.htaccess 301 redirect from old domain to new domain while structure of pages and url are same

I want to redirect http://olddomain.com to http://newdomain.com for my all urls..keeping the page on new domain same. What i mean to say is URLs such as below

http://olddomain.com/home/category/page.html
http://olddomain.com/home/mybook/page2.html
http://olddomain.com/login

should be 301 redirect to the new newdomain but same pages, like below

http://newdomain.com/home/category/page.html
http://newdomain.com/home/mybook/page2.html
http://newdomain.com/login

this is what i have in my .htaccess currently

RewriteEngine on
RewriteCond $1 !^(index\.php|img|public|robots\.txt) [NC]
RewriteRule ^(.*)$ /index.php?/$1 [L]

Please help me to do this cleanly and exlpain things in details since i am new in this.

also does someone know how much time search engines might take to move away from the references of my olddomain? i mean the old-domain urls in search queries should be replaced by new-domain urls... n old domain should go away from search engines.