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How to terminate a process which is running and the specialty on command kill 0?
With the help of kill command we can terminate the process.Syntax: kill pidKill 0 - kills all processes in your system except the login shell.
satyam.kumar2008
- Aug 9th, 2008
Kill -0 : All processes in the current process group are signaled. Kill -0 commnd is use to sends signal to all process and group of process.
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What is a pipe and give an example?
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 | prThe 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.
satyam.kumar2008
- Aug 9th, 2008
The Unix commands alone are powerful, but when two or more commands get combine together, we can accomplish complex task with ease.In unix we can combine the two or more commands together to perform m...
wow_suraj
- May 7th, 2008
Pipe '|' is used to combine two or more commands to be executed at the sameinstance.Pipe redirects output of the first command (before '|') as input to the second comman...
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What is redirection?
Directing the flow of data to the file or from the file for input or output.Example : ls > wc
satyam.kumar2008
- Aug 9th, 2008
Whenever we run a command on shell prompt we get some output on shell prompt.In case we don't want to appear the output on the shell prompt we can redirect the output to the somewhere else. We can mak...
wow_suraj
- May 7th, 2008
redirection is used to change the default input and output source.'>' is used to redirect the output to location other than standard output terminal. If the location doesn't exist it wi...
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What is Process Control board in UNIX?
parthvora18
- Aug 20th, 2008
Process Control Block in Unix is a data structure which is used to mange Processes. It contains following:1. PID2. Pointer to the next PCB3. Register Values4. Priority5. I/O information6. Process accounting information. 7. Adress Space.
Rakesh
- Sep 13th, 2006
I heared about the Process control block. Which will store the Pids od the processes in the system. But Process control board?? Is some thing like that exists??? Not sure!!!
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How to read error messages in /var/adm/messages when system is not booting?
Rambo188
- Aug 23rd, 2008
If OS can't boot into multi-user level, I can try to boot the OS into single-user level.If I can't boot into single-user level, I wouldn't read the messages in /var/adm/messages.
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Explain design philosophy of UNIX operating system and explain the mechanism of inter process communication and synchronisation.
rajanikanth.ha
- Aug 26th, 2008
The inter process communication is a way of communication between the processes. In UNIX these are achieved through pipes (named & unnamed pipes), semaphores, message queues, shared memory.
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Why is the . not included in the path?
nayakss
- Dec 10th, 2008
I don't think there is any hard and fast rule that not to include "." in the Path variable. If you need it, then you can add and add the . at the end. Like /usr/sbin:/sbin:/usr/etc:.
Rhishikesh
- Feb 16th, 2007
Yes, . means current working directory and having current directory into your path could create problem like.. I can have 'ls' command written in current directory to delete all the files
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Where is kernel located in HP unix?
Jitendra Katiyar
- Jan 3rd, 2007
It is inside /stand directory with name of "vmunix".
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What is semaphore?What is Monitor?
bsmanyan
- Jan 29th, 2009
A hardware or software flag. In multitasking systems, a semaphore is a variable with a value that indicates the status of a common resource. It's used to lock the resource that is being used. A pr...
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Open Source
What is the meaning of open source? How it is associated with the meaning of heavily documented?
siddharthb
- Apr 29th, 2009
Yes and Open Source Software refers to provision of source code for customization as per your need, for which good documentation is essential.Also Detailed documentation about licencing type is expected to be included.eg, GPLv2, GPLv3, Apache common Licence etc ...
mahendraselvi
- Jan 23rd, 2009
Computer software for which the source code is freely available .You can customize as per you needs.
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What is meant by u-area? Where it resides? What does it contain?
akki1af1
- May 21st, 2009
Every process has a private u area, yet the kernel acesses it as if there were only one u area in the system, that of the running process. The kernel changes its virtual address translation map accord...
gthosani1
- Dec 19th, 2007
The u area. In addition to the text, data, and stack segment, the OS also maintains for each process a region called the u area (User Area). The u area contains information specific to the process (e...
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How to find some particular lines in unix Vi editor which starts with a particular word and end with another particular word?? For ex - There are 10 lines in the editor and only 4 lines start with the word APPLE and end with the word MANGO.Now how to find out these particular lines in Unix?
Orions
- Dec 28th, 2006
'esc` then :/word-to-find then `enter`
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Hello does anyone know how to do the following using some simple unix if possible:I have a file with the following info as comma separated. It shows username, id number and what subjects they are enrolled in. The subjects are separated by colons. UserName,ID,Subjectjsmith,235456939,MATH29879:PHYS45979jdoe,750378929,ENGL36899:JAPN92576I want it to have one username with one course per line. So that it would look like:jsmith,235456939,MATH29879jsmith,235456939,PHYS45979jdoe,750378929,ENGL36899jdoe,750378929,JAPN92576Does anyone have any ideas?Thnx-J
ppravinreddy
- Aug 30th, 2007
use below command:$ cat t.txtjsmith,235456939,MATH29879:PHYS45979jdoe,750378929,ENGL36899:JAPN92576$ cat t.txt|sed "s/:/,/g"|awk -F"," '{OFS=","; print $1,$2,$3;print...
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How do you mount Linux partition on windows
tonan
- Jul 3rd, 2009
In order to mount LINUX partitions on Windows, you need to use a third party software, Windows does not provide any inbuilt utility for this. Unlike "mount" in UNIX/LINUX Windows does not provide you with a utility to access any other file system.
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Difference - Loading and Linking?
harsha419
- Jul 7th, 2009
A linker takes several object files and libraries as input and produces one executable object file (or) Linking is simply the process of placing the address of a called function into the calling funct...
abhishek
- Jan 2nd, 2007
Load -> Puts the CSECT(smallest executable unit) into main memory.Linking is a different cup of tea, this is done to make a module executable.The only way you can draw a relation between is wh...
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UNIX Password change issue
Hi,While trying to change the password of a normal user [ I logged in as root], I am getting the following message :-[root@localhost root]# passwd someuserChanging password for user someuser.passwd: Authentication information cannot be recovered[root@localhost root]#-------------------Think there's some issue in PAM configuration for password policy, please guide me for the same. Its urgent. Thanks...
dgangadharn09
- Jul 11th, 2009
You can use the following command to change the password.Sudo chpasswd -cusername:passwordpress ctrl+d
vishpri
- Apr 16th, 2008
Run pwdck command at the command line.this command will ensure the consistency with all the user authentication files like1. /etc/security/passwd2. /etc/passwd3. /etc/security/login.cfg4. /etc/security/user
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What is relative path and absolute path?
Absolute path : Exact path from root directory.Relative path : Relative to the current path.
mmakoko
- Jul 25th, 2009
Absolute path: Exact path from root directory to the target directory.Relative path: Path for current directory to target directory.
shyam82
- Apr 21st, 2009
Relative path name is relative to current directory. Following notations are very heplful.1* denotes current directory2** denotes parent directoryAbsolute path name is full path name. Each directory a...
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What is the command to view the active vg?
richa.saxena83
- Jul 28th, 2009
HPUX:# vgdisplay If the VG is ACTIVE, you will get the output else an error message "vg not active".-RK
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Extracting File Name
How can you extract just the Filename from the Fully Qualified Path and Filename.Basename?
jincee
- Aug 10th, 2009
file1=`basename $0`echo "$file1"(or)file1=`basename /home/user1/Jincy/base.ksh`echo $file1 The above commands will give the outpuy as base.ksh if you just need the base of the file...
arunkumj
- Jan 15th, 2009
Cat will give the full content of a file in one go.more will give the content of the file in page by page
UNIX Interview Questions
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