Need Help Understandind data step

[Jesusismygrace]

Hi, 

I inherited a sas program and am having difficulty understanding what the below SAS dataset is doing. Thank you in advance

libname home '/home/ijones01/projects/Lab/ad_hoc/Quest_Kit';

options compress=yes;

**Sorts the bsca_ma_weekly_report_20221005a data to use for the next step**;
Proc sort data=home.bsca_ma_weekly_report_20221005a out=member_raw nodupkey;by sub_id;
run;

data member_list;
set member_raw end=eof; /*end=eof finds the end of the file*/;
fmtname="$elig_member";
start=Sub_id;
label="*";
type='C';
output ;

if eof then do;
start = '';
hlo = 'O';
label = '';
fmtname = "$elig_member"; output;
end;
run;

[PaigeMiller]

The great thing about SAS in a lot of cases, is that if you run the code, you can figure out what it is doing.

Look at the input data set member_raw, then run the code, then look at the output data set member_list, and you will see what SAS is doing.

[ballardw · Accepted solution]

FWIW, the data set Member_list is apparently intended to create a FORMAT using the CNTLIN option of Proc format. Without Proc Format that isn't a particularly useful set.

I am going guess that there is some requirement to "mask" the identities of people as that format, named $elig_member will only display * instead of the values that appear in Sub_id.

Additionally, since that format is going to use the HLO option value of O that will also display blank for values of what ever variable besides those provided in Sub_id may appear. Because the HLO option O has to appear as the last "start" value for a format the EOF option, which does not find the end of a file but indicates when the last observation has been read, uses that EOF variable to conditionally set the label and option HLO.

[Jesusismygrace]

Thank you!!!!