I am a new vi / vim text editor user. How can I quit the vi / vim text editor without saving my changes to a file under Linux / Unix like operating systems?


I have Squid caching proxy server deployed on Rackspace based server in UK. This server has four IP address. I would like to change outgoing IP addresses from default to How do I change proxy server outgoing IP address under Linux or Unix operating systems?


I have MySQL database system running on FreeBSD. The server has multiple ip address. The mysqld used by many websites hosted on two other CentOS based servers. I would like to bind MySQL sever running on Unix / Linux server to more than one IP address such as,, and How can I bind mysqld to multiple ips?


I need to replace special characters with equivalent hexadecimal unicode under Linux or Unix like operating system. How do I list or find out unicodes for given characters?


I am login to a remote server using a ssh client. I am annoyed with the arrow key behavior during insert mode in Vim. As soon as I hit arrow keys, vim display A B C D on screen. How do I fix this problem under Unix like operating systems?


How do I use the rsync tool to copy only the hidden files and directory (such as ~/.ssh/, ~/.foo, and so on) from /home/jobs directory to the /mnt/usb directory under Unix like operating system?


I see many examples and man pages on how to do operations like search-and-replace using sed. But, I want to match a given string or a regular pattern expression and display on the screen. How do I print lines with matching pattern using sed command only under Unix like operating systems?