bash alias and colorful ls

Everything below should go under ~/.bashrc

alias la='ls -la'
alias gopen='gnome-open'
alias gterminal='gnome-terminal'
alias ls='ls --color'

PS1="\`if [ \$? = 0 ]; then echo \e[33\;40m\\\^\\\_\\\^\e[0m; else echo
\e[36\;40m\\\-\e[0m\\\_\e[36\;40m\\\-\e[0m; fi\` \w> "

NOTE: Make sure alias comes after PS1. PS1 is for cutom prompt.

How to manipulate (copy/move/rename etc..) most recent n files under a directory

In order to list most recent n files under current directory:

ls --sort-time -r | tail -n

n represent number of files, so should be replaced with a number; eg: 5

in order to move, copy, delete or do something with the result, this line can be fed into "cp" "mv" "rm" commands. However the format is important. This line should be in between single quotes. However not the ones near by enter on your keyboard ( ' ), use the ones under esc key ( ` ).
So here is the command line for moving top n files from one directory to another:

mv `ls --sort-time -r | tail -n` /home/yasemin/hebelek/