ref: 8188b4f4f0e07b6669e6ae3c6c1099af917eaab4
dir: /sys/src/ape/lib/ap/stdio/ftell.c/
/* * pANS stdio -- ftell */ #include "iolib.h" long ftell(FILE *f){ long seekp=lseek(f->fd, 0L, 1); if(seekp<0) return -1; /* enter error state? */ switch(f->state){ default: return seekp; case RD: return seekp-(f->wp-f->rp); case WR: return (f->flags&LINEBUF?f->lp:f->wp)-f->buf+seekp; } }