Validate date format in a shell script

Question

I have to create a Shell Script wherein one of the parameters will be the date in the format dd/mm/yyyy. My question is, how can I check if the Date passed as parameter real

Answer 1

Blockquote

DATE = "$*"

[[ "${DATE}" != @(((([123][0]|[012][1-9])|3[1])?([ \/._-])(0[13578]|1[02])?([ \/._-])(19|20)[0-9][0-9])|(([123][0]|[012][1-9])?([ \/._-])\
(0[469]|11)?([ \/._-])(19|20)[0-9][0-9])|(([12][0]|[01][1-9]|2[1-8])?([ \/._-])02?([ \/._-])(19|20)[0-9][0-9])|(29?([ \/._-])02?([ \/._-])\
(19|20(0[48]|[2468][048]|[13579][26])))) ]] && echo error || echo good)