feat: mf_trimstr macro

base/mf_trimstr.sas

@@ -0,0 +1,39 @@
+/**
+  @file mf_trimstr.sas
+  @brief Removes character(s) from the end, if they exist
+  @details If the designated characters exist at the end of the string, they 
+  are removed
+
+        %put %mf_trimstr(/blah/,/); * /blah;
+        %put %mf_trimstr(/blah/,h); * /blah/;
+        %put %mf_trimstr(/blah/,h/); */bla;
+
+  <h4> Dependencies </h4>
+
+
+  @param basestr The string to be modified
+  @param trimstr The string to be removed from the end of `basestr`, if it exists
+
+  @return output returns result with the value of `trimstr` removed from the end
+
+
+  @version 9.2
+  @author Allan Bowe
+
+**/
+
+%macro mf_trimstr(basestr,trimstr);
+%local trimlen trimval;
+%let trimlen=%length(%superq(trimstr));
+%let trimval=%qsubstr(%superq(basestr)
+  ,%length(%superq(basestr))-&trimlen+1
+  ,&trimlen);
+
+%if %superq(trimval)=%superq(trimstr) %then %do;
+  %qsubstr(%superq(basestr),1,%length(%superq(basestr))-&trimlen)
+%end;
+%else %do;
+  &basestr
+%end;
+
+%mend;