Unix commands

1.Delete a file:
rm filename

2.Delete a directory and its contents
rm -rf directoryName/

3.To give permission to execute:
sudo chmod 755 jdk-6u21-linux-i586.bin

4.Copy to remote system
scp -r /home/rocky/ROOT15Sep.war user@192.168.0.60:/home/user/

4.To change user password:
passwd rocky
[enter new paasword]

5.Find and kill jboss process
ps -ef | grep jboss
sudo kill -9 6789

6.Rename system name
http://www.makeuseof.com/tag/change-computer-ubuntu-1010/

7. text search in files under a folder
find myDir -type f -name *.txt -exec grep "hello" {} /dev/null \;

Note: Here search text is "hello", folder is "myDir", file name is in the format "*.txt"