Apache Glossary
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CLF Common Log Format
A format defines the informations related to the received requests that Apache is to record into a log file. A log file is defined by the Apache administrator using the CustomLog or a TransferLog directive. If no format is defined in either case, the Common Log Format is assigned to the file. The configuration file, named httpd.conf contains the directives that define the configuration of an Apache system. It is processed when Apache is started. Therefore, for any change in the configuration file to take effect, the Apache system has to be restarted.configuration panel Windows:
To display the configuration panel:| - | click on the START button in the left button corner of the screen |
| - | click on the Configuration panel icon |
- "B" and "C" contained in "A" - "D" and "E" contained in "C" - "F" contained in "E" The directories "B", "C", "D", "E" and "F" are all descendants of "A". "A" is an ancestor of them all. "A" is the parent of "B" and "C". The latter are the children of "A". | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
- "B" and "C" contained in "A" - "D" and "E" contained in "C" - "F" contained in "E"
In this structure, some examples of directory paths are: | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The domain name identifies an individual network in the Internet. In the simplest case, the individual network can be one isolated computer. But a domain in the Internet must be conceived of as a network.
This is a name composed of two words separated by a dot.
The word on the right identifies the domain manager. The word on the left identifies is the domain name proper, which identifies a network.
A domain can be divided into subdomains. The subdomains may identify the computers that compose the domain network. The subdomains are identified by a name composed of the domain name, preceded by the subdomain name and a separating dot.
For example, a domain name can be hatayservices.com. In this:
| com | is the name of a domain manager |
| hatayservices | identifies a domain within the com domain manager - this domain is a network |
In large domains, a subdomain of the domain can be a network, which can be further divided. A sub-subdomain has a name composed of the subdomain name, preceded by a name and a separating dot. For example: appl.server.hatayservices.com
Subdividing can go on like this, with the subdivision names extending to the left.
| User program | ||||||||||
| DRIVER | DATABASE | |||||||||
environment variable panel Windows:
In NT or XP Windows systems, a number of system parameters can be defined through the system properties panel.| - | show the My Computer icon, by clicking on the Start icon, or displaying the Windows Explorer tree |
| - | click on the My Comùputericon with the mouse right button (left button on a lefthander mouse) - a selection menu will show |
| - | click on "Properties" - a tagged configuration panel will show |
| - | you can click on the "Advanced" tag -- a panel with a number of buttons will show |
| - | clicking on the "Environment Variables" would display the boxes for creating or modifying system or user environment variables. |
| - | the CLASSPATH variable used by Java is a user variable. If it did not exist, you can click on the "New" button to create and assign it a value. If it did exist, you click on the "Modify" button to modify or add a new path. To point the CLASSPATH to the C:\myfiles\appl\java\classes directory, you set C:\myfiles\appl\java\classes as the value of the CLASSPATH variable. To point the variable to one more directory, say C:\java\test, you add this path to the CLASPATH value, with a semi-colon (no space) to separate the 2 paths: C:\myfiles\appl\java\classes;C:\test\java For more informations on how Java works, see the JavaClasspath.html document. |
A file path is denoted by the corresponding sequence of directory names, in the order of the sequence, followed by the file name. These names separated by a slash, or a backslash, depending of the context. Example, referring to the figure on the left: A/C/D/somefile.txt or A\C\D\somefile.txt | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
In the example shown on the left, the .htaccess file contains the access informations related to the D directory. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| - | input fields which can be text-entry fields, check buttons, etc. |
| - | submit buttons |
| - | the URL of the destination where the informations entered into the form are to be sent |
| - | free presentation text |
HTTP HyperText Transfer Protocol
HTTP is a protocol used for message transfer in the Internet. It is the protocol used by Apache.| Accept | indicates the type of data a user can accept in the response to its request |
| Content-Type | describes the data type of a message contents |
| Referer | identifies the resource from which the request URI (as sent to the server) was obtained |
| 200 | OK |
| 400 | bad request |
| 404 | the requested resource was not found. As stated in the RFC1626 official HTTP 1.1 document: "This status code is commonly used when the server does not wish to reveal exactly why the request has been refused" |
| 500 | for some reason, the server could not process the request |
The new format with 6 bytes, called IPv6 is being implemented, to be widely used in the near future.
ISAPI: Internet Server Application Programming Interface
Short for Internet Server API, an API for Microsoft's IIS (Internet Information Server) Web server. ISAPI enables programmers to develop Web-based applications that run much faster than conventional CGI programs because they're more tightly integrated with the Web server. In addition to IIS, several Web servers from companies other than Microsoft support ISAPI. These include Apache. MD5 is a program that generates pseudo-random numbers based on a key. The result is a 16 bytes number.http://host-id:port/path-info?parameters |
If path-info does not start with an alias nor contains a tilde (~) sign, this path is evaluated relative to the Apache document root
If path-info starts with an alias, the path starts at the directory identified by the alias. It path-info contains a tilde (~) sign, the path can relate to a user file structure.
See also directory path and file path above.
In Apache authorization procedures, directories are grouped into realms. Users are authorized to access a realm rather than an individual directory.A directory is assigned to a realm when defining the users authorized to access it. A realm is just a name. All directory assigned the same realm name, pertain to the same realm.
After a user has produced the necessary password to access a directory pertaing to a realm, he has not to enter his password again to access another directory of the same realm.
A regular expression is a pattern to be matched by character strings.SSI - Server Side Include
An SSI element is an element inserted in an HTML page, which can be decoded by the SSI function of Apache, before the page is sent to a requesting client. Based on the element contents, an information is generated and placed in the HTML page, at the location where the element is inserted. An example os such information is the current date and time. see HTTP status A directory and file structure where a directory can contain files and other directories can be represented by a mathematical structure called a tree.
A node connected by a line to a node above it, is one of the latter's children. A node is the parent of its children. In a tree structure:
In the example on the left, the nodes labelled "D", "E" and "F" are children of the node "C". This node is the parent of "D", "E" and "F". The node labelled "A" is the root. This structure can be used to represent a structure of directories and files. In this presentation, a directory or a file is represented by a node of the tree. A file or directory contained in a directory is represented by a child of the node representation of the latter. A file is a node with no child. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| space character | ASCII code: #x0020 |
| carriage return character | ASCII code: #x000D |
| line feed character | ASCI code: #x000A |
| tab character | ASCII code: #x0009 |
| form feed character | ASCII code: #000C2 |
| zero-width-space character | ASCII code: #x200B |
These characters usually serve to enhance the legibility of a document to a human reader, but have no semantic signification. Document processors usually treat a sequence of them as a single space character. Also, when transcribing a document, they often replace them with a single space.