Adnan Khurshid on January 31st, 2015

Enthusiastic about python? Well, this language has been gaining popularity. Only 2 commands & you will be set to go. $ yum groupinstall “Development tools” $ yum install zlib–devel bzip2–devel openssl–devel ncurses–devel sqlite–devel readline–devel tk–devel gdbm–devel db4–devel libpcap–devel xz–devel It will take around 3 to 5 minutes & you will be set. Run “Python” to […]

Continue reading about How to install Python on CentOS

Adnan Khurshid on December 15th, 2014

Having difficulty in connecting to internet from VMware? Recently I installed CentOS in the VMWARE for configuration purposes. I thought it would be beneficial to share how to connect to internet via Linux installed on VMWARE; it can save your time Please note that network can be configured on Linux from the below files. /etc/sysconfig/network […]

Continue reading about How to access internet from VMWARE (Linux)

Adnan Khurshid on June 6th, 2011

touch command is used to modify the timestamps of the file. Suppose, you want to modify the time stamp of the file top.txt, use the command as follows: linux:~ # ls -l top.txt -rw-r–r–  1 root root 9637 Apr  2 00:20 top.txt linux:~ # linux:~ # touch -t 201106062145 top.txt linux:~ # ls -l top.txt […]

Continue reading about How to modify the timestamp of files in Linux

Adnan Khurshid on May 30th, 2011

The background processes in Linux refer to the processes running in the background for a particular session which foreground processes are the ones which are currently being operated upon. The commands to manage the processes are as follows: Show background jobs: Use ‘bg’ command to display all the processes which are running in the background.

Continue reading about Understanding background and foreground jobs in Linux

Adnan Khurshid on April 5th, 2011

A crontab contains entries for a cron job. Entries in the crontab are separated by newline characters. Each crontab contains six fields separated by spaces as shown below: Minute Hour Day Month Weekday Command Each field is explained below: Minute: 0 ~ 59 Hour: 0 ~ 23 Day: 1 ~ 31 Month: 1 ~ 12 […]

Continue reading about All you need to know about Crontab

Adnan Khurshid on April 4th, 2011

For large output which is not able to fit in a single window, scrolling the results can skip data while it looks messy as well. to get rid of scrolling, you can use the command “set pause on”. With pause ON, the output will come in small chunks and will continue only when you press […]

Continue reading about How to get rid of scrolling for long SQL output in Oracle

Adnan Khurshid on April 4th, 2011

This post will guide you how you can play with SQL using the interactive variable values inside the statement. To begin with, suppose we even don’t know which table we want to query from. To check all the tables inside the logged in database, you can query the TABLE_NAME from user_tables. To get all the […]

Continue reading about How to run SQL commands with an input variable

Adnan Khurshid on April 4th, 2011

While typing commands on a unix system, removing a miss-typed character by the backspace writes down a character ^H instead. To remove a character, you must use Ctrl+BackSpace instead. However, this exercise is quite frustrating for the users. To get rid of this, use stty erase command as demonstrated below: root@mms1 # ls -l^H^H^H^H ls: […]

Continue reading about How to remove the backspace ^H character from Unix session

This is one of the most commonly observed error in Oracle database. The exact error description is as follows: ERROR: ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist SUN OS Error: 2: No such file or directory Due to this error, the DBA is unable to login to the SQL prompt. This […]

Continue reading about How to resolve Oracle Error “shared memory realm does not exist”

Adnan Khurshid on March 24th, 2011

I had written an article previously on how to set the environment variables in Linux/Unix system. You may want to have a look it here. Let’s see how we can delete the variables in the SUN Solaris system. The “env” command will display all the variables in the current user. SUNOS% env HOME=/opt/oracle PATH=/opt/JDK/j2sdk1.4.1_02/bin:/bin:/usr/bin:/usr/ucb:/usr/ccs/bin:/etc:/usr/local/bin:/opt/usr/local/bin:/usr/dt/bin:/opt/iplanet/servers:/opt/oracle/oracle9/bin:/opt/oracle/jre/1.1.8/bin:/opt/oracle/web/bin:/opt/oracle/mms_run/bin:/opt/oracle/mms_run/shell:. LOGNAME=oracle […]

Continue reading about How to delete environment variables in SUN Solaris