Wednesday, January 18, 2012

Basic Linux Commands



*) How to extract tr.gz. file
To extract one or more members from an archive :
             tar -zxvf {file.tar.gz}

For example, If your tar name is backup.tar.gz, enter the following at a shell prompt:
             tar -zxvf backup.tar.gz



*) How to run .bin file

Change the permission of the file you downloaded to be executable. Type the following command:
              $ chmod +x file.bin

Start the installation process or run .bin file.Type the following command:
             ./file.bin

For example if .bin file name is application.bin. Type:
        $ chmod +x application.bin
        $ ./application.bin



*) How to set a BASH variable equal to the output from a command?

Use $(), which I find easier to read, and allows for nesting.
        OUTPUT=$(ls -1) echo $OUTPUT


*) How to read IP Address In a Shell Script

Type the following command:

ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'


*) How to find out particular ProcessId
                  ps -ef | grep processname
                  eg: ps -ef | grep mysql


*) How to display Line number from a file
          sed -n "linenumber p" file.txt
          sed -n "3 p" file1.txt

*) How to check Hidden file
          ls -a

*) How to check port
         netstat -tulpn


*) How to find directory on linux?
        find / -name 'httpdocs' -type d

the first parameter "/" is where to look, in this case "/" it's the entire system.
-name could be -iname to ignore case also -type is not mandatory
use : man find for more option


*) How to check free RAM size ?
                  free -m


*) How to clear cache memory ? 
        echo 1 > /proc/sys/vm/drop_caches

*) How to check linux version
              cat /proc/version

*) How to check which all service is running ?
                   intictl list 
For a particular service
                   intictl list | grep nova