awk

webhope · 05-26-2010, 12:52 PM

Hi,
I have this code:

Code:

block='kernel (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=UUID=eab515e9-bc3e-4024-9f01-55fddaa0fb1c  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788'
echo "$block" | awk '/.*UUID=/{ x=gensub(/.*UUID=([-0-9a-fA-F]+)[ )].*/,"\\1",1);  print x}'

I need to return the 1st uuid not the second as it did. Where I have a mistake?
Thanks

grail · 05-26-2010, 08:21 PM

Read the following - http://www.gnu.org/manual/gawk/html_...ring-Functions
Specifically the sections on sub/gsub/gensub

webhope · 05-27-2010, 03:57 AM

Quote:

Originally Posted by grail

Read the following - http://www.gnu.org/manual/gawk/html_...ring-Functions
Specifically the sections on sub/gsub/gensub

I have read about gensub in this manual before I asked this question. I also read about sub and gsub in other awk manual. So where do you want to direct me?

grail · 05-27-2010, 06:52 AM

Well I had already directed you, but it appears it did not work. So I will do the work for you:

Quote:

sub(regexp, replacement [, target])
The sub function alters the value of target. It searches this value, which is treated as a string, for the leftmost, longest substring matched by the regular expression regexp.