Rename all the variables in a data set

Some times it is necessary to rename all the variables. For example, it may be more convenient to use in array part.

An example to rename all the variables is:

data a;
input a b c d e f g h i j k l m n o p q;
cards;
1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 2 3
;
run;

proc contents data=a out=varnames;
run;

proc print data=varnames;
run;

filename pre "./pre.txt";

data _null_;
 file pre;
        set varnames end=eof;
 if _n_=1 then put "rename ";
        newvarname=trim(name)||'pre';
        put name '= ' newvarname;
 if eof then put ';';
run;

data b;
        set a;
        %include pre;
run;

proc print data=b;
run;