UNIX for Dummies Questions & Answers

Emp Id    Name
123          aa
123          bb

223          cc
233         dd

334        ee

awk 'BEGIN{A=1} {if($0 ~ /^$/){print A;A++;next}} {A++};'  Input_file
OR
awk '($0 ~ /^$/){print NR}'  Input_file

4
7

var/www$ cat birth.txt
Emp Id Name
123 aa
123 bb

223 cc
233 dd

334 ee

:/var/www$ awk '($0 ~ /^$/){print NR}' birth.txt
:/var/www$ awk 'BEGIN{A=1} {if($0 ~ /^$/){print A;A++;next}} {A++};'  birth.txt
:/var/www$

awk '!NF{print NR}' file

cat -v Input_file