ref: cbe4b116989c0bfec49b9ae7a1d9a85ead6648ae
dir: /sys/src/cmd/rc/io.h/
#define EOF (-1) struct io{ int fd; unsigned char *buf, *bufp, *ebuf; io *next; }; io *openiofd(int), *openiostr(void), *openiocore(void*, int); void pchr(io*, int); int rchr(io*); char *rstr(io*, char*); char *closeiostr(io*); void closeio(io*); int emptyiobuf(io*); void flushio(io*); void pdec(io*, int); void poct(io*, unsigned); void pptr(io*, void*); void pquo(io*, char*); void pwrd(io*, char*); void pstr(io*, char*); void pcmd(io*, tree*); void pval(io*, word*); void pfun(io*, void(*)(void)); void pfnc(io*, thread*); void pfmt(io*, char*, ...); void vpfmt(io*, char*, va_list);