - VI iMproved
* [http://www.bostic.com/vi/ nvi]
* [http://elvis.the-little-red-haired-girl.org/ elvis] - another version of vi
* [http://www.mrs.umn.edu/cs/unix/vi.html List of the commands in vi]

Vi

2004-03-06T19:47:57Z

Muir:

== vi ==
vi is a text editor that is unique in that it has two primary modes, a command mode and an edit mode. When your first start the program, it starts in command mode where anything you type is treated as a command. Some version of vi can be found on most if not all *NIX systems including [[Linux]]. It is therefore useful to know some basic commands.

=== Basic Commands ===
Typing the letter "i" (for insert) will allow you to start typing from the location of your cursor. You can use the escape key to get back into command mode.

Some of the more common commands and their meanings:
<pre>
i - insert
x - delete
:w - save (write)
:wq - save (write) and quit
</pre>

=== Other useful commands ===
I will not try to list all of vi's commands here, I will try and list some of the more useful ones that I find myself frequently using. It should also serve as an overview of what you can do with vi. (all commands are issued from command mode)
<pre>
ZZ - another way to save and quit
:q! - quits without saving the file
:w - saves the file (note that appending q will save and then quit)
:w path/filename - save the file you are working on in the directory path called filename
/some text - searches from your current position forward for "some text"
pressing / again will search for the last thing you searched for.
To search backwards, use ? instead of /
</pre>

=== Navigation ===
Vi also has some handy ways of moving around in a document. In command mode, the letters h,j,k,l will move the cursor left, down, up, right respectively. 0 (zero) will move you to the beginning of the line and $ will move you to the end of the line.

If you have a more modern keyboard with arrow keys, you can use them to navigate as well.

=== History ===
The original vi did not have sources available and was not free, but now, has been relicensed and is available for download [http://ex-vi.berlios.de/]. Because the original vi was not free, clones were created. (see links below)

=== vim ===
Vim is probably the most popular vi clone and since most distributions come with vim. Vim is an improved version of the vi editor distributed with most UNIX systems. Unlike the original vi, it also has a graphical version called gvim.

Vim isn't a word processor. Although it can display text with various forms of highlighting and formatting, the formatting is just on screen and it still saves the file as regular text. If you wish to use it as a word processor, you will need to use it in combination with a typsetting language such as [[TeX]] or [[laTeX]].

=== nvi ===
Short for ''n''ew ''vi'', it was developed at University of California at Berkley. In the early 1990s, BSD developers wanted a vi whose source code could be freely distributed. They started with elvis 1.8 though little elvis code still exists.

Nvi is very close to the original vi but with limits removed and some features added: split screen editing; file completion and overstrike mode. Nvi does not include many
of the little used features that exist in VIM. It is ''lighter'' than VIM.

=== elvis ===
elvis was written and is currently maintained by Steve Kirkendall. An early version (1.8) was the basis for nvi. It is available on many operating systems.

=== External links ===
* [http://www.vim.org/ Official VIM website] - VI iMproved
* [http://www.bostic.com/vi/ nvi]
* [http://elvis.the-little-red-haired-girl.org/ elvis] - another version of vi
* [http://www.mrs.umn.edu/cs/unix/vi.html List of the commands in vi]

User:Muir

2004-03-06T07:45:58Z

Muir:

David Sharnoff

Owner of the ISP [http://www.idiom.com Idiom].

CPAN [http://search.cpan.org/~muir contributor].

Spam filtering

2004-03-06T07:42:25Z

Muir:

Most email on the Internet is unsolicited commercial
email (SPAM).

[http://www.spamassassin.org SpamAssassin] is a free
spam filtering system that filters about 95% of the spam
out of a mail stream with only a small false-positive
rate.

Security

2004-03-06T07:31:24Z

Muir:

Security

* [[Linux Security Basics]]
** [[Basic Linux file system attributes]]
* [[Remote Shell Access]]
** [[Telnet and SSH|Why ''not'' to use Telnet]]
** [[Using SSH|Basic SSH usage]]
*** [[Configuring the OpenSSH SSH daemon]]
*** [[Using the OpenSSH SSH client]]
*** [[Using SCP and SFTP to transfer files]]
** [[Advanced SSH usage]]
*** [[OpenSSH chrooting|Creating chroot environments with OpenSSH]]
*** [[X11 forwarding with OpenSSH]]
*** [[Tunneling with OpenSSH]]
** [[rsyncBackups|Secure backups with rsync]]
* [[Firewall]]
** [[Manually configuring a basic netfilter/iptables firewall]]
* [[Securing Email]]
** [[Spam Filtering]]
** [[Virus/worm Filtering]]
* [[Securing Apache]]
* [[Securing SAMBA]]