absolute pathname
A pathname that completely specifies the file specifications, including device and directory.
access control
The ability to control access to objects on the server by rejecting or allowing particular client requests. Client requests can be allowed or rejected according to one or more of the following criterion:
access control list (ACL)
A file that contains information indicating who can and cannot access particular objects in the data directory. Purveyor creates a separate ACL file for each restricted object, and these files determine whether users and groups can access objects on a global, virtual path, browse, or file level.
access method
A type of access control parameter that limits access to objects according to the methods clients use when making requests. Purveyor supports the following HTTP methods:
ACL
See access control list.
ACL cache
Information stored in system memory that determines access restrictions to objects in the data directory. Because the server does not have to read this information from the hard disk, ACL caching allows Purveyor to process and authenticate client requests more quickly.
address masks
IP addresses that include wildcards such as ? and *. You can use address masks to represent a series or range of IP addresses instead of entering each address individually.
authentication
Verification of the identity of a person or process.
browse access control
The type of access control that determines whether or not clients can view specific directories in the data directory as they would view items in a Gopher menu.
browser
A World Wide Web client that is capable of sending and receiving messages using the HyperText Transfer Protocol (HTTP), and is able to read and format documents written in the HyperText Markup Language (HTML).
Browsing access control (DAC)
The type of access control that determine whether or not clients can view the files in a specific directory. You can limit access to directories according to the client username, groups, methods of access, IP addresses, or any combination.
cache
The process of storing information in main memory for future use; used to minimize physical transfer of data between mass storage devices and memory.
cache lifetime
The length of time that the proxy server saves specified URLs for local access before it deletes them.
CERN
European Laboratory for Particle Physics; a laboratory in Switzerland that started the World Wide Web as a distributed hypermedia network service.
CGI
The Common Gateway Interface.
clickable images
See image maps.
client
A machine that accesses resources over the Internet. Also, an application that requests a server to execute remote procedure calls.
Common Gateway Interface (CGI)
The standard way through which HTTP servers pass information from client queries into server scripts. Using CGIs, HTTP servers can serve documents or execute programs based on data that clients provide. Typically users enter information by typing text into HTML forms.
common log format
A specific log template that a system manager enters, usually applied to the transaction log files.
DAC
See Browsing Access Control.
data directory
The root directory of the files/directories Purveyor serves to Web clients. Unless you configure virtual paths to other directories, Web clients can only view the files in this directory.
direct connection
An electrical connection to the Internet that is accomplished with an IP address and a node on the network. With a direct connection, you can take advantage of the full capabilities of the Internet and the World Wide Web.
Directory Access Control
Abbreviated VAC (formerly called Virtual Access Control). A type of access control that determines whether particular clients or groups of clients can access objects that are in a directory or one of its subdirectories. You can limit access to directories according to client user names, groups, methods of access, IP addresses, or any combination.
directory browsing
A feature which allows clients to view files and directories on the server just as they would view a Gopher menu.
DLL
See dynamic link library.
DNS lookup
A service that resolves client’s IP addresses into domain names and then records this information in the remotehost section of Purveyor’s transaction log.
domain name
A name corresponding to a domain, organized hierarchically. A domain name is fully qualified when it includes the top level domain and an ending dot.
dynamic link library (DLL)
A program module that contains executable code and data that can be used by applications or other DLLs. The DLL is linked to the application only when the program runs, and is unlinked when it is no longer needed. This provides a more efficient use of limited memory. OpenVMS terminology would call these run-time library routines. However, Purveyor uses DLL for consistency with the Purveyor family and to properly indicate to the server that these are to be loaded into the server’s memory (.DLL files are loaded) instead of being executed as a subprocess (as .EXE files are).
environment variables
System-level variables used to communicate values between processes. For example, a remote host name, a password, or the type of data to be returned are usually passed as environment variables.
FAC
See File Access Control.
file access control (FAC)
The type of access control determines whether or not clients can view specific files in the data directory. You can limit access to files according to the client usernames, groups, methods of access, IP addresses, or any combination.
File Transfer Protocol (FTP)
A common protocol for transferring files over the Internet from one machine to another.
firewall
An invisible boundary that distinguishes networked computers within that boundary from those outside it. Those within the firewall have internal access capabilities and share resources not granted to those outside it. A firewall protects one or more computers that have Internet connections from intrusion by external computers that also have connections.
forms (HTML)
HTML documents that allow users to input information which can later be processed by server applications and passed back to the client. HTML forms often contain text fields that allow users to input information and a Submit button that sends the information.
FTP
See File Transfer Protocol.
fully qualified URL
A URL that begins with a method (usually "http") followed by a colon, two slashes and other information, such as the server address and filename. You should use fully qualified URLs to refer to files that reside on another server. An example is "http://www.process.com/default.html".
