The XPointer Framework provides an authoritative and extensible interpretation of the semantics of fragment identifiers for XML media types. However, HTTP does NOT transmit the fragment identifier as part of the HTTP request. Therefore XPointer is generally applied by the client, not by the server.
For example, assuming that http://www.myorg.org/myTripleStore identifies a resource that is willing to negotiate for RDF/XML, then the following is typical of an HTTP request for an RDF/XML representation of that resource and the server’s response.
Request:

GET /myTripleStore HTTP/1.1
Host: www.myorg.org
Accept: application/rdf+xml

Response:
HTTP/1.1 200 Ok
Content-Type: application/rdf+xml

This request asks for the entire triple store, serialized as RDF/XML.
Server-side XPointer uses the HTTP “Range” header to transmit the XPointer expression to the server. For example, let’s assume that the URI of the triple store is the same, but we want to select the subresources identified by the following RDQL query:
SELECT (?x foaf:mbox ?mbox)
WHERE (?x foaf:name “John Smith”) (?x foaf:mbox ?mbox)
USING foaf FOR
)

In that case the HTTP request, including a copy of the RDQL query wrapped up as an XPointer expression, looks as follows. Note that we have added a range-unit whose value is xpointer to indicate that the value of the Range header should be interpreted by an XPointer processor. Also note the use of the XPointer xmlns() scheme to set bind the namespace URI for the rdql() XPointer scheme. This is necessary since this scheme has not been standardized by the W3C.
GET /myTripleStore HTTP/1.1
Host: www.myorg.org
Accept: application/rdf+xml
Range: xpointer = xmlns(x:http://www.mindswap.org)x:rdql(
SELECT (?x foaf:mbox ?mbox)
WHERE (?x foaf:name “John Smith”) (?x foaf:mbox ?mbox)
USING foaf FOR
)

The response looks as follows. The HTTP 206 (Partial Content) status code is used to indicate that the server recognized and processed the Range header and that the response entity includes only the identified logical range of the addressed resource.
HTTP/1.1 206 Partial Content
Content-Type: application/rdf+xml

For normal text (not markup), there are no special characters: just make sure your document refers to the correct encoding scheme for the language and/or writing system you want to use, and that your computer correctly stores the file using that encoding scheme. See the question on non-Latin characters for a longer explanation.
If your keyboard will not allow you to type the characters you want, or if you want to use characters outside the limits of the encoding scheme you have chosen, you can use a symbolic notation called ‘entity referencing’. Entity references can either be numeric, using the decimal or hexadecimal Unicode code point for the character (eg if your keyboard has no Euro symbol (€) you can type €); or they can be character, using an established name which you declare in your DTD (eg ) and then use as € in your document. If you are using a Schema, you must use the numeric form for all except the five below because Schemas have no way to make character entity declarations.
If you use XML with no DTD, then these five character entities are assumed to be predeclared, and you can use them without declaring them:
<
The less-than character (<) starts element markup (the first character of a start-tag or an end-tag).
&

The ampersand character (>) starts entity markup (the first character of a character entity reference).
>
The greater-than character (>) ends a start-tag or an end-tag.
"
The double-quote character (“) can be symbolised with this character entity reference when you need to embed a double-quote inside a string which is already double-quoted.
‘
The apostrophe or single-quote character (‘) can be symbolised with this character entity reference when you need to embed a single-quote or apostrophe inside a string which is already single-quoted.
If you are using a DTD then you must declare all the character entities you need to use (if any), including any of the five above that you plan on using (they cease to be predeclared if you use a DTD). If you are using a Schema, you must use the numeric form for all except the five above because Schemas have no way to make character entity declarations.

There are four possible results from this call:
‘kill()’ returns 0. This implies that a process exists with the given PID, and the system would allow you to send signals to it. It is system-dependent whether the process could be a zombie.
‘kill()’ returns -1, ‘errno == ESRCH’ either no process exists with the given PID, or security enhancements are causing the system to deny its existence. (On some systems, the process could be a zombie.)
‘kill()’ returns -1, ‘errno == EPERM’ the system would not allow you to kill the specified process. This means that either the process exists (again, it could be a zombie) or draconian security enhancements are present (e.g. your process is not allowed to send signals to *anybody*).
‘kill()’ returns -1, with some other value of ‘errno’ you are in trouble! The most-used technique is to assume that success or failure with ‘EPERM’ implies that the process exists, and any other error implies that it doesn’t.
An alternative exists, if you are writing specifically for a system (or all those systems) that provide a ‘/proc’ filesystem: checking for the existence of ‘/proc/PID’ may work.

A pipe is two or more commands separated by pipe char ‘|’. That tells the shell to arrange for the output of the preceding command to be passed as input to the following command.
Example : ls -l | pr
The output for a command ls is the standard input of pr.
When a sequence of commands are combined using pipe, then it is called pipeline.

With the help of kill command we can terminate the process.
Syntax: kill pid
Kill 0 – kills all processes in your system except the login shell.

Directing the flow of data to the file or from the file for input or output.
Example : ls > wc

Shell variables are special variables, a name-value pair created and maintained by the shell.
Example: PATH, HOME, MAIL and TERM

Use ‘su’ command. The system asks for password and when valid entry is made the user gains super user (admin) privileges.

Kernel checks ‘type’ field in the file’s inode structure.

Two prompts, PS1 (Primary Prompt), PS2 (Secondary Prompt).