diff options
Diffstat (limited to 'lib/kernel/doc/src')
| -rw-r--r-- | lib/kernel/doc/src/code.xml | 11 | ||||
| -rw-r--r-- | lib/kernel/doc/src/erl_ddll.xml | 159 | ||||
| -rw-r--r-- | lib/kernel/doc/src/error_logger.xml | 5 | ||||
| -rw-r--r-- | lib/kernel/doc/src/file.xml | 6 | ||||
| -rw-r--r-- | lib/kernel/doc/src/global.xml | 12 | ||||
| -rw-r--r-- | lib/kernel/doc/src/inet.xml | 73 | ||||
| -rw-r--r-- | lib/kernel/doc/src/os.xml | 49 |
7 files changed, 156 insertions, 159 deletions
diff --git a/lib/kernel/doc/src/code.xml b/lib/kernel/doc/src/code.xml index 08d8f49ef6..279c7558bc 100644 --- a/lib/kernel/doc/src/code.xml +++ b/lib/kernel/doc/src/code.xml @@ -728,16 +728,13 @@ rpc:call(Node, code, load_binary, [Module, Filename, Binary]), </desc> </func> <func> - <name>is_module_native(Module) -> boolean() | undefined</name> + <name name="is_module_native" arity="1"/> <fsummary>Test whether a module has native code</fsummary> - <type> - <v>Module = module()</v> - </type> <desc> - <p>This function returns <c>true</c> if <c>Module</c> is + <p>This function returns <c>true</c> if <c><anno>Module</anno></c> is name of a loaded module that has native code loaded, and - <c>false</c> if <c>Module</c> is loaded but does not have - native. If <c>Module</c> is not loaded, this function returns + <c>false</c> if <c><anno>Module</anno></c> is loaded but does not have + native. If <c><anno>Module</anno></c> is not loaded, this function returns <c>undefined</c>.</p> </desc> </func> diff --git a/lib/kernel/doc/src/erl_ddll.xml b/lib/kernel/doc/src/erl_ddll.xml index 1911fb628e..26db11cfcd 100644 --- a/lib/kernel/doc/src/erl_ddll.xml +++ b/lib/kernel/doc/src/erl_ddll.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1997</year><year>2011</year> + <year>1997</year><year>2012</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -182,11 +182,8 @@ </datatypes> <funcs> <func> - <name>demonitor(MonitorRef) -> ok</name> + <name name="demonitor" arity="1"/> <fsummary>Remove a monitor for a driver</fsummary> - <type> - <v>MonitorRef = reference()</v> - </type> <desc> <p>Removes a driver monitor in much the same way as <seealso marker="erts:erlang#erlang:demonitor/1">erlang:demonitor/1</seealso> does with process @@ -232,24 +229,19 @@ </desc> </func> <func> - <name>info(Name, Tag) -> Value</name> + <name name="info" arity="2"/> <fsummary>Retrieve specific information about one driver</fsummary> - <type> - <v>Name = string() | atom()</v> - <v>Tag = processes | driver_options | port_count | linked_in_driver | permanent | awaiting_load | awaiting_unload</v> - <v>Value = term()</v> - </type> <desc> <p>This function returns specific information about one aspect - of a driver. The <c>Tag</c> parameter specifies which aspect - to get information about. The <c>Value</c> return differs + of a driver. The <c><anno>Tag</anno></c> parameter specifies which aspect + to get information about. The <c><anno>Value</anno></c> return differs between different tags:</p> <taglist> <tag><em>processes</em></tag> <item> <p>Return all processes containing <seealso marker="#users">users</seealso> of the specific drivers - as a list of tuples <c>{pid(),int()}</c>, where the - <c>int()</c> denotes the number of users in the process + as a list of tuples <c>{pid(),integer() >= 0}</c>, where the + <c>integer()</c> denotes the number of users in the process <c>pid()</c>.</p> </item> <tag><em>driver_options</em></tag> @@ -261,16 +253,16 @@ </item> <tag><em>port_count</em></tag> <item> - <p>Return the number of ports (an <c>int()</c>) using the driver.</p> + <p>Return the number of ports (an <c>integer >= 0()</c>) using the driver.