Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

comparing two files

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting comparing two files
# 1  
Old 02-04-2009
comparing two files
I have two files

f1:
xxxxxx 12
ccccc 36

f2:
xxxxxx 63
ccccc 11

first think what i have to do is check if first column are and if yes check if second column in is bigger in f2 then in f1
# 2  
Old 02-04-2009
Code:
awk 'NR==FNR{a[$1]=$2;next}a[$1] && $2>a[$1]' f1 f2

Regards
# 3  
Old 02-04-2009
Quote:
Originally Posted by Franklin52
Code:
awk 'NR==FNR{a[$1]=$2;next}a[$1] && $2>a[$1]' f1 f2

Regards
Franklin,

Could you please explain me this.
# 4  
Old 02-04-2009
[quote=tommy1;302284028]Franklin,

Could you please explain me this.

Thanks,
Last edited by tommy1; 02-04-2009 at 03:19 PM..
# 5  
Old 02-05-2009
[quote=tommy1;302284029]
Quote:
Originally Posted by tommy1
Franklin,

Could you please explain me this.

Thanks,
Sure, here we go:

Code:
awk 'NR==FNR{a[$1]=$2;next}a[$1] && $2>a[$1]' f1 f2

NR==FNR -> If the first file is read:

{a[$1]=$2;next} -> Define an array a with the value of field 1 as index, assign the value of field 2 to it and read the next line of the first file

Actions for the second file:

a[$1] && $2>a[$1] -> Print the line if the array was defined previously and the 2nd field is greater then the value of the array


Regards
# 6  
Old 02-05-2009
[quote=Franklin52;302284276]
Quote:
Originally Posted by tommy1
Sure, here we go:

Code:
awk 'NR==FNR{a[$1]=$2;next}a[$1] && $2>a[$1]' f1 f2

NR==FNR -> If the first file is read:

{a[$1]=$2;next} -> Define an array a with the value of field 1 as index, assign the value of field 2 to it and read the next line of the first file

Actions for the second file:

a[$1] && $2>a[$1] -> Print the line if the array was defined previously and the 2nd field is greater then the value of the array


Regards
Awesome ! Thank you Franklin!!

I have one more quick question.. how does awk know that we are referring to the second file at "a[$1] && $2>a[$1]", how do we specify if we have more than 2 files?

Regards
# 7  
Old 02-05-2009
[quote=tommy1;302284499]
Quote:
Originally Posted by Franklin52

Awesome ! Thank you Franklin!!

I have one more quick question.. how does awk know that we are referring to the second file at "a[$1] && $2>a[$1]", how do we specify if we have more than 2 files?

Regards
The next statement in this block prevents the program to reach the next line if we read the 1st file:

Code:
{a[$1]=$2;next}

If you have more files you can use the FILENAME variable:

Code:
FILENAME=="file1"{commands ...}
FILENAME=="file2"{commands ...}

Regards
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Comparing two files and list the difference with common first line content of both files

I have two file as given below which shows the ACL permissions of each file. I need to compare the source file with target file and list down the difference as specified below in required output. Can someone help me on this ? Source File ************* # file: /local/test_1 # owner: own #... (4 Replies)
Discussion started by: sarathy_a35
4 Replies

2. Shell Programming and Scripting

Comparing files in a directory against an array of files

I hope I can explain this correctly. I am using Bash-4.2 for my shell. I have a group of file names held in an array. I want to compare the names in this array against the names of files currently present in a directory. If the file does not exist in the directory, that is not a problem.... (5 Replies)
Discussion started by: BudMan
5 Replies

3. Shell Programming and Scripting

Comparing the files

Hi Friends, I have file1.txt file2.txt I tried using the diff and comm but not getting the expected output.. I want where exactly the miss match occurs. probably the field. Sourcevalue|Targetvalue|Linenumber|field 29123975|2923975|3|1 Please help. (6 Replies)
Discussion started by: i150371485
6 Replies

4. Shell Programming and Scripting

Help with comparing two files

Hi all I have to compare two file this time one is P11223 x1124 x1145 t5678 e3456 z2345 another file P11223 x s (2 Replies)
Discussion started by: manigrover
2 Replies

5. UNIX for Advanced & Expert Users

How to find duplicates contents in a files by comparing other files?

Hi Guys , we have one directory ...in that directory all files will be set on each day.. files must have header ,contents ,footer.. i wants to compare the header,contents,footer ..if its same means display an error message as 'files contents same' (7 Replies)
Discussion started by: Venkatesh1
7 Replies

6. Shell Programming and Scripting

Comparing the matches in two files using awk when both files have their own field separators

I've two files with data like below: file1.txt: AAA,Apples,123 BBB,Bananas,124 CCC,Carrot,125 file2.txt: Store1|AAA|123|11 Store2|BBB|124|23 Store3|CCC|125|57 Store4|DDD|126|38 So,the field separator in file1.txt is a comma and in file2.txt,it is | Now,the output should be... (2 Replies)
Discussion started by: asyed
2 Replies

7. Shell Programming and Scripting

Need help comparing two files and deleting some things in those files!

So I have two files: File1 pictures.txt 1.1 1.3 dance.txt 1.2 1.4 treehouse.txt 1.3 1.5 File2 pictures.txt 1.5 ref2313 1.4 ref2345 1.3 ref5432 1.2 ref4244 dance.txt 1.6 ref2342 1.5 ref2352 1.4 ref0695 1.3 ref5738 1.2 ref4948 1.1 treehouse.txt 1.6 ref8573 1.5 ref3284 1.4 ref5838... (24 Replies)
Discussion started by: linuxkid
24 Replies

8. Shell Programming and Scripting

Need Help Comparing two Files

I really need help on creating a script that does the following: I have one file (File 1) with lines in the following format: Name.maf score1 score2 I have a second file (File 2) with lines in the following format: label start end Name What I need to do is compare File 1 and... (1 Reply)
Discussion started by: awknerd
1 Replies

9. Shell Programming and Scripting

Comparing files

I have a file called X, which contains the following: 10 100 200 300 I then have file Y, which containts the following: 10 200 500 800 I want to write a script that will compare the contents of Y with the contents of X and ONLY return values in Y that does not exist in X (output... (5 Replies)
Discussion started by: soliberus
5 Replies

10. UNIX for Advanced & Expert Users

comparing shadow files with real files

Hi I need to compare shadow file sizes with their real file counterparts. If the shadow file size differs form the realfile size then it must send a mail. My problem is that our system has over 1600 shadowfiles in different directories, with different names. the only consistancy is the .sh file... (4 Replies)
Discussion started by: terrym
4 Replies
Login or Register to Ask a Question