1 | /* Retrieve information about a FILE stream.
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2 | Copyright (C) 2007-2022 Free Software Foundation, Inc.
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3 |
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4 | This file is free software: you can redistribute it and/or modify
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5 | it under the terms of the GNU Lesser General Public License as
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6 | published by the Free Software Foundation; either version 2.1 of the
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7 | License, or (at your option) any later version.
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8 |
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9 | This file is distributed in the hope that it will be useful,
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10 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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12 | GNU Lesser General Public License for more details.
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13 |
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14 | You should have received a copy of the GNU Lesser General Public License
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15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */
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16 |
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17 | #include <stdio.h>
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18 |
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19 | /* Return true if the stream STREAM is opened read-only, or if the
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20 | last operation on the stream was a read operation. Return false if
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21 | the stream is opened write-only or append-only, or if it supports
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22 | writing and there is no current read operation (such as fgetc).
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23 |
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24 | freading and fwriting will never both be true. If STREAM supports
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25 | both reads and writes, then:
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26 | - both freading and fwriting might be false when the stream is first
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27 | opened, after read encounters EOF, or after fflush,
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28 | - freading might be false or true and fwriting might be false
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29 | after repositioning (such as fseek, fsetpos, or rewind),
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30 | depending on the underlying implementation.
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31 |
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32 | STREAM must not be wide-character oriented. */
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33 |
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34 | #if HAVE___FREADING && (!defined __GLIBC__ || defined __UCLIBC__ || __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
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35 | /* Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.34, Android API >= 29, not glibc >= 2.2, but glibc >= 2.7, or musl libc */
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36 |
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37 | # if HAVE_STDIO_EXT_H
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38 | # include <stdio_ext.h>
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39 | # endif
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40 | # define freading(stream) (__freading (stream) != 0)
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41 |
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42 | #else
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43 |
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44 | # ifdef __cplusplus
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45 | extern "C" {
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46 | # endif
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47 |
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48 | extern bool freading (FILE *stream) _GL_ATTRIBUTE_PURE;
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49 |
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50 | # ifdef __cplusplus
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51 | }
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52 | # endif
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53 |
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54 | #endif
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