#define NOCCARGC
#include stdio.h
extern _nextc[];
/*
** Put c back in file fd.
** Entry: c = character to put back
**        fd = file descriptor
** Returns c if successful, else EOF
*/
ungetc(c, fd) int c, fd; {
  if(!_mode(fd) || _nextc[fd]!=EOF || c==EOF) return (EOF);
  return (_nextc[fd]=c);
  }