Shell Programming and Scripting

Hi,

I have a csv file. I need to add one column at begining of the file, It just contains one value "amr". I am able to add column but unable to put title to it.

Input Data:

Code:

call_id,conn_id,result,ani
1,100,hungup,7601234
2,101,hungup,7601235

Desired Output:

Code:

region,call_id,conn_id,result,ani
amr,1,100,hungup,7601234
amr,2,101,hungup,7601235

Below code gives me output file by adding new column at begining. But it gives "amr" as title, I want title of column as "region". Appreciate your help on this.

Code:

awk '{print "AMR," $0}' <filename>

Code:

awk '{printf (NR>1?"amr,":"region,")} 1'  filename

Thanks for quick reply. It works fine.
Few days back, I raised another question in this forum mainly to add 2 columns after column1. Below is URL of the post.

https://www.unix.com/shell-programmin...#post302478356

Just wondering if i can do both these tasks using single command.

Input Data:

Code:

call_id,conn_id,result,ani
1,100,hungup,7601234
2,101,hungup,7601235

Desired Output:

Code:

region,call_id,key,value,conn_id,result,ani
amr,1,100,dummy,10,hungup,7601234
amr,2,101,dummy,10,hungup,7601235

---------- Post updated at 04:59 PM ---------- Previous update was at 04:57 PM ----------

Correction to desired Output: In summary we want to add three dummy columns. One at beginning of the file, other two after column1.

Code:

region,call_id,key,value,conn_id,result,ani
amr,1,dummy,10,100,hungup,7601234
amr,2,dummy,10,101,hungup,7601235

This should do the trick:

Code:

awk -F, '{$1=NR>1?"amr,"$1",dummy,10":"region,"$1",key,value"} 1'  OFS=, filename

Thanks a lot. it works perfectly as i expected.
Appreciate if you can walk me through the piece of code and give some explanation.

Every awk program consists of a 1 or more blocks of LOGICAL-EXPRESSION { ACTIONS }

If LOGICAL-EXPRESSION is evaluated for each input line and if it equates to true (or it wasn't specified) the ACTIONS block is executed for that line.

(Special LEs of BEGIN (and END) execute their ACTION block once before (or after) the file is processed, this program dosn't use BEGIN or END)

If ACTIONS block is missing the default action is applied, which is print the current line buffer.

In this program we have 1 action block without a LE (so it executes for every line) and after that we have an LE of 1 (true) with no ACTION so it prints every line buffer. We modify the value of field 1 in the 1st action block and this printe in the 2nd.

Breakdown of code as follows:

Thanks a lot for your time. It is really helpful.