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Citrine10
Obsidian | Level 7

Hi there,

 

How do I check if the folder is empty and if it is empty it must create a file?

 

I got the part to create a new file. I'm just stuck at the part where I need to create this file if the folder directory is completely empty

proc export 
	data=files
    outfile="C:/List.csv" 
    dbms=tab;
run;
7 REPLIES 7
sbxkoenk
SAS Super FREQ

List all files in the folder and if 0 number of files is returned, the folder is empty :

 

How to: List all the files in a folder
https://communities.sas.com/t5/SAS-Programming/How-to-List-all-the-files-in-a-folder/m-p/674065#M202...

 

Cheers,

Koen

s_lassen
Meteorite | Level 14

I think you can use the DOPEN and DNUM functions for that, e.g.

filename myfolder "<path to folder>";

data _null_;
  dir_id=dopen("myfolder");
  if dnum(dir_id)=0 then do;
       /* do what is necessary if folder is empty */
    end;
  rc=dclose(dir_id);
run;
Citrine10
Obsidian | Level 7

/*file paths*/
%let path_in= C:/Files;


data test;
dir_id=dopen("&path_in");
%if dnum(dir_id)=0 %then %do;
/* do what is necessary if folder is empty */
proc export
data=tables
outfile="C:/Files/Log.csv"
dbms=tab;
run;
%end;
rc=dclose(dir_id);
run;

Tried the above but I get an error:
ERROR: Required operator not found in expression: dnum(dir_id)=0
ERROR: Skipping to next %END statement.
Kurt_Bremser
Super User

You are mixing data step and macro code, which won't work (macro triggers are resolved before the code is handed off to the data step compiler).

Furthermore, as stated in your other thread, the PROC statement terminates the DATA step anyway.

Next, the DOPEN Function needs a file reference as argument, not a file name.

To make code conditional on the non-existence of files in a directory, you can do

%let path_in= C:/Files;

filename dref "&path_in";

%let did = %sysfunc(dopen(&dref.));

%if %sysfunc(dnum(&dref.)) = 0
%then %do;
  /* further code */
%end;
japelin
Rhodochrosite | Level 12
filename d 'c:\temp'; /* specify directory for checking */
data _null_;
  did=dopen('d');
  if did>0 then do;
    filecnt=dnum(did);
    call symputx('filecnt',filecnt);
    rc=dclose(did);
  end;
run;

%if &filecnt=0 %then %do;
  /* Describe what to do if the number of files is zero here. */
%end;
andreas_lds
Jade | Level 19

Assuming you want to export to the directory, which must be empty, you could just check if the file exists. Depending on the SAS version you are using the following code needs to be wrapped in a macro.

 

%if not %sysfunc(fileexist(c:/list.csv)) %then %do;
  < insert proc export here >
%end;
AllanBowe
Barite | Level 11

This macro will export the folder contents to a dataset:  https://core.sasjs.io/mp__dirlist_8sas.html

If the dataset is empty, the folder is empty

/Allan
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