| 1 | /*-␊ |
| 2 | * Copyright (c) 1990, 1993␊ |
| 3 | *␉The Regents of the University of California. All rights reserved.␊ |
| 4 | *␊ |
| 5 | * This code is derived from software contributed to Berkeley by␊ |
| 6 | * Chris Torek.␊ |
| 7 | *␊ |
| 8 | * Redistribution and use in source and binary forms, with or without␊ |
| 9 | * modification, are permitted provided that the following conditions␊ |
| 10 | * are met:␊ |
| 11 | * 1. Redistributions of source code must retain the above copyright␊ |
| 12 | * notice, this list of conditions and the following disclaimer.␊ |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright␊ |
| 14 | * notice, this list of conditions and the following disclaimer in the␊ |
| 15 | * documentation and/or other materials provided with the distribution.␊ |
| 16 | * 4. Neither the name of the University nor the names of its contributors␊ |
| 17 | * may be used to endorse or promote products derived from this software␊ |
| 18 | * without specific prior written permission.␊ |
| 19 | *␊ |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND␊ |
| 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE␊ |
| 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE␊ |
| 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE␊ |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL␊ |
| 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS␊ |
| 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)␊ |
| 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT␊ |
| 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY␊ |
| 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF␊ |
| 30 | * SUCH DAMAGE.␊ |
| 31 | */␊ |
| 32 | ␊ |
| 33 | #if defined(LIBC_SCCS) && !defined(lint)␊ |
| 34 | static char sccsid[] = "@(#)ftell.c␉8.2 (Berkeley) 5/4/95";␊ |
| 35 | #endif /* LIBC_SCCS and not lint */␊ |
| 36 | #include <sys/cdefs.h>␊ |
| 37 | __FBSDID("$FreeBSD: src/lib/libc/stdio/ftell.c,v 1.27 2007/01/09 00:28:06 imp Exp $");␊ |
| 38 | ␊ |
| 39 | #include "namespace.h"␊ |
| 40 | #include <sys/types.h>␊ |
| 41 | #include <errno.h>␊ |
| 42 | #include <limits.h>␊ |
| 43 | #include <stdio.h>␊ |
| 44 | #include "un-namespace.h"␊ |
| 45 | #include "local.h"␊ |
| 46 | ␊ |
| 47 | /*␊ |
| 48 | * standard ftell function.␊ |
| 49 | */␊ |
| 50 | long␊ |
| 51 | ftell(fp)␊ |
| 52 | ␉FILE *fp;␊ |
| 53 | {␊ |
| 54 | ␉off_t rv;␊ |
| 55 | ␊ |
| 56 | ␉rv = ftello(fp);␊ |
| 57 | ␉if (rv > LONG_MAX) {␊ |
| 58 | ␉␉errno = EOVERFLOW; ␊ |
| 59 | ␉␉return (-1);␊ |
| 60 | ␉}␊ |
| 61 | ␉return (rv);␊ |
| 62 | }␊ |
| 63 | ␊ |
| 64 | /*␊ |
| 65 | * ftello: return current offset.␊ |
| 66 | */␊ |
| 67 | off_t␊ |
| 68 | ftello(fp)␊ |
| 69 | ␉FILE *fp;␊ |
| 70 | {␊ |
| 71 | ␉fpos_t rv;␊ |
| 72 | ␉int ret;␊ |
| 73 | ␊ |
| 74 | ␉ret = _ftello(fp, &rv);␊ |
| 75 | ␉if (ret)␊ |
| 76 | ␉␉return (-1);␊ |
| 77 | ␉if (rv < 0) { /* Unspecified value because of ungetc() at 0 */␊ |
| 78 | ␉␉errno = ESPIPE;␊ |
| 79 | ␉␉return (-1);␊ |
| 80 | ␉}␊ |
| 81 | ␉return (rv);␊ |
| 82 | }␊ |
| 83 | ␊ |
| 84 | int␊ |
| 85 | _ftello(fp, offset)␊ |
| 86 | ␉FILE *fp;␊ |
| 87 | ␉fpos_t *offset;␊ |
| 88 | {␊ |
| 89 | ␉fpos_t pos;␊ |
| 90 | ␉size_t n;␊ |
| 91 | ␊ |
| 92 | ␉if (fp->_seek == NULL) {␊ |
| 93 | ␉␉errno = ESPIPE;␉␉/* historic practice */␊ |
| 94 | ␉␉return (1);␊ |
| 95 | ␉}␊ |
| 96 | ␊ |
| 97 | ␉/*␊ |
| 98 | ␉ * Find offset of underlying I/O object, then␊ |
| 99 | ␉ * adjust for buffered bytes.␊ |
| 100 | ␉ */␊ |
| 101 | ␉if (__sflush(fp))␉␉/* may adjust seek offset on append stream */␊ |
| 102 | ␉␉return (1);␊ |
| 103 | ␉if (fp->_flags & __SOFF)␊ |
| 104 | ␉␉pos = fp->_offset;␊ |
| 105 | ␉else {␊ |
| 106 | ␉␉pos = _sseek(fp, (fpos_t)0, SEEK_CUR);␊ |
| 107 | ␉␉if (pos == -1)␊ |
| 108 | ␉␉␉return (1);␊ |
| 109 | ␉}␊ |
| 110 | ␉if (fp->_flags & __SRD) {␊ |
| 111 | ␉␉/*␊ |
| 112 | ␉␉ * Reading. Any unread characters (including␊ |
| 113 | ␉␉ * those from ungetc) cause the position to be␊ |
| 114 | ␉␉ * smaller than that in the underlying object.␊ |
| 115 | ␉␉ */␊ |
| 116 | ␉␉if ((pos -= (HASUB(fp) ? fp->_ur : fp->_r)) < 0) {␊ |
| 117 | ␉␉␉fp->_flags |= __SERR;␊ |
| 118 | ␉␉␉errno = EIO;␊ |
| 119 | ␉␉␉return (1);␊ |
| 120 | ␉␉}␊ |
| 121 | ␉␉if (HASUB(fp))␊ |
| 122 | ␉␉␉pos -= fp->_r; /* Can be negative at this point. */␊ |
| 123 | ␉} else if ((fp->_flags & __SWR) && fp->_p != NULL) {␊ |
| 124 | ␉␉/*␊ |
| 125 | ␉␉ * Writing. Any buffered characters cause the␊ |
| 126 | ␉␉ * position to be greater than that in the␊ |
| 127 | ␉␉ * underlying object.␊ |
| 128 | ␉␉ */␊ |
| 129 | ␉␉n = fp->_p - fp->_bf._base;␊ |
| 130 | ␉␉if (pos > OFF_MAX - n) {␊ |
| 131 | errno = EOVERFLOW;␊ |
| 132 | ␉␉␉return (1);␊ |
| 133 | ␉␉}␊ |
| 134 | ␉␉pos += n;␊ |
| 135 | ␉}␊ |
| 136 | ␉*offset = pos;␊ |
| 137 | ␉return (0);␊ |
| 138 | }␊ |
| 139 | |
