How to remove mth and nth column from a file?

Login or Register to Ask a Question and Join Our Community

How to remove mth and nth column from a file?

Tags

Login to Discuss or Reply to this Discussion in Our Community

Top Forums Shell Programming and Scripting How to remove mth and nth column from a file?

08-06-2013

Registered User

12, 0

Join Date: Jan 2013

Last Activity: 11 July 2014, 2:02 AM EDT

Posts: 12

Thanks Given: 8

Thanked 0 Times in 0 Posts

How to remove mth and nth column from a file?

Hi,

i need to remove mth and nth column from a csv file. here m and n is not a specific number. it is a variable

ex.

m=2
n=5

now i need to remove the 2nd and 5th line.. Please help how to do that.

Thanks!!!

zaq1xsw2

View Public Profile for zaq1xsw2

Find all posts by zaq1xsw2

08-06-2013

Registered User

1,040, 213

Join Date: Dec 2010

Last Activity: 20 September 2014, 2:08 AM EDT

Posts: 1,040

Thanks Given: 62

Thanked 213 Times in 203 Posts

Code:

awk '{$a="";$b=""} 1' a=$m b=$n

These 2 Users Gave Thanks to Jotne For This Post:

Jotne

View Public Profile for Jotne

Find all posts by Jotne

08-06-2013

Registered User

3,231, 978

Join Date: Dec 2009

Last Activity: 11 June 2014, 8:40 PM EDT

Posts: 3,231

Thanks Given: 179

Thanked 978 Times in 791 Posts

Quote:

Originally Posted by zaq1xsw2

i need to remove mth and nth column

Quote:

Originally Posted by Jotne

Code:

awk '{$a="";$b=""} 1' a=$m b=$n

Assigning an empty string does not remove a column. The number of fields in the record will remain unchanged.

Regards,
Alister

alister

View Public Profile for alister

Find all posts by alister

08-06-2013

Moderator

3,105, 1,603

Join Date: May 2013

Last Activity: 31 August 2020, 1:46 AM EDT

Location: Chennai

Posts: 3,105

Thanks Given: 1,269

Thanked 1,603 Times in 1,369 Posts

Thanks a lot Jotne
But I guess we should give file name too after the command as follows. Where we have file named df_test_removing_column in which we want to remove
3rd and 4th column.

Code:

$ m=3
$ n=4
$ awk '{$a="";$b=""} 1' a=$m b=$n df_test_removing_column

Output should be as follows. It is just an exmaple for df (Disk space of AIX server.)

Code:

Filesystem 512-blocks   Iused %Iused Mounted on
/dev/hd4 262144   5812 9% /
/dev/hd2 9175040   79431 7% /usr
/dev/hd9var 3014656   3968 2% /var
/dev/hd3 2097152   113 1% /tmp
/proc -   - - /proc
/dev/hd10opt 1048576   1741 2% /opt
/dev/lv_home 720896   853 1% /home
/dev/lv_hd 524288   55 1% /opt/hd

Thanks,
R. Singh

RavinderSingh13

View Public Profile for RavinderSingh13

Find all posts by RavinderSingh13

08-06-2013

Registered User

1,040, 213

Join Date: Dec 2010

Last Activity: 20 September 2014, 2:08 AM EDT

Posts: 1,040

Thanks Given: 62

Thanked 213 Times in 203 Posts

aliester is correct.
This can be cleaned by

Code:

awk '{$a=$b="";gsub(FS "+",FS)} 1' a=$m b=$n df_test_removing_column

This User Gave Thanks to Jotne For This Post:

Jotne

View Public Profile for Jotne

Find all posts by Jotne

08-06-2013

Registered User

12, 0

Join Date: Jan 2013

Last Activity: 11 July 2014, 2:02 AM EDT

Posts: 12

Thanks Given: 8

Thanked 0 Times in 0 Posts

Quote:

Originally Posted by Jotne

Code:

awk '{$a="";$b=""} 1' a=$m b=$n

That is nice and quick.. Thanks.. i am using the below command on my csv file

Code:

awk -F "," 'OFS="," {$a="";$b=""} 1' a=$m b=$n output.csv

the output is like below...

