xref: /plan9/sys/src/ape/lib/ap/stdio/ftello.c (revision d9dc5dd1222af33cc62eadd05bf208e8fc0098de)
1 /*
2  * pANS stdio -- ftello
3  */
4 #include "iolib.h"
ftello(FILE * f)5 off_t ftello(FILE *f){
6 	off_t seekp=lseek(f->fd, 0L, 1);
7 	if(seekp<0) return -1;		/* enter error state? */
8 	switch(f->state){
9 	default:
10 		return seekp;
11 	case RD:
12 		return seekp-(f->wp-f->rp);
13 	case WR:
14 		return (f->flags&LINEBUF?f->lp:f->wp)-f->buf+seekp;
15 	}
16 }
17