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Unix OS





Unix is a multitasking, multi-user computer operating system originally developed in 1969 at Bell Labs. Today, it is a modern OS with many commercial flavors and licensees, including FreeBSD, Hewlett-Packard’s UX, IBM AIX and Apple Mac OS-X. Apart from its command-line interface, most UNIX variations support the standardized X Window System for GUIs, with the exception of the Mac OS, which uses a proprietary system.

on my windows 10 machine after installing oracle virtua box and centos on top of it while starting getting below error

Failed to open a session for the virtual machine centos.

The virtual machine 'centos' has terminated unexpectedly during startup with exit code 1 (0x1).  More details may be available in 'C:\Users\saiganesh\VirtualBox VMs\centos\Logs\VBoxHardening.log'.

Result Code: E_FAIL (0x80004005)
Component: MachineWrap
Interface: IMachine {b2547866-a0a1-4391-8b86-6952d82efaa0}

i tried on other laptop i do not see red hat 64 some reason but shows red hat 32 bit

Please advise
how to remember shell history and how to save unix queries for future use and share with the team

$HISTSIZE can be increased to unlimited size?

how to type attached l character

please advise
how below commands are different

su department (when i do pwd here says department)
su - department(when i do pwd here says /home/department)

when i do below

su -c 'echo $echo  $DEPARTMENT_HOME' department
it does not work

when i do below

su -c 'echo $echo  $DEPARTMENT_HOME'  - department
it does work. Please advise the difference.

what is difference between
department and  /home/department

how su and sudo are different?

how can there is depearment inside home as well as outside at top level again?

what is visudo and sudoers file or folder?

Please advise
difference between below process killing signals

kill -15 123


kill -TERM 123

kill -9 123

how foreground and background processes are different and how to kill or suspend them?
is PID is always 4 digit or it can be 10 digit etc?

how job and process different?
how to distinguish between background and foreground jobs?

when i say

it simply shows 5 different jobs one with + other with -

but does not show whether background or foreground?

i have a job running in background i brought it to foreground and stopped it.
when i moved it again to background it automatically moved to RUNNING status? how this is possible?
how terminated suspended and killed etc are different?
Please advise
What percent use Windows versus Mac versus other?

I am curious to see the difference...

$ emacs xyz.log
-bash: emacs: command not found

i am getting above error.

how to install and use emacs.

vi is better or emacs is better to use?

what is
meta D means
how it is different from control D

please advise on advantages, disadvantages of each
how to install and use nano editor

$ nano
-bash: nano: command not found

I get above error.

Please advise
what are differences, advantages, disadvantages of octal decimal binary symbolic rwx and all  permissions to user, group, other
while adding modifying setting permissions
when we use umask?

Please advise
what is meaning of  below command in unix
$echo $PATH
i got output like

what is meaing of :

why it shows bin and sbin so many times
what is usr and local here and what is root and how that is different from root?
also what is meaning of which command

$which cat
$tree -cd

please advise
How to test environmental logicals/variables in Unix/bash script with another Unix/bash script?  

I have below script that creates environmental logicals/variables, - those logicals/variables will be used in some other future scripts as well for efficiency reason. The purpose is to use only logicals/variables and not full directories in future scripts.  What would be another script that would test each of theses logicals/variables? Please provide an example if you can.

export DATADIR1=/root/alldirs/2018/data1
export DATADIR2=/root/alldirs/2018/data2
export DATADIR3=/root/alldirs/2018/data3
echo "This script just stopped running"

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Any suggestions would be appreciated!
Thank you!
I am trying to migrate a Hpunix 10.2 system to a newer system using CentOS 7.

HPunxi is a J6000 two CPUs running a 500 Mhz with 4 gigs of ram 26 drives mirrored 15,000 rpm.
We have 20 users max running one application using XDMCP over the network with 100 mbs Due to j6000 configurations.

CentOS 7:
will be using XRDP instead of XDMCP and so there will be more load on the server for Graphics.

I need some help on this and which GPU to get for the Dell server.

I am attempting to suppress Last Login information being displayed for a specific user when sudo'ing a command.

I have set the attribut "DISPLAY_LAST_LOGIN" to equal 0 for that user in the userdb, however it is still showing the Last Login information.

Our OS is HP UX, realease B.11.31.

root myserver as livehost:/usr/users/myuser/scripts/test $ userdbget -u myuser

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What am I missing?
I have big Unix file aa.0016.s0 which I am unable to open in notepad ++ can make that file small and then open it in notepad

Individual log  files on my server getting zipped every 1 hour and individual log files getting deleted.

