Double Looping in SAS - sas

Question

This problem might be trivial but I got stuck.
My problem is I've to go to each folder for a dataset and transpose the data.
I wrote the following code and it works fine.
OPTIONS MPRINT MLOGIC SYMBOLGEN;
%LET LOC=E:\folder;
%macro test1(k,l);
libname libary "&loc.\&k\&l.";
data dataset_&l.;
set libary.dataset_original;
run;
proc transpose data=dataset_&l. out=dataset_&l._T;
run;
%mend;
%test1(var_1,var'_1);
%test1(var_2,var'_2);
%test1(var_3,var'_3);
The issue with this code is it's not dynamic in terms of folder structure. E.g. if there's another 4 extra folders, I've to write "%test1(var_3,var'_3);"4 times.
So I tried writing the following code to make it more dynamic. But unfortunately it's not working. Can anybody please tell me where I'm making the mistake.
OPTIONS MPRINT MLOGIC SYMBOLGEN;
%LET LOC=E:\folder;
%let k=var_1 var_2 var_3;
%let l=var'_1 var'_2 var'_3;
%macro words(string);
%local count word;
%let count=1;
/* The third argument of the %QSCAN function specifies the delimiter */
%let word=%qscan(&string,&count,%str( ));
%do %while(&word ne);
%let count=%eval(&count+1);
%let word=%qscan(&string,&count,%str( ));
%end;
%eval(&count-1)
%mend words;
%macro test1(k,l);
libname libary "&loc.\&k\&l.";
data dataset_&l.;
set libary.dataset_original;
run;
proc transpose data=dataset_&l. out=dataset_&l._T;
run;
%mend;
%macro test();
%do i=1 %to %words(&k.);
%do j=1 %to %words(&l.);
%let var=%scan(&k.,&i.,str());
%let var1=%scan(&l.,&j.,str());
%test1(&var.,&var1.);
%end;
%end;
%mend;
%test();
Thanks!

Answer 1

Try this:
/* Set your base directory */
%let base = E:\Folder;
/* Pipe output from dir */
filename flist pipe "dir /s /b /a:-h &base";
/* Read files from pipe */
data files;
length file dir $ 200 name $ 50 ext $ 10;
infile flist;
input #1 file $ &;
/* File extension */
ext = scan(file, -1, ".");
/* File name */
name = scan(scan(file, -1, "\"), 1, ".");
/* Directory */
rfile = reverse(file);
dir = reverse(substr(rfile, index(rfile, "\") + 1));
/* Select only SAS datasets */
if upcase(ext) = "SAS7BDAT" then output;
drop rfile;
run;
/* Define a macro to process each file */
%macro trans_file(dir, name);
libname d "&dir";
proc transpose data = d.&name out = d.&name._t;
run;
libname d clear;
%mend trans_file;
/* Run on all files */
data _null_;
set files;
call execute(cats('%trans_file(', dir, ",", name, ");"));
run;
This gets the file list by submitting the Windows command dir. It gets all files in the specified directory and its subdirectories.
This approach then uses a simple macro that defines a data library, reads a dataset from the library, writes a transposed dataset to it, then clears it. The macro is called for each file in the list using call execute.