Give the brief about AIX.- AIX is the IBM product.
- It is the multi user Operating System.
- AIX control these hardware devices and to share them between multiple users, for this purpose it uses the AIX Kernel System.
- AIX OS servers are the IBM servers used in all over the world.
- Kernel is loaded during the system startup.
- Kernel is the heart of the AIX OS.
- Kernel controls the various processes and tasks.
Explain the login process to the AIX system.- AIX is a multi-user system
- When the user login he needs to provide the user name and password for authentication purposes.
- After the successful login, AIX starts the SHELL program.
Explain the SHELL program.- As the user login to the AIX server, the AIX starts the SHELL program.
- The SHELL is a command interpreter.
- It takes the inputs from the users and executes it.
- SHELL is not only the command interpreter it also provide great flexibility to the user.
- SHELL not only read and execute the commands it also read the files written in the form of programs and executes them, these shell program files are known as SHELL scripts. The extension of SHELL script is .sh.
Name the various SHELL types.- sh or Bourne Shell
- bash or Bourne Again shell
- csh or C shell
- tcsh or Turbo C shell
- ksh or the Korn shell
List the advantages of Bourne Again Shell or bash.- Bash is the GNU shell
- Bash is an sh-compatible shell that incorporates useful features from the Korn shell (ksh) and C shell (csh).
- It is intended to conform to the IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools standard.
- It offers functional improvements over sh for both programming and interactive uses.
- Interactive usage includes command line editing, unlimited size command history, job control, shell functions and aliases, indexed arrays of unlimited size, and integer arithmetic in any base from two to sixty-four. Bash can run most sh scripts without modification.
What is an interactive shell?An interactive shell generally reads from, and writes to, a user's terminal: input and output are connected to a terminal. Bash interactive behavior is started when the bash command is called upon without non-option arguments, except when the option is a string to read from or when the shell is invoked to read from standard input, which allows for positional parameters to be set.
Explain the AIX file system.- AIX uses a hierarchical file tree that consists of directories, subdirectories and files.
- The top level directory is called the root (/) directory that has many subdirectories.
- The file tree is mounted during the system startup.
Write the logging in and Out commands in AIX.- To login in:
Login id: <username>
Password: <the password does not appear>
- To log out:
$ <ctrl+d> (or)
$ <exit> (or)
- AIX is designed as a multiuser system, a level of security is implemented to control access. Each user of the system has a user name and associated password (optional).
- If the user ID requires a password, the system will prompt for the password in a similar manner. While the user is typing a password, it does not appear on the screen.
- To terminate the session the user may either enter the exit or logout command, or press the key combination (holding down the Ctrl key while pressing the d key.) logout only works if you are in your login shell.
Write the password change command.- $ passwd
$ <user id> old password:
$ <user id> new password:
$ Enter the new password again:
- The passwd command is used to change the user password.
- The system will start the passwd process which will prompt the user for their old password first. To prevent users being locked out of the system the new password is entered twice.
Write the command format in AIX format.- $ command option(s) argument(s)
- Mail –f newmail
- The command or process name should come first.
- The options should follow the command name, separated by a space, and preceded by a minus sign (-). Multiple options may be grouped immediately after a single minus sign or separated by spaces and each preceded by a minus sign.
Write the date and calendar command.- $ date
- $ cal
- $ cal 2003 (looking in a year)
- $ cal 1 2003(looking in a month)
Write clear, echo, print and banner command.- Clear: clears the terminal signal
- echo : Writes what follows to the screen.
$ echo Lunch is at 12:00
Lunch is at 12:00
- Banner : Writes character strings in large letters to the screen
$ banner Hello
$ print Lunch is at 12:00
Lunch is at 12:00
Write the key board shortcuts used on AIX terminal.- Backspace : to correct mistakes.
- <ctrl+c> : terminates the correct command and return to the shell.\
- <ctrl+d> : end of transmission or end of file
- <ctrl+s> : temporary stops the output to the screen
- <ctrl+q> : resumes output which was stopped by ctrl+s
- <ctrl+u> : erases the entire line.
Give the brief about man command.The man command will look in the on-line manual for information on the commands, subroutines and files with the name title. This information will be presented on the screen one page at a time for the user to browse.
The information consists of:
- PURPOSE : The title and a one-line description of the command
- SYNTAX : The syntax of the command
- DESCRIPTION : Many pages of information about the function and usage of the command with examples
- FLAGS : Description of available options
- FILES : Any system files associated with the command
- RELATED INFO : The names of any related commands
- BUGS : Any information about the behavior/performance of the command in unusual circumstances $ man <command for which you want the information>
Explain the file types in AIXA file is a collection of data, stream of characters or a byte stream. No structure is imposed on the file by OS. The various file types are as follows:
- Ordinary (text or code data)
- Directory (table of contents, that stores a list of files within that directory)
- Special files(representing hardware or logical devices)
An ordinary file can contain either text or code data. Text files are readable by a user and
can be displayed or printed. Code data, also known as a binary file is readable by the
computer. Binary files may be executable. Directories contain information the system needs to access all types of files, but they do not contain the actual data. Each directory entry represents either a file or a subdirectory.Special files usually represent devices used by the system.