The following example uses fexist to check whether a file exists. If this is the case, it deletes it using fdelete.
Note: fdelete and fexist operate on filerefs, not on physical operating system path names. Therefore, the macro also uses a filename statement to assign the filref.
%macro deleteFile(fileName);
filename fnam "&fileName";
data _null_;
if fexist("fnam") then do;
put "&fileName exists, going to delete it.";
rc = fdelete("fnam");
end;
else do;
put "&fileName does not exist.";
put "Nothing to do!";
end;
run;
filename fnam clear;
%mend deleteFile;
systask command "touch /tmp/tq84.txt" wait;
%deleteFile(/tmp/tq84.txt)
%deleteFile(/tmp/tq84.txt)