Shell Programming and Scripting

Hi group,
Can you please tell how to delete specific columns from a file.

I know something like

Code:

awk -F, '{ print $1" "$2" "15 }' input.txt > output.txt

will delete all other columns. But this is in a way to copy some particular columns.

But is there any other way to select just some columns to delete?
Thanks
Mitra

Try this..

Code:

awk -F, '{ $1="" }1' input.txt

Thanks Pamu,
But where should I put the colum number to delete?

Just give like this.. just change the column name...1 and 2

Code:

awk -F, '{ $1="";$2="" }1' input.txt

It would help you (and others) if you could post a sample input and corresponding sample output so that people know what "delete a column" really means to you. This is to clarify whether you need "those 2 consecutive commas" which might crop up when you set a field to a null value.

Hello,
suppose I have something like:

1 1 5 1 1 5 1 1 5
1 1 1 1 1 1 1 1 1
1 4 1 1 4 1 1 4 1
1 1 3 1 1 3 1 1 3
1 5 1 1 5 1 1 5 1
4 1 1 4 1 1 4 1 1
1 1 4 1 1 4 1 1 4
5 3 5 5 3 5 5 3 5
1 1 1 1 1 1 1 1 1

And now if I want to delete only 3, 5, 7 colums then
Now I know something like

Code:

awk -F, '{ print $1" "$2" "$4" "$6" "$8" "$9"}' input.txt > output.txt

will work

Further I can also use cut as :

Code:

cut -f -2,4, 6, 8- input.txt > output.txt

But these all are indirect option for copying rest of the columns.

So again my question is there any direct option to delete some column.

Actually I want to write e script using user given variable for the columns.

Thanks,
Mitra

These are few....

As per user defined might be lit bit difficult to configure with my scripts..
To remove 3 and 5 column.

Code:

first=3
second=5
awk -v FR="$first" -v SE="$second" '{for(i=1;i<=NF;i++)if(i!=FR&&i!=SE)printf$i OFS;print""}' file

awk '{for(i=1;i<=NF;i++)if(i!=3&&i!=5)printf$i OFS;print""}' file

awk '{$3=$5="";gsub(FS "+",FS)}1' file