bash - Test if variable is a date with the correct format -

bash - Test if variable is a date with the correct format -

i test if variable date (not problem), if variable have right date format (yyyy-mm-dd).

i tried :

export date_refresh=01/01/1900 if ! date -d $date_refresh "+%y-%m-%d"; echo "$date_refresh not valid date. expected format : yyyy-mm-dd" fi

but doesn't work.

i can seek :

if [[ $date_refresh == [0-9][0-9][0-9][0-9]-[0-1][0-9]-[0-3][0-9] ]]

but don't want have date 33/19/2000...

you can utilize snippet:

isvaliddate() { if [[ "$1" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]] && date -d "$1">/dev/null 2>&1; echo "valid" else echo "invalid" fi; }

testing:

isvaliddate "1900-12-25" valid isvaliddate "1900-14-25" invalid isvaliddate "01/01/1900" invalid

bash date