how to get the part before delimiter(\)

shiyiming

data a;
  input x $20.;
  cards;
  123/abc
  nba-cba009
  1-m-409_f/rt_87
  _nnt@/.com
  ....
  ;
run;
I just need the part before '/', such as
123
nba-cba009
1-m-409_f
_nnt@
....

I tried prxchange(), but looks hard to express '/' which the exact perl meta symbol '/'.
So anyone can help?
Thx million!

shiyiming

data a;
input x $20.;
cards;
123/abc
nba-cba009
1-m-409_f/rt_87
_nnt@/.com
;
run;
data b(drop=rc);
set a;
rc=find(x, '/');
if rc>0 then y=substr(x,1,rc-1);
else y=x;
run;

shiyiming

To match this special character, you must precede it with a backslash character (\).