diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/kernel/doc/src/file.xml | 10 | ||||
| -rw-r--r-- | lib/kernel/src/file.erl | 3 | ||||
| -rw-r--r-- | lib/kernel/test/file_SUITE.erl | 14 |
3 files changed, 26 insertions, 1 deletions
diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml index 1118a8feee..0a4dd3ba47 100644 --- a/lib/kernel/doc/src/file.xml +++ b/lib/kernel/doc/src/file.xml @@ -826,6 +826,16 @@ <item> <p><c>File</c> must be <c>iodata()</c>. Returns an <c>fd()</c> which lets the <c>file</c> module operate on the data in-memory as if it is a file.</p> </item> + <tag><c>sync</c></tag> + <item> + <p>On platforms that support it, enables the POSIX <c>O_SYNC</c> synchronous I/O flag or its platform-dependent + equivalent (e.g., <c>FILE_FLAG_WRITE_THROUGH</c> on Windows) so that writes to the file block until the data has + been physically written to disk. Be aware, though, that the exact semantics of this flag differ from platform to + platform; for example, neither Linux nor Windows guarantees that all file metadata are also written before the call + returns. For precise semantics, check the details of your platform's documentation. On platforms with no + support for POSIX <c>O_SYNC</c> or equivalent, use of the <c>sync</c> flag causes <c>open</c> to return + <c>{error, enotsup}</c>.</p> + </item> </taglist> <p>Returns:</p> <taglist> diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl index 5c0f3b7ceb..b5152018e0 100644 --- a/lib/kernel/src/file.erl +++ b/lib/kernel/src/file.erl @@ -95,7 +95,8 @@ Delay :: non_neg_integer()} | 'delayed_write' | {'read_ahead', Size :: pos_integer()} | 'read_ahead' | 'compressed' - | {'encoding', unicode:encoding()}. + | {'encoding', unicode:encoding()} + | sync. -type deep_list() :: [char() | atom() | deep_list()]. -type name() :: string() | atom() | deep_list(). -type name_all() :: string() | atom() | deep_list() | (RawFilename :: binary()). diff --git a/lib/kernel/test/file_SUITE.erl b/lib/kernel/test/file_SUITE.erl index e4c8f0ffaf..c75639ae7e 100644 --- a/lib/kernel/test/file_SUITE.erl +++ b/lib/kernel/test/file_SUITE.erl @@ -805,6 +805,20 @@ new_modes(Config) when is_list(Config) -> ?line {ok, [$\[]} = ?FILE_MODULE:read(Fd6, 1), ?line ok = ?FILE_MODULE:close(Fd6), + %% write and sync + case ?FILE_MODULE:open(Name1, [write, sync]) of + {ok, Fd7} -> + ok = io:write(Fd7, Marker), + ok = io:put_chars(Fd7, ".\n"), + ok = ?FILE_MODULE:close(Fd7), + {ok, Fd8} = ?FILE_MODULE:open(Name1, [read]), + {ok, Marker} = io:read(Fd8, prompt), + ok = ?FILE_MODULE:close(Fd8); + {error, enotsup} -> + %% for platforms that don't support the sync option + ok + end, + ?line [] = flush(), ?line test_server:timetrap_cancel(Dog), ok. |