</p> </item> <tag><em>linked_in_driver</em></tag> <item> - <p>Return a <c>bool()</c>, being <c>true</c> if the driver is a + <p>Return a <c>boolean()</c>, being <c>true</c> if the driver is a statically linked in one and <c>false</c> otherwise.</p> </item> <tag><em>permanent</em></tag> <item> - <p>Return a <c>bool()</c>, being <c>true</c> if the driver has made + <p>Return a <c>boolean()</c>, being <c>true</c> if the driver has made itself permanent (and is <em>not</em> a statically linked in driver). <c>false</c> otherwise.</p> </item> @@ -278,14 +270,14 @@ <item> <p>Return a list of all processes having monitors for <c>loading</c> active, each process returned as - <c>{pid(),int()}</c>, where the <c>int()</c> is the + <c>{pid(),integer() >= 0}</c>, where the <c>integer()</c> is the number of monitors held by the process <c>pid()</c>.</p> </item> <tag><em>awaiting_unload</em></tag> <item> <p>Return a list of all processes having monitors for <c>unloading</c> active, each process returned as - <c>{pid(),int()}</c>, where the <c>int()</c> is the + <c>{pid(),integer() >= 0}</c>, where the <c>integer()</c> is the number of monitors held by the process <c>pid()</c>.</p> </item> </taglist> @@ -377,41 +369,34 @@ </desc> </func> <func> - <name>monitor(Tag, Item) -> MonitorRef</name> + <name name="monitor" arity="2"/> <fsummary>Create a monitor for a driver</fsummary> - <type> - <v>Tag = driver </v> - <v>Item = {Name, When}</v> - <v>Name = atom() | string()</v> - <v>When = loaded | unloaded | unloaded_only</v> - <v>MonitorRef = reference()</v> - </type> <desc> <p>This function creates a driver monitor and works in many ways as the function <seealso marker="erts:erlang#erlang:monitor/2">erlang:monitor/2</seealso>, does for processes. When a driver changes state, the monitor results in a monitor-message being sent to the calling - process. The <c>MonitorRef</c> returned by this function is + process. The <c><anno>MonitorRef</anno></c> returned by this function is included in the message sent.</p> <p>As with process monitors, each driver monitor set will only generate <em>one single message</em>. The monitor is "destroyed" after the message is sent and there is then no need to call <seealso marker="#demonitor/1">demonitor/1</seealso>.</p> - <p>The <c>MonitorRef</c> can also be used in subsequent calls + <p>The <c><anno>MonitorRef</anno></c> can also be used in subsequent calls to <seealso marker="#demonitor/1">demonitor/1</seealso> to remove a monitor.</p> <p>The function accepts the following parameters:</p> <taglist> - <tag><em>Tag</em></tag> + <tag><em><anno>Tag</anno></em></tag> <item> <p>The monitor tag is always <c>driver</c> as this function can only be used to create driver monitors. In the future, driver monitors will be integrated with process monitors, why this parameter has to be given for consistence.</p> </item> - <tag><em>Item</em></tag> + <tag><em><anno>Item</anno></em></tag> <item> - <p>The <c>Item</c> parameter specifies which driver one + <p>The <c><anno>Item</anno></c> parameter specifies which driver one wants to monitor (the name of the driver) as well as which state change one wants to monitor. The parameter is a tuple of arity two whose first element is the @@ -588,22 +573,8 @@ </desc> </func> <func> - <name>try_load(Path, Name, OptionList) -> {ok,Status} | {ok, PendingStatus, Ref} | {error, ErrorDesc}</name> + <name name="try_load" arity="3"/> <fsummary>Load a driver</fsummary> - <type> - <v>Path = Name = string() | atom()</v> - <v>OptionList = [ Option ]</v> - <v>Option = {driver_options, DriverOptionList} | {monitor, MonitorOption} | {reload, ReloadOption}</v> - <v>DriverOptionList = [ DriverOption ]</v> - <v>DriverOption = kill_ports</v> - <v>MonitorOption = pending_driver | pending</v> - <v>ReloadOption = pending_driver | pending</v> - <v>Status = loaded | already_loaded | PendingStatus </v> - <v>PendingStatus = pending_driver | pending_process</v> - <v>Ref = reference()</v> - <v>ErrorDesc = ErrorAtom | OpaqueError</v> - <v>ErrorAtom = linked_in_driver | inconsistent | permanent | not_loaded_by_this_process | not_loaded | pending_reload | pending_process</v> - </type> <desc> <p>This function provides more control than the <c>load/2</c>/<c>reload/2</c> and @@ -655,65 +626,65 @@ <p>When the function returns <c>{ok, pending_driver}</c> or <c>{ok, pending_process}</c>, one might want to get information about when the driver is <em>actually</em> loaded. This can - be achieved by using the <c>{monitor, PendingOption}</c> option.</p> + be achieved by using the <c>{monitor, <anno>MonitorOption</anno>}</c> option.</p> <p>When monitoring is requested, and a corresponding <c>{ok, pending_driver}</c> or <c>{ok, pending_process}</c> would be - returned, the function will instead return a tuple <c>{ok, PendingStatus, reference()}</c> and the process will, at a later + returned, the function will instead return a tuple <c>{ok, <anno>PendingStatus</anno>, reference()}</c> and the process will, at a later time when the driver actually gets loaded, get a monitor message. The monitor message one can expect is described in the <seealso marker="#monitor/2">monitor/2</seealso> function description. </p> <note> <p>Note that in case of loading, monitoring can - <em>not</em> only get triggered by using the <c>{reload, ReloadOption}</c> option, but also in special cases where + <em>not</em> only get triggered by using the <c>{reload, <anno>ReloadOption</anno>}</c> option, but also in special cases where the load-error is transient, why <c>{monitor, pending_driver}</c> should be used under basically <em>all</em> real world circumstances!</p> </note> <p>The function accepts the following parameters:</p> <taglist> - <tag><em>Path</em></tag> + <tag><em><anno>Path</anno></em></tag> <item> <p>The filesystem path to the directory where the driver object file is situated. The filename of the object file (minus extension) must correspond to the driver name (used in the name parameter) and the driver must identify itself with the very same name. The - <c>Path</c> might be provided as an <em>io_list</em>, - meaning it can be a list of other io_lists, characters + <c><anno>Path</anno></c> might be provided as an <em>iolist()</em>, + meaning it can be a list of other <c>iolist()</c>s, characters (eight bit integers) or binaries, all to be flattened into a sequence of characters.</p> - <p>The (possibly flattened) <c>Path</c> parameter must be + <p>The (possibly flattened) <c><anno>Path</anno></c> parameter must be consistent throughout the system, a driver should, by all <seealso marker="#users">users</seealso>, be loaded - using the same <em>literal</em><c>Path</c>. The + using the same <em>literal</em><c><anno>Path</anno></c>. The exception is when <em>reloading</em> is requested, in - which case the <c>Path</c> may be specified + which case the <c><anno>Path</anno></c> may be specified differently. Note that all <seealso marker="#users">users</seealso> trying to load the - driver at a later time will need to use the <em>new</em><c>Path</c> if the <c>Path</c> is changed using a + driver at a later time will need to use the <em>new</em><c><anno>Path</anno></c> if the <c><anno>Path</anno></c> is changed using a <c>reload</c> option. This is yet another reason to have <em>only one loader</em> of a driver one wants to upgrade in a running system! </p> </item> - <tag><em>Name</em></tag> + <tag><em><anno>Name</anno></em></tag> <item> <p>The name parameter is the name of the driver to be used in subsequent calls to <seealso