HelenOS sources

ungetc            444 uspace/lib/c/generic/stdio/scanf.c 	rc = ungetc(c, f);
ungetc            122 uspace/lib/c/include/stdio.h extern int ungetc(int, FILE *);
ungetc            122 uspace/lib/posix/include/libc/stdio.h extern int ungetc(int, FILE *);
ungetc            928 uspace/lib/sif/src/sif.c 		ungetc(c, f);
ungetc            958 uspace/lib/sif/src/sif.c 		ungetc(c, f);