UNIX 6th Ed. - /usr/source/iolib/nodig.c

   1: IEH3nodg (ch)
   2: char ch;
   3: {
   4: if (IEH3digt(ch)) return (0);
   5: switch (ch)
   6:     {
   7:     case 'E':
   8:     case 'e':
   9:     case '.': case '+': case '-':
  10:         return (0);
  11:     }
  12: return (1);
  13: }

Defined functions