I am not able to understand the complete functioning of period (.) operator in Regular Expression under unix terminal..
It says it matches any single character.. When i gave grep 'c.t' a.txt, it return results such as cat, cbt, cmt etc.. Should it pring any other type of data too??? as i am not clear with the basics of this period operator.
What if i give grep 'c[abm].t' a.txt, it is not giving the expected results i.e. I thought it should print only cat or cbt or cmt but it prints only caat, which was one of the data. Please clarify.
Also if there is any tutorial, wherein I can master the skills of Regular Expression, then please share.. Thanks a lot.. Please try and solve my query..