awk regexp for uuid

webhope · 04-30-2010, 03:49 PM

Where is problem:

Code:

echo $block_new | awk --re-interval '{sub("'$hd'","'$uuid'","g") } $0'

Nothing outputs. It should output the $block_new with hd to uuid replaced.

grail · 04-30-2010, 11:54 PM

Awk sub command:

Code:

sub(regexp, replacement [, target])

All of this - '{sub("'$hd'","'$uuid'","g") } $0' - needs to be in the above format
Assuming you wish to do a global substitution (ie the "g" in your code), you can use:

Code:

gsub(regexp, replacement [, target])

Also, --re-interval is not required here

webhope · 05-01-2010, 01:21 AM

Quote:

Originally Posted by grail

Also, --re-interval is not required here

$hd includes gensub qualifier interval.

Edit:
How should be the regexp?

Code:

/hd\\(0,2\\)/

or

Code:

/hd\(0,2\)/

?

awk: warning: escape sequence `\(' treated as plain `('

Edit
I think that the double escaped backslash should be ok:

Code:

hd=${hd//(/\\\\(}; # left bracket escape
hd=${hd//)/\\\\)}; # right bracket escape

because this

Code:

hd=${hd//(/\\(}; # left bracket escape
hd=${hd//)/\\)}; # right bracket escape

returns awk: warning: escape sequence `\(' treated as plain `('

Edit:
But through ... nothing been replaced :-/

The block output still looks like:

Code:

title Sata Mandriva 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 initrd (hd0,2)/boot/initrd.img

And this was a try to replace (hd0,2) to uuid

grail · 05-01-2010, 04:25 AM

So now you are putting UUID at the front of "/boot/vmlinuz"?

Again I would ask if you have tested that this will actually work, ie is having UUID there plausible, have you tested it?

This worked for me without errors:

Code:

echo "(hd0,2)/boot/vmlinuz" | awk 'gsub(/\(hd0,2\)/,"uuid")'

webhope · 05-01-2010, 06:25 AM

Quote:

Originally Posted by grail

So now you are putting UUID at the front of "/boot/vmlinuz"?

Again I would ask if you have tested that this will actually work, ie is having UUID there plausible, have you tested it?

This worked for me without errors:

Code:

echo "(hd0,2)/boot/vmlinuz" | awk 'gsub(/\(hd0,2\)/,"uuid")'

What is "ie"?
I didn't test. Never mind. Grub boot manager has a editor to change boot item before booting.

Problem is elsewhere. NOT hd(0,2) BUT (hd0,2) - my fault!

catkin · 05-01-2010, 06:30 AM

Quote:

Originally Posted by webhope

What is "ie"?

Strictly i.e., it is short for the Latin expression id est meaning "that is".

webhope · 05-01-2010, 06:33 AM

One more problem in the regex replace. This is the effect: UUID=-4033-55

Code:

++ echo title Sata Mandriva kernel '(hd0,2)/boot/vmlinuz' 
++ awk '{gsub(/\(hd0,2\)/,"UUID="eab515e9-bc3e-4024-9f01-55fddaa0fb1c"") } $0'
+ block_new='title Sata Mandriva kernel UUID=-4033-55/boot/vmlinuz

???

webhope · 05-01-2010, 06:34 AM

Quote:

Originally Posted by catkin

Strictly i.e., it is short for the Latin expression id est meaning "that is".

Quite confusing. Because IE means Internet Explorer

catkin · 05-01-2010, 06:37 AM

Quote:

Originally Posted by webhope

Quite confusing. Because IE means Internet Explorer

And Indo-European and Industrial Engineer(ing)!

EDIT: but none of these was credible in context

grail · 05-01-2010, 07:20 AM

Quote:

"UUID="eab515e9-bc3e-4024-9f01-55fddaa0fb1c""

Quotes around the actual UUID are not required, should be:

Code:

"UUID=eab515e9-bc3e-4024-9f01-55fddaa0fb1c"

Also, sorry about the "ie." thing, it is quite common place in english the same as "eg." to mean for example.

On the other hand not nearly as confusing as the czech in some of your posts

webhope · 05-01-2010, 08:13 AM

OK. Now I try to assign the $block_new back to the content:

Code:

content[$i]=$block_new;
echo $content;

Strange is the output. It looks like the $content was overwriten by $block_new:

Code:

title Sata Mandriva kernel (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2) resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788 initrd (hd0,2)/boot/initrd.img

The content of $content. We should see alll block of menu.lst keeped in memory.

But in real, $block_new should be placed to content[0]

grail · 05-01-2010, 09:03 AM

I think you better have a look at some bash programming sites and how arrays work.

http://tldp.org/LDP/abs/html/arrays.html

webhope · 05-01-2010, 09:16 AM

Well this works fine

Code:

echo ${content[*]};

grail · 05-01-2010, 09:26 AM

Correct

webhope · 05-01-2010, 11:50 AM

I did this:

If uuid is not found in blkid list, then:

Code:

echo "Enter device:"; echo "Pattern: (hd0,0)"; read hd
[[ "$(echo $hd | od -A n -t dC)" -eq 10 ]] && hd="hd(0,0)"

Nice way how to use od