ctoint
ctoint(unsigned char c)
#define sgetc(p) (((p)->rd == (p)->wt) ? EOF: ctoint((int)*(p)->rd++))
#define slookc(p) (((p)->rd == (p)->wt) ? EOF: ctoint((int)*(p)->rd))
#define sbackc(p) (((p)->rd == (p)->beg) ? EOF: ctoint((int)*(--(p)->rd)))