1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1988 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 /* 33 * Return file offset. 34 * Coordinates with buffering. 35 */ 36 #pragma weak _ftell = ftell 37 38 #include "lint.h" 39 #include "file64.h" 40 #include "mtlib.h" 41 #include <fcntl.h> 42 #include <stdio.h> 43 #include <thread.h> 44 #include <synch.h> 45 #include <errno.h> 46 #include <unistd.h> 47 #include <stddef.h> 48 #include <limits.h> 49 #include <sys/types.h> 50 #include "stdiom.h" 51 52 long 53 ftell(FILE *iop) 54 { 55 ptrdiff_t adjust; 56 off64_t tres; 57 rmutex_t *lk; 58 59 FLOCKFILE(lk, iop); 60 if (iop->_cnt < 0) 61 iop->_cnt = 0; 62 if (iop->_flag & _IOREAD) 63 adjust = (ptrdiff_t)-iop->_cnt; 64 else if (iop->_flag & (_IOWRT | _IORW)) { 65 adjust = 0; 66 if (((iop->_flag & (_IOWRT | _IONBF)) == _IOWRT) && 67 (iop->_base != 0)) 68 adjust = iop->_ptr - iop->_base; 69 else if ((iop->_flag & _IORW) && (iop->_base != 0)) 70 adjust = (ptrdiff_t)-iop->_cnt; 71 } else { 72 errno = EBADF; /* file descriptor refers to no open file */ 73 FUNLOCKFILE(lk); 74 return (EOF); 75 } 76 77 tres = lseek64(FILENO(iop), 0, SEEK_CUR); 78 if (tres >= 0) 79 tres += adjust; 80 81 if (tres > LONG_MAX) { 82 errno = EOVERFLOW; 83 FUNLOCKFILE(lk); 84 return (EOF); 85 } 86 87 FUNLOCKFILE(lk); 88 return ((long)tres); 89 } 90