Code:

AED03852181,AED03852181,AED03852181,04/08/2013,04/08/2013,1239,,3,3,3,3,,3
AED09020382,AED09020382,AED09020382,04/08/2013,04/08/2013,1239,,3,3,3,3,,3

you can see that 7th and 12th column is set to BLANK as m=7 and n=12. can you modify the above command to remove the blank column. Actually i dont want to replace ",," with a ",". then it will create problem where actually there is blank field in the original file ..

Last edited by Franklin52; 08-06-2013 at 05:16 AM.. Reason: Please use code tags

zaq1xsw2

View Public Profile for zaq1xsw2

Find all posts by zaq1xsw2

08-06-2013

Registered User

1,040, 213

Join Date: Dec 2010

Last Activity: 20 September 2014, 2:08 AM EDT

Posts: 1,040

Thanks Given: 62

Thanked 213 Times in 203 Posts

This should do it

Code:

awk -F, '{$a=$b="";gsub(FS "+",FS)} 1' a=$m b=$n OFS=, df_test_removing_column

This User Gave Thanks to Jotne For This Post:

Jotne

View Public Profile for Jotne

Find all posts by Jotne

Login or Register to Ask a Question

Previous Thread | Next Thread

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Taking nth column and putting its value in n+1 column using awk

Hello Members, Need your expert opinion how to tackle below. I have an input file that looks like below: USS|AWCC|AFGAW|93|70 USSAA|Roshan TDCA|AFGTD|93|72,79 ALB|Vodafone|ALBVF|355|69 ALGEE|Wataniya (Nedjma)|DZAWT|213|50,550 I like output file in below format: ...

2. Shell Programming and Scripting

How to search and replace string from nth column from a file?

I wanted to search for a string and replace it with other string from nth column of a file which is comma seperated which I am able to do with below # For Comma seperated file without quotes awk 'BEGIN{OFS=FS=","}$"'"$ColumnNo"'"=="'"$PPK"'"{$"'"$ColumnNo"'"="'"$NPK"'"}{print}' ${FileName} ...

3. Shell Programming and Scripting

Remove the values from a certain column without deleting the Column name in a .CSV file

4. Shell Programming and Scripting

Break Column nth in a CSV file into two

Hi Guys, Need help with logic to break Column nth in a CSV file into two for e.g Refer below the second column as the nth column "abcd","","type/beta-version" need output in a following format "abcd","/place/asia/india/mumbai","/product/sw/tomcat","type/beta-version" ...

5. Shell Programming and Scripting

Need help with awk statement to break nth column in csv file into 3 separate columns

Hello Members, I have a csv file in the format below. Need help with awk statement to break nth column into 3 separate columns and export the changes to new file. input file --> file.csv cat file.csv|less "product/fruit/mango","location/asia/india","type/alphonso" need output in...

6. Shell Programming and Scripting

Get the nth word of mth line in a file

Hi.. May be a simple question but I just began to write unix scripts a week ago, for sorting some huge amount of experiment data, so I got no common sense about unix scripting and really need your helps... The situation is, I want to read the nth word of mth line in a file, and then store it...

7. Shell Programming and Scripting

Calculating average for every Nth line in the Nth column

Is there an awk script that can easily perform the following operation? I have a data file that is in the format of 1944-12,5.6 1945-01,9.8 1945-02,6.7 1945-03,9.3 1945-04,5.9 1945-05,0.7 1945-06,0.0 1945-07,0.0 1945-08,0.0 1945-09,0.0 1945-10,0.2 1945-11,10.5 1945-12,22.3...

8. Shell Programming and Scripting

Using AWK to find top Nth values in Nth column

I have an awk script to find the maximum value of the 2nd column of a 2 column datafile, but I need to find the top 5 maximum values of the 2nd column. Here is the script that works for the maximum value. awk 'BEGIN { subjectmax=$1 ; max=0} $2 >= max {subjectmax=$1 ; max=$2} END {print...

9. Shell Programming and Scripting

How to Print from nth field to mth fields using awk

Hi, Is there any short method to print from a particular field till another filed using awk? Example File: File1 ==== 1|2|acv|vbc|......|100|342 2|3|afg|nhj|.......|100|346 Expected output: File2 ==== acv|vbc|.....|100 afg|nhj|.....|100

Login or Register to Ask a Question