[R] Regular Expressions

[Sangick Jeon]

Hi,

Is there a way to use regular expressions to capture two or more words in a 
sentence?  For example, I wish to to find all the lines that have the words "thomas", 
"perl", and "program", such as "thomas uses a program called perl", or "perl is a 
program that thomas uses", etc.

I'm sure this is a very easy task, I would greatly appreciate any help.  Thanks!

Sangick