Do You Know ?

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PS2 variable
A shell variable whose content is usually the > character. The contents of the PS2 variable is displayed by the shell as a secondary prompt that indicates the previous command was not complete and the current command line is a continuation of that command line.

pwd
The pwd command prints the absolute path of the current directory.

quoting
Literally, to enclose selected text within some type of quotation marks. When applied to shell commands, quoting means to disable shell interpretation of special characters by enclosing the character within single or double quotes or by escaping the character.

read permission
The read permission of a file or directory determines which users can view the contents of that file or directory.

regular expression
A string that can describe several sequences of characters.

regular file
The most common type of files you will encounter. These files store any kind of data. This data may be stored in plain text, an application-specific format, or a special binary format that the system can execute.

relative path
Relative pathnames let you access files and directories by specifying a path to that file or directory relative to your current directory.

remainder function
The remainder of a division operation, which is the amount that is left over and thus not evenly divisible.

reserved word
A nonquoted word that is used in grouping commands or selectively executing them, such as: if, then, else, elif, fi, case, esac, for, while, until, do, or done.

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rm
The command used to remove files.
scalar variable
A scalar variable can hold only one value at a time.

sed
The sed command is a stream editor that allows you to modify input lines using regular expressions.

set group ID (SGID)
The SGID permission causes a script to run with its group set to the group of the script, rather than the group of the user who started it.

set user ID (SUID)
The SUID permission causes a script to run as the user who is the owner of the script, rather than the user who started it.

shell
Provides you with an interface to the UNIX system. It gathers input from you and executes programs based on that input. After a program has finished executing, the shell displays that program’s output. The shell is sometimes called a command interpreter. See also bash, Bourne shell, C shell, Korn shell, and tcsh.

shell initialization
After a shell is started it undergoes a phase called initialization to set up some important parameters. This is usually a two step process that involves the shell reading the files /etc/profile and .profile.

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shell or command prompt
The single character or set of characters that the UNIX shell displays for which a user can enter a command or set of commands.

shell preprocessing
This describes actions taken by the shell to manipulate the command line before executing it. This is when filename, variable, command, and arithmetic substitution occur (as covered in Chapter 8, “Substitution”).

shell script
A program written using a shell programming language like those supported by Bourne, Korn, or C shells. In general, a script contains a list of commands that are executed noninteractively by the shell.

shell variable
A special variable that is set by the shell and is required by the shell in order function correctly.

signal
Software interrupts sent to a program to indicate that an important event has occurred. The events can vary from user requests to illegal memory access errors. Some signals, like the interrupt signal, indicate that a user has asked the program to do something that is not in the usual flow of control.

signal handler
A function that executes when a signal is received by a shell script. Usually signal handlers clean up temporary files and then exit.

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simple command
A simple command is a command that you can execute by just giving its name at the prompt.

socket file
A special file for interacting with the network via the UNIX file system.

STDERR
Standard error. A special type of output used for error messages. The file descriptor for STDERR is 2.

STDIN
Standard input. User input is read from STDIN. The file descriptor for STDIN is 0.

STDOUT
Standard output. The output of scripts is usually to STDOUT. The file descriptor for STDOUT is 1.

subdirectory
A directory that is contained within another directory.

subprocess
Process running under the control of another, often referred to as the parent process. See process.

subshell
Shell running under the control of another, often referred to as the parent shell (typically the login shell). See shell.

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symbolic link or soft link
A special filetype which is a small pointer file allowing multiple names for the same file. Unlike hard links, symbolic links can be made for directories and can be made across filesystems. Commands that access the file being pointed to are said to follow the symbolic link. Commands that access the link itself do not follow the symbolic link.

system call
A C language function that is used to request services from the UNIX kernel.

tcsh
A C shell–like user interface featuring command-line editing.

uninitialized shell
When a shell is started it is uninitialized. This means that important parameters required by the shell to function correctly are not defined.

usage statement
A statement issued by a shell script when one or more of its arguments are improperly specified.

utility
Utilities are programs, such as who and date, you can run or execute.

variable substitution
The process used by the shell to substitute the value of a variable, when the variable’s name is specified.

wc
The command used to count the words, lines and characters in a file.

word
An unbroken set of characters. The shell uses spaces and tabs to separate words.

write permission
Controls the users who can modify a file.

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For help, type 'help' at DOS prompt

