Awk to Count Records with not null

Shell Programming and Scripting
1

Hi,

I have a pipe seperated file
I want to write a code to display count of lines that have 20th field not null.

nawk -F"|" '{if ($20!="") print NR,$20}' xyz..txt

This displays records with 20th field also null.

I would like output as:

2 
nawk -F'|' '$20!="" {tot++} END{print tot}' infile
3 
awk -F"|" '$20 { NN++; next } { N++ } END { print "Null: " N "   Not Null:" NN }' file1
4

Thanks, this works fine.
Sir can you please explain this.

5 
awk -F"|"                                     # Field separator is | 
'
  $20 { NN++; next }                          # if $20 is defined (not null) add 1 to NN (not null) variable, and go to next record
                                              # (after a "next" no rules are evaluated, we go back to the start, for the next record)
  { N++ }                                     # We only get here is record 20 is not defined (is null) so add 1 to N (is null) variable
  END { print "Null: " N "   Not Null:" NN }  # finally, print both counts
' file1