Smart Usage

Other WWW commands

In the preceding section, you have learnt the basic commands of the World-Wide Web, to access information by following links or by searching for keywords. But other commands are available to facilitate your navigation through the realm of information.

At the prompt level, you may type any of the following commands. They can all be abbreviated, and case is not significant. We will also recall the commands you already know.

Basic commands
Number
A number by itself selects a reference from within the displayed text and follows the corresponding link, i.e. displays the document referred to.
K (Keyword)
The letter K introduces a list of keywords that you want to search for. This command is only available on indexed documents. This is reminded in the command prompt. Note that you can also supply keywords directly (without a leading K), provided that they don't match a command. For instance, you may type either `K BLOGGS' or `BLOGGS' to look for your friend Joe Bloggs, but if you want to know more about lists, you must type `K LIST'.
H (Help)
Display a summary of these commands, and also the hypertext address of the document you are reading, so you can quote a reference to it.
Q (Quit) or E (Exit)
Leave WWW for now.
Retrieving previously seen documents
R (Recall)
The WWW browser remembers all the documents you have looked up in a session. The Recall command displays a numbered list of the documents you have visited. To select one, type the Recall command followed by the number associated with the document you want, for instance `R 2'. Note that this new display of a previously visited node will be remembered at the end of the recall list.
B (Back)
Go back to the document you were reading before. This will erase the current document from the recall list. You can back up indefinitely.
HO (Home)
Go back to the first document you were reading (in general the Home Page). This will not erase the recall list. It is faster than backing up several times.
Viewing the current document
Top
Return to the top of the currently displayed document. (Sorry, you can't go back one page at a time. This feature will be added soon.)
List
Display a numbered list of the references encountered so far in the current document, giving the titles (or addresses) of the linked documents. To jump there, type the corresponding number by itself.

Command line syntax

WWW can be invoked from the shell. The syntax is :

www [options] [docaddress [keywords]]

With no arguments, the www shell command starts browsing from the system default page, /usr/local/lib/WWW/default.html (for systems other than Unix, see the Installation section).

Options should be specified before other arguments. Currently options available are :

-n
Non-interactive mode. Outputs the formatted document to the standard output, then exits. Pages are delimited with form feed (FF) characters. the page length depends on the -p option. This is useful to print a document when you know its address.
-pn
where n is a number, specifies the page length. Without a number, makes the page length infinite. Default is 24.
-v
Verbose mode: Gives a running commentary on the program's attempts to read data in various ways. If present, the next argument is the hypertext address of the document at which you want to start browsing. You may want to define an alias for www followed by name of your favourite index.
-na
Hides anchor positions in the text. Useful, when printing out the document.
-a format
Specifies the printf -style format string to be used when printing references. Must contain the two characters "%d" where the numbers should occur. Be sure to escape or quote any special characters you use. For example under unix, with ^[ standing for ESCape:
www -a \<%d\> www -a " (Type %d)" www -a "^[[1m[%d]^[[m" Any further command line arguments are taken as keywords. The first argument must refer to an index in this case. The index is searched for entries matching the keywords, and a list of matching entries is displayed.

Shortcuts

To save having always to go through the www default page, you can use a shortcut to get to an index. On cernvax for example, the following shell commands are predefined:
yellow
The CERN yellow pages telephone directory.
xfind
The CERN computer center documentation keyword index
vmnews
The CERN computer centre news service: all news articles, in reverse chronological order.
You can search an index which has a shortcut command by giving the keywords as parameters, eg yellow taxes To make your own shortcuts, you can define your own commands. On unix (with csh), use an alias. On Unix, alias z www address On VMS, $ Z :== 'WWW' """address""" where address is the hypertext address of the document you want to jump into. You can find the hypertext address of a node from the LIST command or the RECALL command when you are in www. (For nodes with titles, the RECALL command shows you that instead).

An alternative method uses a shell script.

Under unix, you can set up your own www command using an alias, even if you do not have system privileges.

The commands below are for the C shell (csh). If you are using the korn shell, you will replace the space between the name and value of an alias with an equals "=" sign.

To define the www command, simply make an alias to the executable file (www) in the directory in which you have put it.

alias www /path/path/path/Implementaion/machine/www If you want to make a special command to point directly to a particular hypertext document, then you must find its hypertext address. You then define an alias giving that address as a first parameter to "www". alias xfind www http://crnvmc/FIND/pub+user\? Note the backslash (\) used to prevent the question mark (here part of the address of the FIND index) from being interpreted by the shell.

Customising www

As the line mode browseris installed, it comes with a default copy of the CERN home page, frozen at the time when the distribution was made. That page has (right at the bottom) a link back to the current version.

You can customise www to start at a page of your choice. You can write your own page, or use someone else's. All you have to do is to set the environment variable WWW_HOME to the www address of your preferred home page. (When you are using www, you can see what an address looks like by typing help when you are reading a document - it tells you the address of that node).

"Environment variable" is a unix term. On VMS you should use a logical name. Under VM/CMS, set the globalv "WWW_HOME" in the table "CENV", with a command like

GLOBALV SELECT CENV SET WWW_HOME http://info.cern.ch/junk.html You can also customise www by defining your own "www" command to invoke www with certain command line optionsset, such as the page length. See making shortcut commandsfor how to make aliases.

Installing WWW

This section describes how to install the line mode browser. First of all, The browser has already been ported to VAX/Ultrix (using cc or gcc compilers), DECStation/ultrix, VAX/VMS (read the special instructions), Sun4, IBM RS6000, and Apollo_m68k, VM/CMS and MVS. If your machine is not one of these, see the section on porting. If it is, then find the relevant subdirectory of LineMode/Implementation.

Compiling

This will not be necessary if there is already a copy of the executable for your machine in the subdirectory.

Installing

You must now check that the default "Home" page works, and customise it if it is not what you want. The default home page refers explictly to certain information which we know about. You may wish to add more.

Installation under VMS

To install under VMS, get the files WWW.EXE and SETUP.COM from sources described below. To set up the commands, put the command $ @[...]SETUP into your LOGIN.COM, or the system SYLOGIN.COM. This command file assumes you have left all the distributed files in the same directory as itself.

Home page

Under VMS, the home page may be defined using the logical name WWW_HOME. You should define this to be the full address of the document which you want to be displayed when www is invoked without parameters. For example, $ DEFINE/SYSTEM WWW_HOME "file://myvax/sys$library/default.html" Note that the www address you must set it to is still in unix-like format (with slashes instead of :: : [.])Users may of course override the system logical name with their own. If no logical name is defined, the VMS browser will default to picking up the default page from our server, document http://info.cern.ch./default.html.

Availability

Versions are available for any of the following implementations of TCP/IP which you may have installed on your system: Digital's UCX, Wollongongs's WIN/TCP, or SRI's Multinet. If you are on HEPnet, the versions are currently (August 91) available in directories as follows:
Wollongong WIN_TCP
none - mail me if interested.
Multinet
vxcrna::disk$oc1:[timbl.www.multinet.works]
Digital's UCX
vxcrna::disk$oc1:[timbl.www.ucx.works]
CMU TCP
none - mail me if interested.
If you are not on HEPnet, but can pick up and unwrap the tar file from the general distribution, then you will find executables in the WWW/LineMode/Implementation/vms directory, as files www_ucx.exe or www_multinet.exe. Pick one and rename it to www.exe

Note (CERN)

If you are at CERN, you may want to pick up the default page and online documentation from cernvax. This machine is known (for reasons of history and name length limit) on decnet as PRIAM. You must therefore: $ DEFINE/SYSTEM CERNVAX PRIAM::