Grep and substitute? - ksh

Question

I have to parse ASCII files, output the relevant data to a comma-delimited file and load it into a database table.
The specs for the file format have been recently updated and one section is causing problems. This is the original layout for that section.
CSVHeaderAttr:PUIS,IdleImmediate,POH,Temp,WorstTemp
CSVValuesAttr:NO,NO,9814,31,56
I parse it with grep thusly
CSVAttributes=$(grep ^CSVValuesAttr: ${filename}|cut -d':' -f2)
[ -z "$CSVAttributes" ] && CSVAttributes="NA"
It works great but now that the section has new fields and they are named differently
CSVHeaderAttr:PUIS,IdleImmediateSupported,IdleImmediateEnabled,POH,Temp,WorstTemp
CSVValuesAttr:NO,YES,YES,23861,31,51
Right now, I am grepping the files based on their layout (there is a field in the the header which tells me the version of the layout) to two different comma-delimited files and load them into two different tables. I would like to output both sections to the same file so the data scientist only has one table to use in his analysis.
Is there a way to use grep to produce an output like this and substitute empty fields with NA?
For one file type:
CSVHeaderAttr:PUIS,IdleImmediate,IdleImmediateSupported,IdleImmediateEnabled,POH,Temp,WorstTemp
CSVValuesAttr:NO,NO,NA,NA,9814,31,56
For the other file type:
CSVHeaderAttr:PUIS,IdleImmediate,IdleImmediateSupported,IdleImmediateEnabled,POH,Temp,WorstTemp
CSVValuesAttr:NO,NA,YES,YES,23861,31,51
Thanks for your input.

Answer 1

sed -n '/CSVHeaderAttr:/ c\
CSVHeaderAttr:PUIS,IdleImmediate,IdleImmediateSupported,IdleImmediateEnabled,POH,Temp,WorstTemp
/CSVValuesAttr:/ {
/\([^,]*,\)\{5\}/ s/\([^,]*,\)/&NA,/
t p
s/\(\([^,]*,\)\{2\}\)/\1NA,NA,/
# t p
: p
p
}' AllYourFiles > ConcatFile
using sed that test how many column (with /\([^,]*,\)\{5\}/) before changing the new layout