[MAN] sync

Content-type: text/html; charset=UTF-8

SYNC

Section: User Commands (1)
Updated: January 2018
Index Return to Main Contents

---

 

NAME

sync - Synchronize cached writes to persistent storage  

SYNOPSIS

sync [,OPTION/] [,FILE/]...  

DESCRIPTION

Synchronize cached writes to persistent storage

If one or more files are specified, sync only them, or their containing file systems.

-d, --data

sync only file data, no unneeded metadata

-f, --file-system

sync the file systems that contain the files

--help

display this help and exit

--version

output version information and exit

 

BUGS

Persistence guarantees vary per system. See the system calls below for more details.  

AUTHOR

Written by Jim Meyering and Giuseppe Scrivano.  

REPORTING BUGS

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Report sync translation bugs to <http://translationproject.org/team/>  

COPYRIGHT

Copyright © 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://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.  

SEE ALSO

fdatasync(2), fsync(2), sync(2), syncfs(2)

Full documentation at: <http://www.gnu.org/software/coreutils/sync>
or available locally via: info '(coreutils) sync invocation'

---

 

Index

NAME

SYNOPSIS

DESCRIPTION

BUGS

AUTHOR

REPORTING BUGS

COPYRIGHT

SEE ALSO

---

This document was created by man2html, using the manual pages.
Time: 04:45:24 GMT, September 16, 2022 Content-type: text/html; charset=UTF-8

SYNC

Section: Linux Programmer's Manual (2)
Updated: 2017-09-15
Index Return to Main Contents

---

 

NAME

sync, syncfs - commit filesystem caches to disk  

SYNOPSIS

#include <unistd.h>

void sync(void);

int syncfs(int fd);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

sync():

_XOPEN_SOURCE >= 500
    || /* Since glibc 2.19: */ _DEFAULT_SOURCE
    || /* Glibc versions <= 2.19: */ _BSD_SOURCE

syncfs():

_GNU_SOURCE

 

DESCRIPTION

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 descriptor fd.  

RETURN VALUE

syncfs() returns 0 on success; on error, it returns -1 and sets errno to indicate the error.  

ERRORS

sync() is always successful.

syncfs() can fail for at least the following reason:

EBADF

fd is not a valid file descriptor.

 

VERSIONS

syncfs() first appeared in Linux 2.6.39; library support was added to glibc in version 2.14.  

CONFORMING TO

sync(): POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.

syncfs() is Linux-specific.  

NOTES

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 sync(void)", and sync() always returned 0.

According to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but may return before the actual writing is done. However Linux waits for I/O completions, and thus sync() or syncfs() provide the same guarantees as fsync called on every file in the system or filesystem respectively.  

BUGS

Before version 1.3.20 Linux did not wait for I/O to complete before returning.  

SEE ALSO

sync(1), fdatasync(2), fsync(2)  

COLOPHON

This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

---

 

Index

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

ERRORS

VERSIONS

CONFORMING TO

NOTES

BUGS

SEE ALSO

COLOPHON

---

This document was created by man2html, using the manual pages.
Time: 04:45:34 GMT, September 16, 2022