/sys$common/syshlp/helplib.hlb CC, Run-time functions, ungetc  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Pushes a character back into the input stream and leaves the stream
  positioned before the character.

  Syntax:

       #include <stdio.h>

       int ungetc(int character, FILE *file_pointer);