awk file sanity check. awk check for null/missing values in csv files

Question

I'm trying to write a simple file sanity check script. I have a directory with dozen CSV files containing id,edname,firstname,lastname,suffix,email.

I like to write a awk script to check if first field contain a number and is not empty. and fields number 3,4 & 6 are not empty and that the file contains 6 fields no more no less than 6, if all of this conditions are true nothing happens but if any of these conditions failed, re-name the file to .bad. here is wha i have but is not picking up missing values in columns 4,6.

for f in *.csv; do 
  awk -F, '!(NF==6 && $1+0==$1 && $3$4$6!=""){f=1; exit} END{exit f}' "$f" || mv "$f" "$f".bad;
done

Answer 1

As steeldriver pointed out in the comments, your third test will be true if any of the three fields isn't empty. I assume you actually want something like this:

for f in *.csv; do 
  awk -F, '!(NF==6 && $1+0==$1 && $3!="" && $4!="" && $6!=""){f=1; exit} 
            END{exit f}' "$f" || mv "$f" "$f".bad;
done

Answer 2

No need to do string comparisons if you just want to ensure it's not null. Empty strings are falsy, so:

awk -F, 'BEGIN {flag=0} !(NF==6 && $1+0==$1 && $3 && $4 && $6) {flag=1} END {exit flag}'