PRoblems i am facing with zipped log files are
1. not able to grep them as easily as individual files

2. not able to tail to see any recent issues

if i copy over to local windows laptop using winscp and unzil anf try to open individual file using notepadd++ says too huge file to open.

how to extract zip file in unix box itself and check log files by doing grep and tail etc

please advise
is there way to display disk serial number using lspv in AIX 7.1 ?
Hi Team,

I have the below file .
ID            Name      Hours Worked      Hourly Pay
1425      Juan      18                        14.25
4321      George      22                        21.11
6781      Anne      44                        16.77
1451      Ben            36                        21.77
2277      Tuan      16                        18.77

I need help on the below comamnds on grep, Iam new to grep

I need to display the hourly pay of anne (only the last field )
using grep command.

Secondly , One line comamnd to find the id and hours worked for employees who earn more than $20 per hour.
We have a request from applications team to grant their non-privileged Solaris and AIX ids to be
able to execute their Shell scripts (which contains lines to run binaries) :
  sudo /gl/_ctron_/start1292
  sudo /gl/_ctron_/start1291

Is there any way not to grant them sudo & root and yet still allow them to stop/start the services?
Or if we grant sudo, restrict them to run only those specific scripts & their sudo can't do anything else?

Any way we can use SGID or SUID sticky bits to grant them without giving them root/sudo privileges?
Is there any unix script or shell script  which can fetch all the DB objects from a particular schema along with the proper extension such as (.pks, .pkb etc) to my local system.
Currently writing a management menu interface for managing printers on our HP UX system.

Scripts are written in Korn Shell.

The following command
lpstat -pTERRYTST

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returns the following:-

printer TERRYTST disabled since Apr 10 08:36 -
        new printer
        fence priority : 0

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I need to be able to search the response for keywords to identify states.

So I need to fill a variable with 1 if the printer is disabled, another variable with 1 if its new.

No idea how to complete this in Korn Shell scripting as am very new to the language.

Help! :)
I have a system AIX with 6.1.00 tl9 is necessary install fix for sendmail-cve-2014-3956 ?

The problem exists only if I go to the internet world?

I want to run a .Bat file (using Cygwin) programmatically without user intervention.
Just now it runs through the bash prompt but interactively.

I need to extract a bunch of zip files, but I have requirements.

The zip files are scattered in various folder like this

  • base_folder/
  • base_folder/batch_1/batch_1_1.zip
  • base_folder/batch_1/batch_1_2.zip
  • base_folder/batch_2/batch_2_1.zip
  • base_folder/batch_2/batch_2_2.zip
  • base_folder/batch_2/batch_2_1.zip
  • base_folder/big_batch/batch_a/batch_a_1.zip
  • base_folder/big_batch/batch_a/batch_a_2.zip
  • base_folder/big_batch/batch_b/batch_b.zip

I want to extract the files to another folder and keep the same folder structure

  • base_folder/extracted/
  • base_folder/extracted/batch_1/file_1
  • base_folder/extracted/batch_1/file_2
  • base_folder/extracted/batch_2/file_2_1
  • base_folder/extracted/batch_2/file_2_2
  • base_folder/extracted/batch_2/file_2_1
  • base_folder/extracted/big_batch/batch_a/file_a_1
  • base_folder/extracted/big_batch/batch_a/file_a_2
  • base_folder/extracted/big_batch/batch_b/file_b

I want to extract everything in the zip file except for files that have certain extensions

  • file - OK
  • file.exe - OK
  • file.xml - OK
  • file.txt - Not OK
  • file.xls - Not OK

Is this possible with a few Unix commands? If it isn't entirely possible, what is the closest I can do?
tail -n5000 xyz.log

above shows last 5000 lines right

if i want to see all the 15723 lines of xyz.log what command i have to give

tail -n5000 xyz.log|grep 'ERROR WS'
how to make above case sensitive search like
tail -n5000 xyz.log|grep 'error ws'
how to make above whole word search? so that i wont see below as result ERROR aaa WS etc

please advise
securecrt vs putty

what additional feature or advantages or disadvantages securecrt has compared to putty or mputty.

how much is the licence cost per year or life time?

any advantages using securecrt or any other commercial better tools?

please advise
Need to migrate DNS from old BIND box to Windows DC Server 2016.  Anyone can point to the right direction and steps required?
Also, lots of users are on Ubuntu and Macs.  Would ipconfig /flushdns work on non-windows machines to refresh that after the cutover?
Thanks in advance.

Unix OS





Unix is a multitasking, multi-user computer operating system originally developed in 1969 at Bell Labs. Today, it is a modern OS with many commercial flavors and licensees, including FreeBSD, Hewlett-Packard’s UX, IBM AIX and Apple Mac OS-X. Apart from its command-line interface, most UNIX variations support the standardized X Window System for GUIs, with the exception of the Mac OS, which uses a proprietary system.