Populate blank rows with previous date

[TheNovice]

I have received a dataset like below:

Dataset is sorted by Cal_date but the rows are blank after the first row is populated. I am trying to populate the remaining rows with the previous date... until the next date starts...

Cal Date	Resource Name
01/02/2019	B
.	B
.	B
01/03/2019	B

I put a variable flag = 0 where cal_date = . but i am stuck

I am trying below but not working... any direction would be appreciated

data want;
 set test;
 format newdate date9.;
      retain lag_date;
      lag_date = cal_date;
 
     if flag =1 then newdate = lag_date;
     drop lag_date;
run;

[novinosrin]

data have;
input (Cal_Date	Resource_Name) (:$10.);
cards;
01/02/2019	B
.	B
.	B
01/03/2019	B
;

data want;
 update have(obs=0) have;
 by Resource_Name;
 output;
run;

[TheNovice]

Thanks for the quick reply... i think i may have simplified it too much.. the resource_names can be different. I just need the dates to keep populating until the new dates starts

input

Cal Date	Resource Name
01/02/2019	B
.	D
.	C
01/03/2019	E
.	E

output needed

Cal Date	Resource Name
01/02/2019	B
01/02/2019	D
01/02/2019	C
01/03/2019	E
01/03/2019	E

[novinosrin · Accepted solution]

data have;
input (Cal_Date	Resource_Name) (:$10.);
cards;
01/02/2019	B
.	D
.	C
01/03/2019	E
.	E
;

data want;
 set have;
 retain _date;
 if not missing(Cal_Date) then _date=cal_date;
 else cal_date=_date;
 drop _date;
run;

[TheNovice]

It works.Thank you so much!