help

I want to check the data format ,if date is invalid ,replace with null.

xxxx      2001-01-01
yyyy      200-09-09
zzz      2000-009-08

xxxx      2001-01-01
yyyy      null
zzz        null

Thanks inadvance
Akil

one way:

#  nawk '$2!~"[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]"{$2="null"}{print}' infile
xxxx      2001-01-01
yyyy null
zzz null

Hi
Thanks,its working fine

Thanks,
Akil