How to redirect duplicate lines from a file????

Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers How to redirect duplicate lines from a file????
# 1  
How to redirect duplicate lines from a file????


I am having a file which contains many duplicate lines. I wanted to redirect these duplicate lines into another file.

Suppose I have a file called file_dup.txt which contains some line as



If you see the above file contents the 3 and 4 numbered lines are duplicated. I want to redirect the lines which are duplicated in to another file say file_nodup.txt. So the file_nodup.txt will contain the line as follows



Is there any command in UNIX which will give me the above work done?
Or any AWK way to solve it.

Thanks in advance…

# 2  
awk ' ++arr[$0] > 1 ' file_dup.txt > file_nodup.txt

# 3  
I think it can work by this way also:
sort file1 |uniq -d > file2
this will extract the duplicated lines and redirects them to file2

you can also specify the number of duplication of every line at the begining of the line:
sort file1 |uniq -c > file2
# 4  
Hey thanks for all of you who suggested very good options to solve my problem.

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #641
Difficulty: Medium
NeXTSTEP had a Unix operating system based on the Minix kernel, plus source code from System V.
True or False?

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Duplicate lines in a file

I have a file with following data A B C I would like to print like this n times(For eg:5 times) A B C A B C A B C A B C A (7 Replies)
Discussion started by: nsuresh316
7 Replies

2. Shell Programming and Scripting

bash keep only duplicate lines in file

hello all in my bash script I have a file and I only want to keep the lines that appear twice in the file.Is there a way to do this? thanks in advance! (4 Replies)
Discussion started by: vlm
4 Replies

3. UNIX for Advanced & Expert Users

In a huge file, Delete duplicate lines leaving unique lines

Hi All, I have a very huge file (4GB) which has duplicate lines. I want to delete duplicate lines leaving unique lines. Sort, uniq, awk '!x++' are not working as its running out of buffer space. I dont know if this works : I want to read each line of the File in a For Loop, and want to... (16 Replies)
Discussion started by: krishnix
16 Replies

4. Shell Programming and Scripting

Redirect lines to another file

Hi, I have a file with a size of 10 mb and I need to redirect some specific lines to a new files. For eg. Executed Restore for 11227.EDCS.551.01.201110 from /tmp/bk/restore/CR81500/content/S24U15VA2.2010-10-29.16:49.EDT/ Operation output: <U+FEFF>Oct... (4 Replies)
Discussion started by: gsiva
4 Replies

5. Shell Programming and Scripting

Duplicate lines in a file

Hi All, I am trying to remove the duplicate entries in a file and print them just once. For example, if my input file has: 00:44,37,67,56,15,12 00:44,34,67,56,15,12 00:44,58,67,56,15,12 00:44,35,67,56,15,12 00:59,37,67,56,15,12 00:59,34,67,56,15,12 00:59,35,67,56,15,12... (7 Replies)
Discussion started by: faiz1985
7 Replies

6. AIX

Grep multiple lines and redirect to file

I have setof files with data and with same fields multiple times in each of the files. for example: file 1 name = mary kate last name = kate address = 123 street = abc name = mary mark last name = mark address = 456 street = bcd file 2 name = mary kate last name = kate... (2 Replies)
Discussion started by: relearner
2 Replies

7. Shell Programming and Scripting

removing the duplicate lines in a file

Hi, I need to concatenate three files in to one destination file.In this if some duplicate data occurs it should be deleted. eg: file1: ----- data1 value1 data2 value2 data3 value3 file2: ----- data1 value1 data4 value4 data5 value5 file3: ----- data1 value1 data4 value4 (3 Replies)
Discussion started by: Sharmila_P
3 Replies

8. UNIX for Dummies Questions & Answers

Remove Duplicate lines from File

I have a log file "logreport" that contains several lines as seen below: 04:20:00 /usr/lib/snmp/snmpdx: Agent snmpd appeared dead but responded to ping 06:38:08 /usr/lib/snmp/snmpdx: Agent snmpd appeared dead but responded to ping 07:11:05 /usr/lib/snmp/snmpdx: Agent snmpd appeared dead but... (18 Replies)
Discussion started by: Nysif Steve
18 Replies

9. UNIX for Advanced & Expert Users

Duplicate lines in the file

Hi, I have a file with duplicate lines in it. I want to keep only the duplicate lines and delete the non duplicates. Can some one please help me? Regards Narayana Gupta (3 Replies)
Discussion started by: guptan
3 Replies

10. Shell Programming and Scripting

Remove Duplicate Lines in File

I am doing KSH script to remove duplicate lines in a file. Let say the file has format below. FileA 1253-6856 3101-4011 1827-1356 1822-1157 1822-1157 1000-1410 1000-1410 1822-1231 1822-1231 3101-4011 1822-1157 1822-1231 and I want to simply it with no duplicate line as file... (5 Replies)
Discussion started by: Teh Tiack Ein
5 Replies

Featured Tech Videos