Shell script & csv problem to write in a file

I try to add information in acsv file with a shell script.

For开发者_如何学运维 the moment I add the information, my problem is that the csv file isn't empty at the beginning.

So I would like to put the new information in another column.

But I can't find the way to do this.

here is my code :

sed -i '1i column3' test.csv

sed -i '2i;;4' test.csv

sed -i '3i;;2' test.csv

The output that I have is

column 3

       4

       2

1 2

3 4

And I would like this:

1 2 column 3

3 4 4

 2

Do you think it's possible?

thanks

This should do what you wrote in your example:

sed -i '1s/.*/& column3/' test.csv
sed -i '2s/.*/& 4/' test.csv

with awk (if you want to use space as a separator just leave out the "-vOFS=, -F," part):

awk -vOFS=, -F, 'NR==1 {$3="col3"; print;}' test.csv
awk -vOFS=, -F, 'NR==2 {$3=4; print;}' test.csv

Change the first column:

awk -vOFS=, -F, 'NR==1 {$1="col1"; print;}' test.csv

Insert a column between the 2:

awk -vOFS=, -F, 'NR==1 {print $1,"newcol",$2;}' test.csv