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Unix
Unix is a family of operating systems primarily designed for servers, mainframes, and high-end workstations. First created in 1969, Unix systems are renowned for their security and stability.
1,127 Questions
End of line character in mainframe file?
The end of line character on an IBM mainframe is the newline character (same as it is on Ascii platforms). The value, however, is different. It is a hex 0x25 (EBCDIC)
What are the functions of line discipline in unix?
1. To parse input strings into lines.
2. To process erase characters.
3. To echo(write) received characters to terminal.
What is the Unix command to get the name of a process?
Use the 'PS' (process status) command to find out the name of the executable file for a process. If you use the long form and you know the process id, try:
PS -p process-id -l
or
PS -p process-id -f
What are the installation differences between Linux and Solaris?
Linux is generally easier to install today. I experienced considerable difficulty in my last attempted install of Solaris 10 on a SunBlade 150.
Can A file contain files directories and folders?
A file cannot (in general) contain other files or folders in the traditional sense. A zip or other archive file can contain other files or folders and a document file can have a file in it as an embedded object, but these are special applications.
Layers of UNIX Operation System along with an example to illustrate the interaction between shell and Kernel.
The UNIX operating system is made up of three parts: the kernel, the shell and the programs.
The kernel
The kernel of UNIX is the hub of the operating system: it allocates time and memory to programs and handles the filestore and communications in response to system calls.
The shell
The shell acts as an interface between the user and the kernel. The shell is a command line interpreter (CLI). It interprets the commands the user types in and arranges for them to be carried out. The commands are themselves programs: when they terminate, the shell gives the user another prompt ($ on our systems).
The programs
A program is refereed to as a process while the kernel is running it. The Kernel can run the same shell program(or any other program) simultaneously for many users on a Unix System, and each running copy of the program is a separate process. The Shell is also a program that the UNIX Kernel runs for the user.
As an illustration of the way that the shell and the kernel work together, suppose a user types rm myfile(which has the effect of removing the file myfile). The shell searches the filestore for the file containing the program rm, and then requests the kernel, through system calls, to execute the program rm on myfile. When the process rm myfile has finished running, the shell then returns the UNIX prompt $ to the user, indicating that it is waiting for further commands.
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What is the difference between Linux and Unix?
To put it very generically, Linux is an operating system kernel, and UNIX is a certification for operating systems. The UNIX standard evolved from the original Unix system developed at Bell Labs. After Unix System V, it ceased to be developed as a single operating system, and was instead developed by various competing companies, such as Solaris (from Sun Microsystems), AIX (from IBM), HP-UX (from Hewlett-Packard), and IRIX (from Silicon Graphics). UNIX is a specification for baseline interoperability between these systems, even though there are many major architectural differences between them. Linux has never been certified as being a version of UNIX, so it is described as being "Unix-like." A comprehensive list of differences between Linux and "UNIX" isn't possible, because there are several completely different "UNIX" systems.
What is the parent process ID of an orphan process in UNIX?
Usually any orphaned process is owned by the 'init' process (process #1)
How does Unix facilitate the installation of a new device without recompiling the OS?
This is done via a technique known as a loadable driver; the actual hardware driver is loaded into the system dynamically. Since devices can be loaded and unloaded they do not have to be compiled into the system kernel.
How do you zip files in Terminal or Unix on Mac OS 10.2?
To zip just one file (file.txt) to a zipfile (zipfile.zip), type the following: zip zipfile.zip file.txt To zip an entire directory: zip -r zipfile.zip directory For more advanced options, check the man page of zip: man zip
What is basic bare machine in operating system?
Basic Machine, in computer parlance, means a computer without its operating system. Modern operating systems evolved through various stages, from elementary to the present day complex, highly sensitive real-time systems. In the very first stage of computing there was nothing like an Operating System at all. Programs were fed to the computer system directly using machine language by the programmers without any system software support. This approach is termed the "Bare Machine" approach in the development of operating systems.
What happens in unix if you run the command init 1?
