Sponsored Content
Full Discussion: help on COMM command please
Top Forums UNIX for Dummies Questions & Answers help on COMM command please Post 302435895 by methyl on Thursday 8th of July 2010 01:05:53 PM
Old 07-08-2010
It is important to remember that "comm" assumes that both files are sorted.

Using two sorted test data files file1.txt and file2.txt.
Code:
cat file1.txt 
line 1
line 2
line 3
line 4
line 5

cat file2.txt
line 1
line 3
line 5
line 7

Code:
comm file1.txt file2.txt
                line 1
line 2
                line 3
line 4
                line 5
        line 7

Column 1 contains records only in file1.txt.
Column 2 contains records only in file2.txt
Column 3 contains records common to both files.

Code:
Now: comm -12 removes columns 1 and 2 - leaving only column 3 (lines common to both files).
comm -12 file1.txt file2.txt
line 1
line 3
line 5

Code:
Now: comm -3 removes column 3 - leaving columns 1 and 2 
comm -3 file1.txt file2.txt
line 2
line 4
        line 7

This User Gave Thanks to methyl For This Post:
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Comm, command help

See my other post on sdiff .... I don't think sdiff is able to do what I want. The 'comm' command does what I need and works fine as far as the logic and results. The problem I'm having is with the output format, it outputs 3 columns of data, but because of the way it starts each line... (2 Replies)
Discussion started by: cowpoke
2 Replies

2. UNIX for Advanced & Expert Users

comm command in sorting IP

i have 2 files that contains a sorted list of IP addresses. file_A contains a list of all IPs file_B contains only around 50% of what is in file_A. I tried to execute comm -23 file_A file_B > file_C to get the difference. My objective is to put all the IPs that are in file_A but not... (1 Reply)
Discussion started by: tads98
1 Replies

3. Shell Programming and Scripting

comm command

Hi I have issue with "comm " command file-1 ---- l65059 l65407 l68607 l68810 l69143 l71310 l72918 l73146 l73273 l76411 file-2 ----- (8 Replies)
Discussion started by: amitrajvarma
8 Replies

4. UNIX for Dummies Questions & Answers

help in comm command

Hi all, I need help in comm command , I am having 2 files . I have to display the common line in the two file only onnce and i have to also display the non common line as well. tmpcut1 -- First file cat tmpcut1 smstr_303000_O_432830_... f_c2_queue_sys30.sys30 RUNNING 10 1000... (1 Reply)
Discussion started by: arunkumar_mca
1 Replies

5. Shell Programming and Scripting

HPUX and comm command

I need to compare 2 files. I need to see if 1 file has records that are not in a second file. I did some searching and found the 'comm' command. According to the man pages comm -23 test1.txt test2.txt Will tell me what is in file 1 and not in file 2. So I did a simple test test1.txt has the... (3 Replies)
Discussion started by: guessingo
3 Replies

6. UNIX for Dummies Questions & Answers

Need help with comm command

Hello , I am trying to get contents which are only present in a.csv ,so using comm -23 cat a.csv | sort > a.csv cat b.csv | sort > b.csv comm -23 a.csv b.csv > c.csv. a.csv SKU COUNTRY CURRENCY PRICE_LIST_TYPE LIST_PRICE_EFFECTIVE_DATE TG430ZA ZA USD DF ... (4 Replies)
Discussion started by: RaviTej
4 Replies

7. Linux

comm command help

The manual does not cover this very well. What do the following compares will do ? 1) comm -13 file1 file2: will it display what is in file2 not in file1? 2) comm -23 file1 file2: will it display what in 1 but not in 2 ? Thanks (5 Replies)
Discussion started by: mrn6430
5 Replies

8. Shell Programming and Scripting

Need help regarding formatting(comm -23 command)

Hello all , I have two files a.txt and b.txt which have same content . They contain data that is fetched from database through a java program. When I delete a line in a.txt and run the below command comm -13 a.txt b.txt I am not getting the expected result i.e. the line i deleted from... (5 Replies)
Discussion started by: RaviTej
5 Replies

9. UNIX for Beginners Questions & Answers

How to ignore Case with in COMM command?

Hi, How can i ignore case between 2 files in unix using COMM command. 2 input files are: -bash-4.1$ more x2.txt HELLO hi HI raj -bash-4.1$ more x3.txt hello hi raj COMM command: -bash-4.1$ comm x2.txt x3.txt hello HELLO hi (3 Replies)
Discussion started by: raju2016
3 Replies

10. Shell Programming and Scripting

Highlight 'comm' command output

Given the output below (simplified) extracted from the comparison of two curl -I commands saved in two different files, I am looking for the best approach to highlight the following scenarios in a script: this header exists only in file1.txt but this one does not this one exists in both cases... (1 Reply)
Discussion started by: muppets
1 Replies
comm(1) 							   User Commands							   comm(1)

NAME
comm - select or reject lines common to two files SYNOPSIS
comm [-123] file1 file2 DESCRIPTION
The comm utility reads file1 and file2, which must be ordered in the current collating sequence, and produces three text columns as output: lines only in file1; lines only in file2; and lines in both files. If the input files were ordered according to the collating sequence of the current locale, the lines written will be in the collating sequence of the original lines. If not, the results are unspecified. OPTIONS
The following options are supported: -1 Suppresses the output column of lines unique to file1. -2 Suppresses the output column of lines unique to file2. -3 Suppresses the output column of lines duplicated in file1 and file2. OPERANDS
The following operands are supported: file1 A path name of the first file to be compared. If file1 is -, the standard input is used. file2 A path name of the second file to be compared. If file2 is -, the standard input is used. USAGE
See largefile(5) for the description of the behavior of comm when encountering files greater than or equal to 2 Gbyte ( 2^31 bytes). EXAMPLES
Example 1 Printing a list of utilities specified by files If file1, file2, and file3 each contain a sorted list of utilities, the command example% comm -23 file1 file2 | comm -23 - file3 prints a list of utilities in file1 not specified by either of the other files. The entry: example% comm -12 file1 file2 | comm -12 - file3 prints a list of utilities specified by all three files. And the entry: example% comm -12 file2 file3 | comm -23 -file1 prints a list of utilities specified by both file2 and file3, but not specified in file1. ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of comm: LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES, and NLSPATH. EXIT STATUS
The following exit values are returned: 0 All input files were successfully output as specified. >0 An error occurred. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWesu | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
cmp(1), diff(1), sort(1), uniq(1), attributes(5), environ(5), largefile(5), standards(5) SunOS 5.11 3 Mar 2004 comm(1)
All times are GMT -4. The time now is 11:00 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy