1SYNC(2) Linux Programmer's Manual SYNC(2)
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6 sync - commit buffer cache to disk
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9 #include <unistd.h>
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11 void sync(void);
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13 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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15 sync(): _BSD_SOURCE || _XOPEN_SOURCE >= 500
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18 sync() first commits inodes to buffers, and then buffers to disk.
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21 This function is always successful.
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24 SVr4, 4.3BSD, POSIX.1-2001.
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27 Since glibc 2.2.2 the Linux prototype is as listed above, following the
28 various standards. In libc4, libc5, and glibc up to 2.2.1 it was "int
29 sync(void)", and sync() always returned 0.
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32 According to the standard specification (e.g., POSIX.1-2001), sync()
33 schedules the writes, but may return before the actual writing is done.
34 However, since version 1.3.20 Linux does actually wait. (This still
35 does not guarantee data integrity: modern disks have large caches.)
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38 bdflush(2), fdatasync(2), fsync(2), sync(8), update(8)
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41 This page is part of release 3.25 of the Linux man-pages project. A
42 description of the project, and information about reporting bugs, can
43 be found at http://www.kernel.org/doc/man-pages/.
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47Linux 2007-07-26 SYNC(2)