1*17951Sserge /* @(#)ftell.c 4.3 (Berkeley) 02/13/85 */ 22011Swnj /* 32011Swnj * Return file offset. 42011Swnj * Coordinates with buffering. 52011Swnj */ 62011Swnj 72011Swnj #include <stdio.h> 82011Swnj long lseek(); 92011Swnj 102011Swnj 112011Swnj long ftell(iop) 12*17951Sserge register FILE *iop; 132011Swnj { 14*17951Sserge register long tres; 152011Swnj register adjust; 162011Swnj 172011Swnj if (iop->_cnt < 0) 182011Swnj iop->_cnt = 0; 192011Swnj if (iop->_flag&_IOREAD) 202011Swnj adjust = - iop->_cnt; 213163Stoy else if (iop->_flag&(_IOWRT|_IORW)) { 222011Swnj adjust = 0; 233163Stoy if (iop->_flag&_IOWRT && iop->_base && (iop->_flag&_IONBF)==0) 242011Swnj adjust = iop->_ptr - iop->_base; 252011Swnj } else 262011Swnj return(-1); 272011Swnj tres = lseek(fileno(iop), 0L, 1); 282011Swnj if (tres<0) 292011Swnj return(tres); 302011Swnj tres += adjust; 312011Swnj return(tres); 322011Swnj } 33