diff options
Diffstat (limited to 'lib/kernel/doc/src/file.xml')
| -rw-r--r-- | lib/kernel/doc/src/file.xml | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml index 50f9722a1c..c94df62d1f 100644 --- a/lib/kernel/doc/src/file.xml +++ b/lib/kernel/doc/src/file.xml @@ -1641,6 +1641,33 @@ f.txt: {person, "kalle", 25}. </desc> </func> <func> + <name>datasync(IoDevice) -> ok | {error, Reason}</name> + <fsummary>Synchronizes the in-memory data of a file, ignoring most of its metadata, with that on the physical medium</fsummary> + <type> + <v>IoDevice = io_device()</v> + <v>Reason = ext_posix() | terminated</v> + </type> + <desc> + <p>Makes sure that any buffers kept by the operating system + (not by the Erlang runtime system) are written to disk. In + many ways it's resembles fsync but it not requires to update + some of file's metadata such as the access time. On + some platforms, this function might have no effect.</p> + <p>Applications that access databases or log files often write + a tiny data fragment (e.g., one line in a log file) and then + call fsync() immediately in order to ensure that the written + data is physically stored on the harddisk. Unfortunately, fsync() + will always initiate two write operations: one for the newly + written data and another one in order to update the modification + time stored in the inode. If the modification time is not a part + of the transaction concept fdatasync() can be used to avoid + unnecessary inode disk write operations.</p> + <p>Available only in some POSIX systems. This call results in a + call to fsync(), or has no effect, in systems not implementing + the fdatasync syscall.</p> + </desc> + </func> + <func> <name>truncate(IoDevice) -> ok | {error, Reason}</name> <fsummary>Truncate a file</fsummary> <type> |