awk metacharacters 1

[goldenradium2001]

What is the difference between the *, +, and ? metacharacters in awk? I seem to receive the same output from all of these commands.

Any help will be appreciated!

Thanks!

 

[CaKiwi]

* is zero or more of the previous character (or regexp)
+ is one or more of the previous character (or regexp)
? is zero or one of the previous character (or regexp)
CaKiwi

 

[goldenradium2001]

So, * and ? are not any different? What exactly does + do? I've seen those definitions on the Internet and every book I have but not really an example.

Here's my file:

Jean
Jeff
John
Josh
Jo

if I were to use J+, it would show all names. If I were to use J?, all names are displayed. And if I used J*, all names are displayed. Why have three different metacharacters if they do the same thing?

Any help? THanks!

 

[CaKiwi]

Answered in the awk forum thread271-346586 CaKiwi