C:\Docu\Service>help

For more information on a specific command, type HELP command-name
ASSOC Displays or modifies file extension associations.
ATTRIB Displays or changes file attributes.
BREAK Sets or clears extended CTRL+C checking.
BOOTCFG Sets properties in boot.ini file to control boot loading.
CACLS Displays or modifies access control lists (ACLs) of files.
CALL Calls one batch program from another.
CD Displays the name of or changes the current directory.
CHCP Displays or sets the active code page number.
CHDIR Displays the name of or changes the current directory.
CHKDSK Checks a disk and displays a status report.
CHKNTFS Displays or modifies the checking of disk at boot time.
CLS Clears the screen.
CMD Starts a new instance of the Windows command interpreter.
COLOR Sets the default console foreground and background colors.
COMP Compares the contents of two files or sets of files.
COMPACT Displays or alters the compression of files on NTFS partitions.
CONVERT Converts FAT volumes to NTFS. You cannot convert the
current drive.
COPY Copies one or more files to another location.
DATE Displays or sets the date.
DEL Deletes one or more files.
DIR Displays a list of files and subdirectories in a directory.
DISKCOMP Compares the contents of two floppy disks.
DISKCOPY Copies the contents of one floppy disk to another.
DISKPART Displays or configures Disk Partition properties.
DOSKEY Edits command lines, recalls Windows commands, and
creates macros.
DRIVERQUERY Displays current device driver status and properties.
ECHO Displays messages, or turns command echoing on or off.
ENDLOCAL Ends localization of environment changes in a batch file.
ERASE Deletes one or more files.
EVENTQUERY Displays event log entries for specified criteria.
EXIT Quits the CMD.EXE program (command interpreter).
FC Compares two files or sets of files, and displays the
differences between them.
FIND Searches for a text string in a file or files.
FINDSTR Searches for strings in files.
FOR Runs a specified command for each file in a set of files.
FORMAT Formats a disk for use with Windows.
FSUTIL Displays or configures the file system properties.
FTYPE Displays or modifies file types used in file extension
associations.
GOTO Directs the Windows command interpreter to a labeled line in
a batch program.
GPRESULT Displays Group Policy information for machine or user.
GRAFTABL Enables Windows to display an extended character set in
graphics mode.
HELP Provides Help information for Windows commands.
IF Performs conditional processing in batch programs.
LABEL Creates, changes, or deletes the volume label of a disk.
MD Creates a directory.
MKDIR Creates a directory.
MODE Configures a system device.
MORE Displays output one screen at a time.
MOVE Moves one or more files from one directory to another
directory.
OPENFILES Displays files opened by remote users for a file share.
PAGEFILECONFIG Displays or configures Pagefile properties.
PATH Displays or sets a search path for executable files.
PAUSE Suspends processing of a batch file and displays a message.
POPD Restores the previous value of the current directory saved by
PUSHD.
PRINT Prints a text file.
PROMPT Changes the Windows command prompt.
PUSHD Saves the current directory then changes it.
RD Removes a directory.
RECOVER Recovers readable information from a bad or defective disk.
REM Records comments (remarks) in batch files or CONFIG.SYS.
REN Renames a file or files.
RENAME Renames a file or files.
REPLACE Replaces files.
RMDIR Removes a directory.
SET Displays, sets, or removes Windows environment variables.
SETLOCAL Begins localization of environment changes in a batch file.
SC Displays or configures services (background processes).
SCHTASKS Schedules commands and programs to run on a computer.
SHIFT Shifts the position of replaceable parameters in batch files.
SHUTDOWN Allows proper local or remote shutdown of machine.
SORT Sorts input.
START Starts a separate window to run a specified program or command.
SUBST Associates a path with a drive letter.
SYSTEMINFO Displays machine specific properties and configuration.
TASKLIST Displays all currently running tasks including services.
TASKKILL Kill or stop a running process or application.
TIME Displays or sets the system time.
TITLE Sets the window title for a CMD.EXE session.
TREE Graphically displays the directory structure of a drive or
path.
TYPE Displays the contents of a text file.
VER Displays the Windows version.
VERIFY Tells Windows whether to verify that your files are written
correctly to a disk.
VOL Displays a disk volume label and serial number.
XCOPY Copies files and directory trees.
WMIC Displays WMI information inside interactive command shell.

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Help at Dos prompt

E:\Documents and Settings\Administrator>help help
Provides help information for Windows commands.

HELP [command]

command - displays help information on that command.

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Information About ping commannd

At DOS prompt type ping/?
E:\Documents and Settings\Administrator>ping/?

Usage: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]
[-r count] [-s count] [[-j host-list] | [-k host-list]]
[-w timeout] [-R] [-S srcaddr] [-4] [-6] target_name

Options:
-t Ping the specified host until stopped.
To see statistics and continue - type Control-Break;
To stop - type Control-C.
-a Resolve addresses to hostnames.
-n count Number of echo requests to send.
-l size Send buffer size.
-f Set Don't Fragment flag in packet (IPv4-only).
-i TTL Time To Live.
-v TOS Type Of Service (IPv4-only).
-r count Record route for count hops (IPv4-only).
-s count Timestamp for count hops (IPv4-only).
-j host-list Loose source route along host-list (IPv4-only).
-k host-list Strict source route along host-list (IPv4-only).
-w timeout Timeout in milliseconds to wait for each reply.
-R Trace round-trip path (IPv6-only).
-S srcaddr Source address to use (IPv6-only).
-4 Force using IPv4.
-6 Force using IPv6.

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AJAX stands for Asynchronous JavaScript and XML. It's a development technique that mixes (X)HTML, JavaScript, CSS, DOM, XML and XSLT to create interactive Web applications.Apache is one of the the world's most widely used Web servers. Originally developed in 1995 by a group that was to go on to become the The Apache Group, the Apache HTTP Server is Open Source Software, and considered by proponents to be fast, scalable and secure.

Active Server Pages - Microsoft's IIS based server side scripting architecture. ASP is a gateway for scripting languages such as VBScript and JScript.

Cache, pronounced "cash", refers to a stored copy of (or pointers to) previously accessed data in fast SRAM memory.

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Cascading Style Sheets for a set of formatting rules interpreted by the Web browser (or other client) that may contain the styling and formatting information intended for the presentation of a Web page. The W3C recommends the use of CSS to help keep Web content (HTML/XHTML) separate from its formatting information.

A Domain Name Server (DNS) is a distributed network of servers where host names are translated to their IP addresses.

IP address is the unique numeric identifier of every computer connected to the Internet. Each IP address consists of a four number pattern separated by periods (XX.XX.XX.XX). Each number must be between 0 - 255.

Localhost is an alias for the address 127.0.0.1, an address that always indicates the local computer.