| 1 | /* Detecting file changes using modification times. |
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| 2 | Copyright (C) 2017-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _FILE_CHANGE_DETECTION_H |
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| 20 | #define _FILE_CHANGE_DETECTION_H |
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| 21 | |
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| 22 | #include <stdbool.h> |
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| 23 | #include <stdio.h> |
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| 24 | #include <sys/stat.h> |
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| 25 | #include <sys/types.h> |
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| 26 | |
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| 27 | /* Items for identifying a particular file version. Excerpt from |
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| 28 | struct stat64. */ |
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| 29 | struct file_change_detection |
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| 30 | { |
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| 31 | /* Special values: 0 if file does not exist. -1 to force mismatch |
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| 32 | with the next comparison. */ |
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| 33 | off64_t size; |
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| 34 | |
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| 35 | ino64_t ino; |
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| 36 | struct __timespec64 mtime; |
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| 37 | struct __timespec64 ctime; |
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| 38 | }; |
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| 39 | |
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| 40 | /* Returns true if *LEFT and *RIGHT describe the same version of the |
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| 41 | same file. */ |
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| 42 | bool __file_is_unchanged (const struct file_change_detection *left, |
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| 43 | const struct file_change_detection *right); |
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| 44 | |
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| 45 | /* Extract file change information to *FILE from the stat buffer |
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| 46 | *ST. */ |
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| 47 | void __file_change_detection_for_stat (struct file_change_detection *file, |
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| 48 | const struct __stat64_t64 *st); |
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| 49 | |
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| 50 | /* Writes file change information for PATH to *FILE. Returns true on |
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| 51 | success. For benign errors, *FILE is cleared, and true is |
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| 52 | returned. For errors indicating resource outages and the like, |
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| 53 | false is returned. */ |
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| 54 | bool __file_change_detection_for_path (struct file_change_detection *file, |
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| 55 | const char *path); |
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| 56 | |
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| 57 | /* Writes file change information for the stream FP to *FILE. Returns |
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| 58 | ture on success, false on failure. If FP is NULL, treat the file |
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| 59 | as non-existing. */ |
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| 60 | bool __file_change_detection_for_fp (struct file_change_detection *file, |
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| 61 | FILE *fp); |
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| 62 | |
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| 63 | #ifndef _ISOMAC |
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| 64 | libc_hidden_proto (__file_is_unchanged) |
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| 65 | libc_hidden_proto (__file_change_detection_for_stat) |
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| 66 | libc_hidden_proto (__file_change_detection_for_path) |
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| 67 | libc_hidden_proto (__file_change_detection_for_fp) |
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| 68 | #endif |
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| 69 | |
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| 70 | #endif /* _FILE_CHANGE_DETECTION_H */ |
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| 71 | |
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