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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
SHA is cryptographic hash function used to encrypt passwords.
The SHA hashing algorithm is not restricted to Unix, though. It is typically used to verify the integrity of some downloaded file, to make sure there was no corruption during transmission. Your Windows or OSX software may use this same algorithm without you knowing it.
List and execute UNIX command to display the number of words in the last 10 lines of any file?
tail -10 anyfile | wc
The awk programming/scripting language is used to pattern match text and then do something with the result. Using the -f option indicates that the awk program/script has been stored in an external file instead of being specified inline with the command.
What is meant when it is said a file is structureless in Unix?
Structureless files - There is no internal structure imposed on the contents of a file. Any structure desired by the user can be used.
How do you clear a search history in ubuntu Linux?
I figure you are talking about firefox internet browser? To clear history,open firefox, go to tools>Clear Recent History, and select how long (everything reccommended). click clear, and your all set
How do you change the upercase to lower or lower to upercase in unix?
There are many different ways of doing this. If you are asking about the content of a file, use the 'tr' (translate) command. The actual parameters may vary from system to system, so use the 'man tr' command to be sure.
For example, you may be able to change from lower to upper case by:
tr '[a-z]' '[A-Z]' < infile > outfile
What job functions could you script in a UNIX or DOS shell script?
Actually, just about anything you want to do. Depends on the job function requirements.
What is the difference between ls and vdir command in Unix?
ls is the default command that lists the contents of a directory.
vdir is a common alias for the command: ls -al
That command lists the contents of a directory as well as information about the file such as owner, group, file size, permissions, last modified, etc.
What is the command to get the Unix version?
cat /proc/version
The above answer will only work on certain systems. For most Unix systems, use the 'uname' command to get the Unix version.
AIX uses the oslevel command.
How do you display the permissions for a file or directory?
Use the 'ls' command with the long listing option:
ls -l
What is a secondary prompt in UNIX?
The secondary prompt (PS2) is used to prompt the user with whatever string they want to indicate a command continuation line. For example, if I use the standard PS2 prompt and type in the command:
cat abc def \
The shell will prompt me for the rest of the line with a ? mark or some other character. I usually set my secondary prompt for something more interesting, such as:
PS2='more ? '
So that I know that the shell wants more information before executing the command line.
What do four ampersands all strung together mean in a UNIX command string?
4 ampersands together is not legal for Unix/Linux.
What is the command that will change the current default directory to the root directory in Unix?
CD /
Why to use putty and is there any difference between unix and putty?
putty is an application program; Unix is an operating system (they aren't the same thing).
putty is a secure telnet replacement using ssh to encrypt the data transmission flow.
How do you mount a drive in Unix?
In order to mount a drive, if it is a network drive, you must have an NFS server installed and an NFS client on the machine you wish to mount the directory for.
The NFS server will export the file system to the network, and the NFS client machine will mount it.
To mount it on a client machine, create or use an empty directory. Then, using the 'mount' command, indicate the server name and directory on the server and the mount point of the client. For example:
mount tarzan:/opt/testing/data /mnt
Will mount a directory from the 'tarzan' server called /opt/testing/data under the /mnt directory of the client. So when a client looks at /mnt, they are really looking at /opt/testing/data on the server.
How do you configure Network File System server?
There are many different ways of configuring NFS depending on your environment and security requirements. Too many to list here in a short answer. Configuration is usually specific to a site and their requirements.
While I'm not familiar with any Unix OS that creates files named core.dmp (Unix systems do not typically use 3 letter suffixes), I can speak to the file commonly called just "core". This file gets created when an application performs an illegal activity, such as referencing an address outside its address space or dividing by zero. Illegal activities result in a synchronous signal being sent to the offending process. Unless handled, the typical result is for an image of the process to be saved to the file called "core". Tools such as "gdb" or "adb" can be used to examine the core file in order to determine what the process was doing that caused it to receive the signal. However, unless the process was compiled with debug information (e.g., -g) and linked with symbols intact, there's precious little that can be deduced. If the process has no symbols nor debug information, the simplest thing to do is to use the "file" command: file core in order to view an abbreviated description (name of the process and the signal that terminated the process). For more information, see the signal(2) and signal(5) man pages on any decent Unix system. (p.s. I speak from 25 years as a Unix developer.)
AnswerCORE DUMP are images of application failure messages during there execution in LINUX/UNIX they give little clue about what happened to that particular application while run. Cause of application failure may be anything e.g. memory violation ,not enough memory or anything that makes an application to stop run. For further refrences please refer to the System Administration Handbook on LINUX that comes from different writers but one that I have read is by Nemeith . Any even I can suggest you more at rupesh_joshi@sify.com rupesh.joshi@gmail.com Rupesh Kumar Joshi India AnswerThis response is anecdotal but may also be informative. In the early 1990s we operated a 3 processor Unix server which one day had what is known as a kernel panic. When a Unix kernel panics, it attempts to write out a core dump containing the state of the CPU registers and memory at the time of the panic. Typically, the Unix or Linux crash utility or program is then used on the core dump to help in determining the cause of the panic.
Unfortunately, since we discovered that our server was experiencing a second kernel panic while in the process of writing it's core dump from it's first kernel panic, the core dump failed and was not properly written out to disk thus using the crash utility was not possible. Eventually, the problem was identified as a failed CPU and, after replacing the failed CPU, all kernel panics stopped and the server ran normally. Had our kernel not panicked while experiencing a kernel panic, we would have been able to use the core dump to determine the cause of the kernel panic by using the crashprogram to analyze the core dump.
Write a shell program to check read and write permissions of a file?
You don't say what you want to do with the permissions, but most shells have a 'test' command that can look at various permissions. Look at the 'man' command for the shell you are running in to see what tests are possible on files and directories.
You can check to see if the target is a directory, or a file, and whether it has read, write, or execute/search permissions. Again, it varies by the shell environment.
What is the old version of the lottery called?
the old version of the lottery is called lottery and the new version is called lotto
It is not a bad way to remove Unix thru Windows Add/Remove Programs list.1. Go to the Start Menu on the bottom left of your computer's screen.
2. Locate and click on Control Panel.
3. Find the Add or Remove Programs icon and double-click it.
4. Here you'll see a whole list of programs & applications that are installed on your computer. Find and select Unix and click "Uninstall".
5. Confirm that you want to uninstall Unix by clicking on "Remove".
How do you create user in redhat?
Use the useradd command. By default, this will add a user and create a home dircetory for that user, which will be located in /home.
EXAMPLE: /usr/sbin/useradd yourname will create the user yourname, and make the directory /home/yourname
Set the password for the new user by running passwd. This will give the user a password and activate the account.
EXAMPLE: /usr/bin/passwd yourname. You will be prompted twice for a password.
In Unix how to remove a directory that is not empty?
The easiest way is to use the 'rm' command recursively. For example, the command:
rm -rf /data/test/docs/fall
would remove the directory 'fall' from /data/test/docs, even if it isn't empty.
