1 #include "stdio_impl.h"
2 
__overflow(FILE * f,int _c)3 int __overflow(FILE* f, int _c) {
4     unsigned char c = _c;
5     if (!f->wend && __towrite(f))
6         return EOF;
7     if (f->wpos < f->wend && c != f->lbf)
8         return *f->wpos++ = c;
9     if (f->write(f, &c, 1) != 1)
10         return EOF;
11     return c;
12 }
13