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| Rev | Author | Line No. | Line |
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| 4349 | Serge | 1 | /* |
| 2 | * Copyright (c) 1990 The Regents of the University of California. |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms are permitted |
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| 6 | * provided that the above copyright notice and this paragraph are |
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| 7 | * duplicated in all such forms and that any documentation, |
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| 8 | * advertising materials, and other materials related to such |
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| 9 | * distribution and use acknowledge that the software was developed |
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| 10 | * by the University of California, Berkeley. The name of the |
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| 11 | * University may not be used to endorse or promote products derived |
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| 12 | * from this software without specific prior written permission. |
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| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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| 15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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| 16 | */ |
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| 17 | |||
| 18 | /* |
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| 19 | FUNCTION |
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| 20 | < |
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| 21 | |||
| 22 | INDEX |
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| 23 | ftell |
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| 24 | INDEX |
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| 25 | ftello |
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| 26 | INDEX |
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| 27 | _ftell_r |
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| 28 | INDEX |
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| 29 | _ftello_r |
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| 30 | |||
| 31 | ANSI_SYNOPSIS |
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| 32 | #include |
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| 33 | long ftell(FILE *<[fp]>); |
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| 34 | off_t ftello(FILE *<[fp]>); |
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| 35 | long _ftell_r(struct _reent *<[ptr]>, FILE *<[fp]>); |
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| 36 | off_t _ftello_r(struct _reent *<[ptr]>, FILE *<[fp]>); |
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| 37 | |||
| 38 | TRAD_SYNOPSIS |
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| 39 | #include |
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| 40 | long ftell(<[fp]>) |
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| 41 | FILE *<[fp]>; |
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| 42 | |||
| 43 | off_t ftello(<[fp]>) |
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| 44 | FILE *<[fp]>; |
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| 45 | |||
| 46 | long _ftell_r(<[ptr]>, <[fp]>) |
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| 47 | struct _reent *<[ptr]>; |
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| 48 | FILE *<[fp]>; |
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| 49 | |||
| 50 | off_t _ftello_r(<[ptr]>, <[fp]>) |
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| 51 | struct _reent *<[ptr]>; |
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| 52 | FILE *<[fp]>; |
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| 53 | |||
| 54 | DESCRIPTION |
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| 55 | Objects of type < |
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| 56 | of the file your program has already read. Many of the < |
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| 57 | depend on this position, and many change it as a side effect. |
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| 58 | |||
| 59 | The result of < |
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| 60 | identified by <[fp]>. If you record this result, you can later |
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| 61 | use it with < |
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| 62 | position. The difference between < |
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| 63 | < |
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| 64 | |||
| 65 | In the current implementation, < |
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| 66 | count to represent the file position; this is the same number that |
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| 67 | would be recorded by < |
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| 68 | |||
| 69 | RETURNS |
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| 70 | < |
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| 71 | this, they return <<-1L>>. Failure occurs on streams that do not support |
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| 72 | positioning; the global < |
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| 73 | value < |
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| 74 | |||
| 75 | PORTABILITY |
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| 76 | < |
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| 77 | result (when successful) is not specified beyond requiring that it be |
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| 78 | acceptable as an argument to < |
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| 79 | conforming C implementations may return a different result from |
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| 80 | < |
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| 81 | |||
| 82 | < |
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| 83 | |||
| 84 | No supporting OS subroutines are required. |
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| 85 | */ |
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| 86 | |||
| 87 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 88 | static char sccsid[] = "%W% (Berkeley) %G%"; |
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| 89 | #endif /* LIBC_SCCS and not lint */ |
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| 90 | |||
| 91 | /* |
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| 92 | * ftell: return current offset. |
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| 93 | */ |
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| 94 | |||
| 95 | #include <_ansi.h> |
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| 96 | #include |
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| 97 | #include |
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| 98 | #include |
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| 99 | #include "local.h" |
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| 100 | |||
| 101 | long |
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| 102 | _DEFUN(_ftell_r, (ptr, fp), |
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| 103 | struct _reent *ptr _AND |
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| 104 | register FILE * fp) |
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| 105 | { |
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| 106 | _fpos_t pos; |
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| 107 | |||
| 108 | /* Ensure stdio is set up. */ |
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| 109 | |||
| 110 | CHECK_INIT (ptr, fp); |
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| 111 | |||
| 112 | _flockfile (fp); |
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| 113 | |||
| 114 | if (fp->_seek == NULL) |
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| 115 | { |
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| 116 | ptr->_errno = ESPIPE; |
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| 117 | _funlockfile (fp); |
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| 118 | return -1L; |
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| 119 | } |
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| 120 | |||
| 121 | /* Find offset of underlying I/O object, then adjust for buffered |
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| 122 | bytes. Flush a write stream, since the offset may be altered if |
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| 123 | the stream is appending. Do not flush a read stream, since we |
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| 124 | must not lose the ungetc buffer. */ |
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| 125 | if (fp->_flags & __SWR) |
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| 126 | _fflush_r (ptr, fp); |
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| 127 | if (fp->_flags & __SOFF) |
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| 128 | pos = fp->_offset; |
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| 129 | else |
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| 130 | { |
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| 131 | pos = fp->_seek (ptr, fp->_cookie, (_fpos_t) 0, SEEK_CUR); |
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| 132 | if (pos == -1L) |
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| 133 | { |
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| 134 | _funlockfile (fp); |
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| 135 | return pos; |
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| 136 | } |
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| 137 | } |
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| 138 | if (fp->_flags & __SRD) |
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| 139 | { |
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| 140 | /* |
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| 141 | * Reading. Any unread characters (including |
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| 142 | * those from ungetc) cause the position to be |
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| 143 | * smaller than that in the underlying object. |
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| 144 | */ |
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| 145 | pos -= fp->_r; |
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| 146 | if (HASUB (fp)) |
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| 147 | pos -= fp->_ur; |
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| 148 | } |
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| 149 | else if ((fp->_flags & __SWR) && fp->_p != NULL) |
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| 150 | { |
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| 151 | /* |
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| 152 | * Writing. Any buffered characters cause the |
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| 153 | * position to be greater than that in the |
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| 154 | * underlying object. |
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| 155 | */ |
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| 156 | pos += fp->_p - fp->_bf._base; |
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| 157 | } |
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| 158 | |||
| 159 | _funlockfile (fp); |
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| 160 | if ((long)pos != pos) |
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| 161 | { |
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| 162 | pos = -1; |
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| 163 | ptr->_errno = EOVERFLOW; |
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| 164 | } |
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| 165 | return pos; |
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| 166 | } |
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| 167 | |||
| 168 | #ifndef _REENT_ONLY |
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| 169 | |||
| 170 | long |
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| 171 | _DEFUN(ftell, (fp), |
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| 172 | register FILE * fp) |
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| 173 | { |
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| 174 | return _ftell_r (_REENT, fp); |
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| 175 | } |
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| 176 | |||
| 177 | #endif /* !_REENT_ONLY */ |