[ Pobierz całość w formacie PDF ]
.Moreover, the link to bert only uses a slow 2400bpsmodem.moria's would publish the following maps entry:moria.orcnet.orgbert.sesame.com DAILY 2 ,swim.twobirds.com WEEKLY+LOWmoria.orcnet.org = moriaThe last line would make it known under its UUCP name, too.Note that it must beDAILY 2, because calling twice a day actually halves the cost for this link.Using the information from such map les, pathalias is able to calculate optimal routesto any destination site listed in the paths le, and produce a pathalias database from thiswhich can then be used for routing to these sites.pathalias provides a couple of other features like site-hiding i.e.making sites accessibleonly through a gateway etc.See the manual page for pathalias for details, as well as acomplete list of link costs.Comments in the map le generally contain additional information on the sites describedin it.There is a rigid format in which to specify this, so that it can be retrieved from themaps.For instance, a program called uuwho uses a database created from the map les todisplay this information in a nicely formatted way.When you register your site with an organization that distributes map les to its mem-bers, you generally have to ll out such a map entry. 13.6.Con guring elm 224Below is a sample map entry in fact, it's the one for my site :N monad, monad.swb.de, monad.swb.sub.orgS AT 486DX50; Linux 0.99O privateC Olaf KirchE okir@monad.swb.deP Kattreinstr.38, D-64295 Darmstadt, FRGL 49 52 03 N 08 38 40 EU brewhqW okir@monad.swb.de Olaf Kirch ; Sun Jul 25 16: 59: 32 MET DST 1993monad brewhq DAILY 2Domainsmonad = monad.swb.demonad = monad.swb.sub.orgThe white space after the rst two characters is a TAB.The meaning of most of theelds is pretty obvious; you will receive a detailed description from whichever domain youregister with.The L eld is the most fun to nd out: it gives your geographical positionin latitude longitude and is used to draw the postscript maps that show all sites for eachcountry, as well as world-wide.513.6 Con guring elmelm stands for electronic mail" and is one of the more reasonably named un?x tools.Itprovides a full-screen interface with a good help feature.We won't discuss here how to useelm, but only dwell on its con guration options.Theoretically, you can run elm uncon gured, and everything works well |if you arelucky.But there are a few options that must be set, although only required on occasions.When it starts, elm reads a set of con guration variables from the elm.rc le inusr lib elm.Then, it will attempt to read the le.elm elmrc in your home directory.You don't usually write this le yourself.It is created when you choose save options" fromelm 's options menu.The set of options for the private elmrc le is also available in the global elm.rc le.Most settings in your private elmrc le override those of the global le.5They are posted regularly in news.lists.ps-maps.Beware.They're HUGE. 13.6.Con guring elm 22513.6.1 Global elm OptionsIn the global elm.rc le, you must set the options that pertain to your host's name.Forexample, at the Virtual Brewery, the le for vlager would contain the following:The local hostnamehostname = vlagerDomain namehostdomain =.vbrew.comFully qualified domain namehostfullname = vlager.vbrew.comThese options set elm 's idea of the local hostname.Although this information is rarelyused, you should set these options nevertheless.Note that these options only take e ectwhen giving them in the global con guration le; when found in your private elmrc, theywill be ignored.13.6.2 National Character SetsRecently, there have been proposals to amend the RFC 822 standard to support varioustypes of messages, such as plain text, binary data, Postscript les, etc.The set of standardsand RFCs covering these aspects are commonly referred to as MIME, or MultipurposeInternet Mail Extensions.Among other things, this also lets the recipient know if a characterset other than standard ASCII has been used when writing the message, for example usingFrench accents, or German umlauts.This is supported by elm to some extent.The character set used by Linux internally to represent characters is usually referredto as ISO-8859-1, which is the name of the standard it conforms to.It is also known asLatin-1.Any message using characters from this character set should have the followingline in its header:Content-Type: text plain; charset=iso-8859-1The receiving system should recognize this eld and take appropriate measures whendisplaying the message.The default for text plain messages is a charset value of us-ascii.To be able to display messages with character sets other than ASCII, elm must knowhow to print these characters.By default, when elm receives a message with a charset eld 13.6.Con guring elm 226other than us-ascii or a content type other than text plain, for that matter , it tries todisplay the message using a command called metamail.Messages that require metamail tobe displayed are shown with an `M' in the very rst column in the overview screen.Since Linux' native character set is ISO-8859-1, calling metamail is not necessary todisplay messages using this character set.If elm is told that the display understands ISO-8859-1, it will not use metamail but will display the message directly instead.This can bedone by setting the following option in the global elm.rc:displaycharset = iso-8859-1Note that you should set this options even when you are never going to send or receiveany messages that actually contain characters other than ASCII.This is because peoplewho do send such messages usually con gure their mailer to put the proper Content-Type:eld into the mail header by default, whether or not they are sending ASCII-only messages.However, setting this option in elm.rc is not enough.The problem is that when dis-playing the message with its builtin pager, elm calls a library function for each characterto determine whether it is printable or not.By default, this function will only recognizeASCII characters as printable, and display all other characters as ^?".You may overcomethis by setting the environment variable LC CTYPE to ISO-8859-1 , which tells the libraryto accept Latin-1 characters as printable.Support for this and other features is availablesince libc-4.5.8.When sending messages that contain special characters from ISO-8859-1, you shouldmake sure to set two more variables in the elm.rc le:charset = iso-8859-1textencoding = 8bitThis makes elm report the character set as ISO-8859-1 in the mail header, and send itas an 8 bit value the default is to strip all characters to 7 bit.Of course, any of these options can also be set in the private elmrc le instead of theglobal one. Chapter 14Getting smail Up and RunningThis chapter will give you a quick introduction to setting up smail, and an overview ofthe functionality it provides.Although smail is largely compatible with sendmail in itsbehaviour, their con guration les are completely di erent.The main con guration le is the usr lib smail con g.You always have to edit thisle to re ect values speci c to your site.If you are only a UUCP leaf site, you will haverelatively little else to do, ever.Other les that con gure routing and transport optionsmay also be used; they will be dealt with brie y, too.By default, smail processes and delivers all incoming mail immediately.If you haverelatively high tra c, you may instead have smail collect all messages in the so-calledqueue, and process it at regular intervals only.When handling mail within a TCP IP network, smail is frequently run in daemon mode:at system boot time, it is invoked from rc [ Pobierz całość w formacie PDF ]