Section (1) sync
sync — Synchronize cached writes to persistent storage
Synchronize cached writes to persistent storage
If one or more files are specified, sync only them, or their containing file systems.
sync only file data, no unneeded metadata
sync the file systems that contain the files
display this help and exit
output version information and exit
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
Full documentation <https://www.gnu.org/software/coreutils/sync>
or available locally via: info _zsingle_quotesz_(coreutils) sync invocation_zsingle_quotesz_
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
Section (2) sync
sync, syncfs — commit filesystem caches to disk
sync() causes all pending
modifications to filesystem metadata and cached file data to
be written to the underlying filesystems.
syncfs() is like
sync(), but synchronizes just
the filesystem containing file referred to by the open file
syncfs() returns 0 on
success; on error, it returns −1 and sets
errno to indicate the error.
sync() is always
syncfs() can fail for at
least the following reason:
fdis not a valid file descriptor.
syncfs() first appeared in
Linux 2.6.39; library support was added to glibc in version
Since glibc 2.2.2, the Linux prototype for
sync() is as listed above, following the
various standards. In glibc 2.2.1 and earlier, it was int
According to the standard specification (e.g.,
the writes, but may return before the actual writing is done.
However Linux waits for I/O completions, and thus
syncfs() provide the same guarantees as
fsync called on every file in the system or filesystem
This page is part of release 4.16 of the Linux
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description of the project, information about reporting bugs,
and the latest version of this page, can be found at
Copyright (c) 1992 Drew Eckhardt (drewcs.colorado.edu), March 28, 1992
and Copyright (c) 2011 Michael Kerrisk <mtk.manpagesgmail.com>
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Since the Linux kernel and libraries are constantly changing, this
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Modified by Michael Haardt <michaelmoria.de>
Modified Sat Jul 24 12:02:47 1993 by Rik Faith <faithcs.unc.edu>
Modified 15 Apr 1995 by Michael Chastain <mecshell.portal.com>:
Added reference to `bdflush(2)_zsingle_quotesz_.
Modified 960414 by Andries Brouwer <aebcwi.nl>:
Added the fact that since 1.3.20 sync actually waits.
Modified Tue Oct 22 22:27:07 1996 by Eric S. Raymond <esrthyrsus.com>
Modified 2001-10-10 by aeb, following Michael Kerrisk.
2011-09-07, mtk, Added syncfs() documentation,