GAC
See Global Access Control.
gateway
Typically, a device attached to two networks or systems that otherwise do not communicate with each other. Communications from one network to the other are routed through the gateway. A gateway can be used to filter communications between trusted and untrusted systems.
GET
An HTTP method that retrieves whatever data is identified by the URL, so that when the URL refers to a data-producing process (or a script that can be run by such a process) GET returns the data produced, not the source text of the script or process.
global access control (GAC)
The type of access control that determines whether clients can view any files or directories in the (virtual) server.You can limit access to the entire (virtual) serveraccording to the client usernames, groups, methods of access, IP addresses, security, or any combination.
Gopher
A utility that allows you to access publicly available information from the Internet. Gopher information appears in a directory structure that uses various icons to represent text, sound, video, and image files.
Gopher icons
The icons Purveyor associates with various media when presenting Gopher menus. Purveyor comes with a set of icons that represent all of the media types present in the server’s MIME mapping table.
group database
The database where Purveyor records the names and members of groups recognized by the server. The system manager can assign access permissions for files and directories on the server based on these groups.
group name
The name assigned to a group of users on a network. Members of groups share a common group of file access privileges.
HEAD
An HTTP method that retrieves only HTTP headers from data identified by the URL.
home page
The HTML document within a data directory that is intended as the primary starting point for anyone navigating that directory. If you configure virtual paths for your server it is possible to create multiple home pages. That is, you can assign a different homepage for each directory referenced by a virtual path.
host name
The name of the central or controlling computer in a networked environment, servicing requests that other computers or terminals can access through the network.
HTML
HyperText Markup Language. The standard text formatting language of the World Wide Web. Web clients interpret HTML markup and display documents and graphics according to these interpretations. HTML also allows document authors to establish HyperText links between documents in various locations on the Internet, and to create forms interfaces and clickable images that enable users to interact with Web documents.
HTP commands
Commands included within HTML documents that allow the server to customize documents as it serves them. HTP commands and tags together are often called Server Side Includes and files that include them must have the extension .HTP. These commands allow authors to include commands and tags that automatically insert the day’s date or the contents of other files, execute other programs, or print one of the variables from a CGI program.
HTTP
HyperText Transfer Protocol. The standard method of transferring information across the World Wide Web. HTTP provides a flexible means for communicating a variety of media and file formats across a variety of platforms. This enables users, by working through stable and uncomplicated interfaces, to navigate quickly and easily across a large network of multimedia resources.
HTTPS
Secure HyperText Transfer Protocol.
HyperText
Text within a document that is linked to other text, documents, images, audio, or movies.
image maps
Embedded images in HTML documents that allow users to activate HyperText links or invoke server scripts by clicking on specific areas within the images.
information protocols
A means of communicating between servers and browsers (clients). Both the server and client must agree on the protocol.
IP address
The underlying identifiers used by the protocols that govern Internet information exchange. The Internet Network Information Center assigns these identifiers to uniquely identify different machines on the Internet. These addresses can be converted to the more familiar domain name address by using the Domain Name Service:
IP Address
DNS Name
192.42.95.1
sirius.process.com
16.1.0.2
gatekeeper.dec.com
130.127.8.1
hubcap.clemson.edu
192.112.36.5
nic.ddn.mil log file directory
The directory where Purveyor stores a daily record (log) of HTTP transactions. Purveyor stores this information in a file whose name begins with the letters HS followed by the year, month, and date that the log was created. For example, a file created on July 18, 1995 would be named HS950718.LOG.
log HTTP transactions
An internal log record of HTTP transactions that the server updates at a specific time every day. The transaction log records the following information:
log template
A string of commands that determines the information stored in the log file.
map file
A file that describes the clickable regions in an image and the links to which they point by defining the coordinates of each hyperlink area and the URL of that area. A map file consists of definitions, comments, and blank lines.
MIME
See Multipurpose Internet Mail Extensions.
MIME icons
The icons the server uses to represent different objects and media when Purveyor is acting as a proxy server. These pictures show the types of files that are available to clients operating through the proxy server.
MIME mapping
A way of finding out file media content and encoding format by looking at the file’s extension. When the server encounters files with certain extensions it assumes that these files have particular kinds of contents. Some examples of common MIME types are text/plain, image/gif, and video/mpeg which the servers associates with the extensions .txt, .gif, and .mpeg.
Multipurpose Internet Mail Extensions
Abbreviation: MIME. A way of designating both the encoding method and type of media within an electronic message. Each MIME type consists of a type/subtype pair. The type indicates the message’s media content, and the subtype designates the way the message was formatted or processed. Some examples of common MIME extensions are text/plain, application/binary, image/gif, audio/basic, and video/mpeg.
partial URL
A URL that does not contain all three parts (protocol, server ID, and file ID).
password
A confidential text string assigned to each user in Purveyor’s user database. Users must enter this password in order to verify their identity when attempting to open restricted files on the data directory.
