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| Rev | Author | Line No. | Line |
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| 2 | pj | 1 | /*- |
| 2 | * Copyright (c) 1990, 1993 |
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| 3 | * The Regents of the University of California. All rights reserved. |
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| 4 | * |
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| 5 | * This code is derived from software contributed to Berkeley by |
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| 6 | * Chris Torek. |
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| 7 | * |
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| 8 | * Redistribution and use in source and binary forms, with or without |
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| 9 | * modification, are permitted provided that the following conditions |
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| 10 | * are met: |
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| 11 | * 1. Redistributions of source code must retain the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer. |
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| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 14 | * notice, this list of conditions and the following disclaimer in the |
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| 15 | * documentation and/or other materials provided with the distribution. |
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| 16 | * 3. All advertising materials mentioning features or use of this software |
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| 17 | * must display the following acknowledgement: |
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| 18 | * This product includes software developed by the University of |
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| 19 | * California, Berkeley and its contributors. |
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| 20 | * 4. Neither the name of the University nor the names of its contributors |
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| 21 | * may be used to endorse or promote products derived from this software |
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| 22 | * without specific prior written permission. |
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| 23 | * |
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| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 34 | * SUCH DAMAGE. |
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| 35 | */ |
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| 36 | |||
| 37 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 38 | #if 0 |
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| 39 | static char sccsid[] = "@(#)ftell.c 8.1 (Berkeley) 6/4/93"; |
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| 40 | #endif |
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| 41 | static const char rcsid[] = |
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| 42 | "$\Id: ftell.c,v 1.5 1996/06/22 10:33:25 jraynard Exp $"; |
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| 43 | #endif /* LIBC_SCCS and not lint */ |
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| 44 | |||
| 45 | #include <stdio.h> |
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| 46 | #include <errno.h> |
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| 47 | #include "local.h" |
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| 48 | #ifdef _THREAD_SAFE |
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| 49 | #include <pthread.h> |
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| 50 | #include "pthread_private.h" |
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| 51 | #endif |
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| 52 | |||
| 53 | /* |
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| 54 | * ftell: return current offset. |
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| 55 | */ |
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| 56 | long |
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| 57 | ftell(fp) |
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| 58 | register FILE *fp; |
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| 59 | { |
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| 60 | register fpos_t pos; |
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| 61 | |||
| 62 | if (fp->_seek == NULL) { |
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| 63 | errno = ESPIPE; /* historic practice */ |
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| 64 | return (-1L); |
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| 65 | } |
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| 66 | |||
| 67 | #ifdef _THREAD_SAFE |
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| 68 | _thread_flockfile(fp, __FILE__, __LINE__); |
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| 69 | #endif |
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| 70 | /* |
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| 71 | * Find offset of underlying I/O object, then |
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| 72 | * adjust for buffered bytes. |
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| 73 | */ |
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| 74 | if (fp->_flags & __SOFF) |
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| 75 | pos = fp->_offset; |
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| 76 | else { |
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| 77 | pos = (*fp->_seek)(fp->_cookie, (fpos_t)0, SEEK_CUR); |
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| 78 | if (pos == -1) { |
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| 79 | #ifdef _THREAD_SAFE |
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| 80 | _thread_funlockfile(fp); |
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| 81 | #endif |
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| 82 | return (pos); |
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| 83 | } |
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| 84 | } |
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| 85 | if (fp->_flags & __SRD) { |
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| 86 | /* |
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| 87 | * Reading. Any unread characters (including |
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| 88 | * those from ungetc) cause the position to be |
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| 89 | * smaller than that in the underlying object. |
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| 90 | */ |
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| 91 | pos -= fp->_r; |
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| 92 | if (HASUB(fp)) |
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| 93 | pos -= fp->_ur; |
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| 94 | } else if (fp->_flags & __SWR && fp->_p != NULL) { |
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| 95 | /* |
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| 96 | * Writing. Any buffered characters cause the |
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| 97 | * position to be greater than that in the |
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| 98 | * underlying object. |
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| 99 | */ |
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| 100 | pos += fp->_p - fp->_bf._base; |
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| 101 | } |
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| 102 | #ifdef _THREAD_SAFE |
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| 103 | _thread_funlockfile(fp); |
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| 104 | #endif |
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| 105 | return (pos); |
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| 106 | } |