topic Re: comparing 2 files in Operating System - HP-UX

comparing 2 files

Marcia Ferreira — Wed, 03 Dec 2003 12:11:17 GMT

Hi people

I have 2 files: t1 and t2 - both of them has a list of disk devices. I intend to compare both and extract de difference. The problem is diff and comm, compare lines, and I want to compare all the differences.
Does somebody know how can I compare those files?

regards
Marcia Ferreira

Re: comparing 2 files

Jean-Louis Phelix — Wed, 03 Dec 2003 12:14:18 GMT

Hi,

Asumming that files are sorted before, both tools could do it. Else you can give us some line of both files to check format.

Regards.

Re: comparing 2 files

curt larson_1 — Wed, 03 Dec 2003 12:17:21 GMT

have you tried using sdiff?

Re: comparing 2 files

Michael Schulte zur Sur — Wed, 03 Dec 2003 12:21:59 GMT

Hi Marcia,

what do you mean by all the differences? Sort the two file as mentioned before and diff should work. Can you explain a bit more, what differences you mean?

greetings,

Michael

Re: comparing 2 files

Mark Greene_1 — Wed, 03 Dec 2003 12:27:18 GMT

sdiff -s -w [len] file1 file 2 |pg

where [len] is the length of the longest line in either file +1. The -s option tells sdiff to not display lines that are exactly alike. Differeneces in whitepspace (spaces or tabs) are counted as a valid difference.

mark

Re: comparing 2 files

Sathish C — Thu, 04 Dec 2003 02:03:34 GMT

Hi
Considering that the file t1 and t2 has got the device names sorted by unique key ( sort -u ) and you can also use with -c option to see there are no lines with duplicate keys in addition to checking that input file is sorted and the to a diff netween them will suffice your request .

Sathish C

Re: comparing 2 files

Marcia Ferreira — Thu, 04 Dec 2003 07:04:45 GMT

Hi guys

the problem is t1 has 26 lines, and has disks device. t1 has 27 lines and has disk device too. There are some common devices; I want to create a new file e.g t3, that will have only the different disk devices. When I use diff, comm or sdiff, they compare line to line, not line to file.

regards
Marcia

Re: comparing 2 files

Sathish C — Thu, 04 Dec 2003 07:07:01 GMT

hi
that was exactly what almost everyone sujjested to you , sort the file

sort -u t1 > t1.s
sort -u t2 > t2.s
diff t1.s t2.s

should give you the result .

Re: comparing 2 files

Jean-Louis Phelix — Thu, 04 Dec 2003 07:09:44 GMT

Hi,

I'm very sorry, but comm *can* do it if files are sorted first, or you forgot to tell us something about your files. Give us some lines of both or try sort then comm.

Regards.

Re: comparing 2 files

Elmar P. Kolkman — Thu, 04 Dec 2003 07:12:50 GMT

If that is what you want, it can be done like this:

prev=
cat t1 t2 | sort -u | while read line
do
if [ `grep -q "$line" t1 t2 | wc -l` -eq 1 ]
echo $line >> t3
fi
done

Or with awk or perl, using the sorted output of both files. But this is the simplest solution I can think of right now.

Re: comparing 2 files

Elmar P. Kolkman — Thu, 04 Dec 2003 07:15:08 GMT

Problem with diff is that it will give more output then just the lines that are not in both files...

(the prev= line in my solution is nonsense. Was a try that I ignored)

Re: comparing 2 files

Marcia Ferreira — Thu, 04 Dec 2003 07:18:46 GMT

Hi Jean

I did sort -u first. I will send all the files to you understand what I want.
The scene is: I hae to create 2 VGs with sequencial disk devices, but I have others VG created on the server. I have to compare all the disk devices captured by ioscan, and compare with the PVs related to the VGs created. The free disk devices will use to create a new VG. (t1 is the list of a VG had created and t2 is the list of ioscan)

tks

Marcia

Re: comparing 2 files

john korterman — Thu, 04 Dec 2003 07:19:41 GMT

Hi,
if you have two files like this:

# cat file1
fup1
fup2
fup3
fup4
fup5

# cat file2
fup1
fup2
fup4
fup5
fup6

# comm -3 file1 file2
fup3
fup6

Is that not what you want?

regards,
John K.

Re: comparing 2 files

Mark Grant — Thu, 04 Dec 2003 07:22:26 GMT

Well, I am convinced that this is an overly complex way to do it but it is the first thing that came into my head and it does actually work.

#!/usr/bin/perl

open FILE1, "open FILE2, "
while($i=){
chomp($i);
$LIST{$i}++;

}

while($i=){
chomp($i);
$LIST{$i}++
}

foreach $i (keys %LIST){
if($LIST{$i} == 1){
print "$i\n";
}
}

I am sure there are a lot quicker and more sensible ways this can be done

Re: comparing 2 files

Mark Grant — Thu, 04 Dec 2003 07:24:37 GMT

Wow Jon!

I had never even heard of the "comm" command. Looks good to me though :)

Re: comparing 2 files

Marcia Ferreira — Thu, 04 Dec 2003 07:29:25 GMT

Hi John

your sugestion didnÂ´t work. If you see the attachment that I sent, you will understand why.

tks
Marc

Re: comparing 2 files

Elmar P. Kolkman — Thu, 04 Dec 2003 07:31:36 GMT

I think you need to re-create one of the files: one uses the block devices, while the other one uses the raw devices !!!

Or you could use cut to get only the device name and ignore the first 2 parts of the device path:
cut -d/ -f4

Re: comparing 2 files

john korterman — Thu, 04 Dec 2003 07:34:34 GMT

Hi again,
actually, I did not see your attachment before I posted. Therefore I did not understand that the issue was comparing disk devices with raw devices.

regards,
John K.

Re: comparing 2 files

john korterman — Thu, 04 Dec 2003 07:43:59 GMT

Hi again,
how about:
# cat t1| awk -F/ '{print $4} > t1.lim
# cat t2| awk -F/ '{print $4} > t2.lim

The way it was in the detachment caused it to be $4, the idea is to have only the last parts of each line in the files. Then
# comm -3 t1.lim t2.lim
c19t0d0
c19t13d6
c19t13d7
c19t14d0
c19t14d1
c19t14d6
c19t14d7
c19t2d0
c19t3d0
c19t4d0
c19t8d0
c19t8d1
c19t8d2
c19t8d3
c21t12d0
c21t12d1
c21t12d2
c21t12d3
c21t12d4
c21t12d5
c21t12d6
c21t12d7
c21t13d0
c21t13d1
c21t13d2
c21t13d3
c21t13d4

will that do for at starting point?
regards,
John K.

Re: comparing 2 files

Marcia Ferreira — Thu, 04 Dec 2003 07:47:51 GMT

Hi John

sorry, but I sent the wrong file. My partner save another file with the same name.
Your solution was right. The problem finished.

thanks a lot

Marcia