Use awk to parse and modify every CSV field - parsing

Question

I need to parse and modify a each field from a CSV header line for a dynamic sqlite create table statement. Below is what works from the command line with the appropriate output:
echo ",header1,header2,header3"| awk 'BEGIN {FS=","}; {for(i=2;i<=NF;i++){printf ",%s text ", $i}; printf "\n"}'
,header1 text ,header2 text ,header3 text
Well, it breaks when it is run from within a bash shell script. I got it to work by writing the output to a file like below:
echo $optionalHeaders | awk 'BEGIN {FS=","}; {for(i=2;i<=NF;i++){printf ",%s text ", $i}; printf "\n"}' > optionalHeaders.txt
This sucks! There are a lot of examples that show how to parse/modify specific Nth fields. This issue requires each field to be modified. Is there a more concise and elegant Awk one liner that can store its contents to a variable rather than writing to a file?

Answer 1

sed is usually the right tool for simple substitutions on a single line. Take your pick:
$ echo ",header1,header2,header3" | sed 's/[^,][^,]*/& text/g'
,header1 text,header2 text,header3 text
$ echo ",header1,header2,header3" | sed -r 's/[^,]+/& text/g'
,header1 text,header2 text,header3 text
The last 1 above requires GNU sed to use EREs instead of BREs. You can do the same in awk using gsub() if you prefer:
$ echo ",header1,header2,header3" | awk '{gsub(/[^,]+/,"& text")}1'
,header1 text,header2 text,header3 text

Answer 2

I found the problem and it was me... I forgot to echo the contents of the variable to the Awk command. Brianadams comment was so simple that forced me to re-look at my code and find the problem! Thanks!
I am ok with resolving this but if anyone wants to propose a more concise and elegant Awk one liner - that would be cool.

Answer 3

You can try the following:
#! /bin/bash
header=",header1,header2,header3"
newhead=$(awk 'BEGIN {FS=OFS=","}; {for(i=2;i<=NF;i++) $i=$i" text"}1' <<<"$header")
echo "$newhead"
with output:
,header1 text,header2 text,header3 text

Answer 4

Instead of modifying fields one by one, another option is with a simple substitution:
echo ",header1,header2,header3" | awk '{gsub(/[^,]+/, "& text", $0); print}'
That is, replace a sequence of non-comma characters with text appended.
Another alternative would be replacing the commas, but due to the irregularities of your header line (first comma must be left alone, no comma at the end), that's a bit less easy:
echo ",header1,header2,header3" | awk '{gsub(/,/, " text,", $0); sub(/^ text,/, "", $0); print $0 " text"}'
Btw, the rough equivalent of the two commands in sed:
echo ",header1,header2,header3" | sed -e 's/[^,]\{1,\}/& text/g'
echo ",header1,header2,header3" | sed -e 's/\(.\),/\1 text,/g' -e 's/$/ text/'