Title: Help with some bash script
Post by: Manu Zacharia (-M-) on January 30, 2008, 12:02:22 PM

Hi,

I need some help with bash scripting.

I have two files and the contents are as follows:

File1

Code:

1111
2222
4444
5555
4444
6666

File 2

Code:

9999
0000
4444
5555
7777
8888

I am looking for a script that will compare the two files or two list and output the common line that is available on both the files. In the above example, the output should be

Code:

4444
5555

Can anybody help me with this?

Title: Re: Help with some bash script
Post by: dean on January 30, 2008, 12:16:21 PM

why use a script? The commands for this exist already.

shell> comm -1 -2 file1.txt file2.txt

This will display lines that are the same in both.

dean

Title: Re: Help with some bash script
Post by: Manu Zacharia (-M-) on January 30, 2008, 12:24:27 PM

Thank you so much Dean.

Title: Re: Help with some bash script
Post by: dean on January 30, 2008, 12:37:02 PM

No problem,

Also look into using AWK for tasks such as these.

dean

Title: Re: Help with some bash script
Post by: Manu Zacharia (-M-) on January 30, 2008, 11:55:25 PM

Hi

The comm does a line by line compare. I am looking for a compare where each line (entry) from file 1 is compared with all the lines on the second file and whatever value is common on both files is displayed.

For example, file1 contains

Code:

3322
1212
1111
2222
4444
5555
4545
6666

and file 2 contains

Code:

9999
0000
4444
5555
7777
8888

The output should be

Code:

4444
5555

I found the following script after googling,

Code:

comm file1.txt file2.txt | awk -F'\t' '
{a[NF,++i[NF]]=$NF}
END{
print "Common\tFile1\tFile2"
for(j=1;j<=i[1]||j<=i[2]||j<=i[3];++j)
print a[3,j]"\t"a[1,j]"\t"a[2,j]
print "===\t===\t==="
print i[3]"\t"i[1]"\t"i[2]
}'

but the above script is giving the wrong output, not working for me. The output is as follows:

Code:

user@sysadmn ~
$ ./compare.sh
Common File1 File2
3322 9999
1212 0000
1111 4444
2222 5555
4444 7777
5555 8888
4545
6666
=== ==== ====
8 6

user@sysadmn ~

The desired output is:

Code:

user@sysadmn ~
$ ./compare.sh
Common File1 File2
4444 3322 9999
5555 1212 0000
1111 4444
2222 5555
4444 7777
5555 8888
4545
6666
=== === ===
8 6

user@sysadmn ~

Thanks in advance

Title: Re: Help with some bash script
Post by: zr0crsh on January 31, 2008, 12:09:15 PM

Here is the quick and dirty that might work for you:

Code:

cat file1 |while read line; do grep ${line} file2 ; done

EH-Net

Ethical Hacking Discussions and Related Certifications => Programming => Topic started by: Manu Zacharia (-M-) on January 30, 2008, 12:02:22 PM