POST
An HTTP method that creates a new object linked to the specified object. Either the client or the server sets the message ID field of the new object. The server allocates a URL and returns it to the client, with the new document comprising the data part of the request. It is subordinate to the specified object, as a file is to a directory or a news article is to a newsgroup.
An abbreviation for Point-to-Point Protocol.
protocols
A set of operating rules and procedures governing communication over a network.
proxy cache
The files Purveyor stores in memory when acting as a proxy server. When the proxy server fetches data from a remote site on behalf of a client, it can store a copy of that data on a local hard disk in a "cache". The next time a client asks for the URL, Purveyor serves the file from its internal cache. This is considerably easier and quicker for the server to do than getting the data from the original source.
proxy chaining
A process by which you can specify that all proxy requests are channeled through to another proxy server, using the Chained Proxy field. You can use this feature if you are running a proxy as a local cache on behalf of part of an organization, and that organization uses another proxy for Internet communications.
proxy server
A way of configuring the server that allows corporate clients to access the World Wide Web through Purveyor, without compromising corporate security. A proxy server is typically located at a "firewall" between a corporate IP network and the rest of the Internet.
realm
A distinct set of usernames and group names. If you have more than one organization’s information on your server, you can create and allocate user and group names for each realm independently.
relative pathname
A pathname that indicates an object’s location on the directory tree relative to the current working directory.
Remote Server Management
A tool that accesses the collection of information about the configuration of Purveyor (the configuration database) that is done through HTML forms.
request
The first part of the request–response process that HTTP transactions follow. When a client wishes to open a file that exists on the server, it sends the server a request for that file. If the client has permission to read the file, the server responds by serving the file to the client. When Purveyor acts as a proxy server, it requests files from other servers on behalf of clients on the internal network. If these servers respond by serving the file, Purveyor passes it along to the internal clients.
response
The second part of the request–response process that HTTP transactions follow. When a client wishes to open a file that exists on the server, it sends the server a request for that file. If the client has permission to read the file, the server responds by serving the file to the client. Purveyor’s access control capability allows you to configure the server so that it responds to client requests according to whether or not clients have permission to view particular files. In addition, when Purveyor acts as a proxy server, it responds to internal client requests for files according to whether or not the server has been configured to screen that particular file type, location, or name.
RSM
See Remote Server Management.
script
An executable file located on the server that performs specific tasks and, if necessary, sends back specific data when called by a client. Clients usually submit these requests by operating through HTML forms.
server
A machine that provides services to the network. Also, a workstation that provides resources to other workstations called client systems.
server-parsed HTML
See server-side includes.
server side includes
Commands contained within HTML files that cause Purveyor to serve files differently according to the command and the circumstances of the request. Files that include server-side includes must have an .HTP extension.
SLIP
Serial Line Internet Protocol.
standard input
ASCII input stream which comes from either another process or from the standard input device, usually the keyboard.
standard output
ASCII output stream which goes to another process or the default output device, usually the screen.
TCP/IP
The Transmission Control Protocol (TCP) and Internet Protocol (IP) are respectively the network protocol and communication protocol used by most computers and hosts on the Internet.
TCP/IP port
The port Purveyor uses to connect to a service. Port 80 is the default.
transaction logging
See log HTTP transactions.
type of access
An access control parameter that determines whether Purveyor allows, rejects, or redirects requests from users or groups. Purveyor allows the following types of access parameters:
Uniform Resource Locator
See URL.
URL
A standard for identifying objects on the Internet accessible through the World Wide Web.
URL masks
URL addresses that include wildcards such as ? and *. You can use URL masks to represent a series or range of IP addresses instead of entering each address individually.
URL redirection
A feature that redirects client requests for a relocated document from the old address to its new location.
user
A person logged in at a client system.
user database
The database where Purveyor records the names and passwords of users that the server recognizes. You can assign access permissions to objects on the server based on these usernames and passwords. You can also create groups that include these users as members.
username
Character strings by which users identify themselves on a network.
VAC
See Directory Access Control.
virtual path
A way of providing clients with access to directories and files not in the data directory, or substituting simplified notation for long pathnames. Virtual pathnames point to specific directories or files. For instance the virtual path ~reviews could point to the pathname DISK$DATA1:[PERSONEL.EMPLOYEES.REVIEWS]. Even if Purveyor’s data directory is DISK$DATA1:[PURVEYOR.WEB], the server sends any client requests for ~reviews to the correct directory.