If you are not the administrative user, nothing will happen. For some systems, a priviledged user can issue this command or 'telinit' or some variant of that to place the system runlevel in what is known as "single user" state.
This state is commonly used for maintenance or diagnostic purposes and does not allow multiple users or certain background services to execute.
Why operating system is called resource manager?
operating system is the system software .operating system is communicate with the hardware .so it provide space & cpu time etc to the proceeses performed by the os
What is the boot sequence of an HP-UX system?
1] Poweron.
2] PDC Activates and checks for CPU and memory and other peripheral connected to it.
3] Checks if AUTOBOOT Flag is on. If yes , its try to locate the Primary boot path.
4] And loads Initial system loader , from Primary boot path.
5] ISL Loads the secondery loader called hp-ux.
6] hpux loads the kernel /stand/vmunix
7] kernel starts first process swapper , and then init
8] Shell /sbin/pre_init_rc executes .
9] init locates /etc/inittab
10] /etc/inittab starts the system the default run level , mentioned with "initdefault" parameter.
11] Then executes /sbin/bcheckrc and activates LVM ,
it does following :
1) activates LVM (if appplicable).
# 2) runs eisa_config in automatic mode
# (if applicable).
# 3) checks the file systems before mounting.
# (the scripts required for file system specific
# checking reside in /sbin/fs/
# 4) and anything else that should be done before
# mounting any file systems.
------------------
It checks for the file /sbin/lvmrc and , /etc/lvmrc activates the LVM , if AUTO_VG_ACTIVATE=1 mentioned.
12 ]Then it spawns getty process ,
cons:123456:respawn:/usr/sbin/getty console console
And it gives login : prompt.
Raj
What is path variable and what is its use?
The path (or PATH) variable is a shell environment variable. It describes to the shell which directories should be searched for executable files/programs. The system does not search every directory to find a program; only those directories indicated in the PATH shell environment variable. The same thing is true for Windows.
How do you program a calculator in UNIX using shell programming?
do(
echo"welcome to calculator press x to exit"
echo"enter 1st no:"
read a
echo"enter operator(+,-,*,/,%):"
read o
echo "enter 2nd no:"
read b
if["$o"="+"];
then
ans=($a+$b);
if["$o"="-"];
then
ans=($a-$b);
if["$o"="*"];
then
ans=($a*$b);
if["$o"="/"];
then
ans=($a/$b);
if["$o"="%"];
then
ans=($a%$b);
)while[$!='x']
echo "answer is:$ans";
done
The most powerful level of UNIX accounts is called?
The account in Unix that has the most power is the administrative account 'root'. It can do anything on the system.
Explain unix shell scripting commands in detail?
This depends widely on the actual shell environment you are using. I suggest you take a look at the YouTube videos, which cover the various scripting elements in detail.
How are unix and Linux related?
Unix and windows are two separate groups of operating systems. Windows is the operating system of about 90% of personal computers, while unix is the basis of many other operating systems, such as Mac OS X
UNIX initially did not include a graphical interface?
Very true - the X-windows graphical interface was not available in Unix systems for a long time after Unix was available.
How do you write a shell script to perform arithmetic operation such as input1234 and output10?
Use "bc". For example:-
[irb@eddie ~]$ echo "1 + 2 + 3 + 4" | bc
10
[irb@eddie ~]$
Use "man bc" to learn more about this calculator program.
Which protocol is used to transfer files between Unix and Linux systems?
There are several protocols that could be used, depending on how you wanted to transfer the file. There are, for example:
- FTP - file transfer protocol
- TFTP - trivial file transfer protocol
- NFS - Network file system transfer
- SMTP - via email
- rcp - remote copy protocol
- SFTP - Secure File Transfer Protocol
- scp - secure copy
The sticky bit will prevent a user from deleting other user's files in a world writeable directory (such as /tmp). Otherwise, any user could delete any other user's files.
Program in shell of implementing cp command?
The 'cp' command is a primitive command; there isn't anything really in the shell to accomplish this. You could use other commands for 'cp' (such as 'cat') but those are also primitive commands.