marker="erts:erlang#open_port/2">open_port</seealso>. The - name can be specified either as an <c>io_list()</c> or + name can be specified either as an <c>iolist()</c> or as an <c>atom()</c>. The name given when loading is used to find the actual object file (with the - help of the <c>Path</c> and the system implied + help of the <c><anno>Path</anno></c> and the system implied extension suffix, i.e. <c>.so</c>). The name by which the driver identifies itself must also be consistent - with this <c>Name</c> parameter, much as a beam-file's + with this <c><anno>Name</anno></c> parameter, much as a beam-file's module name much correspond to its filename.</p> </item> - <tag><em>OptionList</em></tag> + <tag><em><anno>OptionList</anno></em></tag> <item> <p>A number of options can be specified to control the loading operation. The options are given as a list of two-tuples, the tuples having the following values and meanings:</p> <taglist> - <tag><em>{driver_options, DriverOptionsList}</em></tag> + <tag><em>{driver_options, <anno>DriverOptionList</anno>}</em></tag> <item> <p>This option is to provide options that will change its general behavior and will "stick" to the driver @@ -729,14 +700,14 @@ when the last <seealso marker="#users">user</seealso> calls <seealso marker="#try_unload/2">try_unload/2</seealso>, or the last process having loaded the driver exits.</p> </item> - <tag><em>{monitor, MonitorOption}</em></tag> + <tag><em>{monitor, <anno>MonitorOption</anno>}</em></tag> <item> - <p>A <c>MonitorOption</c> tells <c>try_load/3</c> to + <p>A <c><anno>MonitorOption</anno></c> tells <c>try_load/3</c> to trigger a driver monitor under certain conditions. When the monitor is triggered, the - function will return a three-tuple <c>{ok, PendingStatus, reference()}</c>, where the <c>reference()</c> is + function will return a three-tuple <c>{ok, <anno>PendingStatus</anno>, reference()}</c>, where the <c>reference()</c> is the monitor ref for the driver monitor.</p> - <p>Only one <c>MonitorOption</c> can be specified and + <p>Only one <c><anno>MonitorOption</anno></c> can be specified and it is either the atom <c>pending</c>, which means that a monitor should be created whenever a load operation is delayed, and the atom @@ -747,7 +718,7 @@ is present for completeness, it is very well defined which reload-options might give rise to which delays. It might, however, be a good idea to use the - same <c>MonitorOption</c> as the <c>ReloadOption</c> + same <c><anno>MonitorOption</anno></c> as the <c><anno>ReloadOption</anno></c> if present.</p> <p>If reloading is not requested, it might still be useful to specify the <c>monitor</c> option, as @@ -760,12 +731,12 @@ <c>{monitor, pending_driver}</c> in production code (see the monitor discussion above). </p> </item> - <tag><em>{reload,RealoadOption}</em></tag> + <tag><em>{reload,<anno>ReloadOption</anno>}</em></tag> <item> <p>This option is used when one wants to <em>reload</em> a driver from disk, most often in a code upgrade scenario. Having a <c>reload</c> option - also implies that the <c>Path</c> parameter need + also implies that the <c><anno>Path</anno></c> parameter need <em>not</em> be consistent with earlier loads of the driver.</p> <p>To reload a driver, the process needs to have previously @@ -814,9 +785,9 @@ <tag><em>{error,inconsistent}</em></tag> <item> <p>The driver has already been loaded with either other - <c>DriverOptions</c> or a different <em>literal</em><c>Path</c> argument.</p> + <c><anno>DriverOptionList</anno></c> or a different <em>literal</em><c>Path</c> argument.</p> <p>This can happen even if a <c>reload</c> option is given, - if the <c>DriverOptions</c> differ from the current.</p> + if the <c>DriverOptionList</c> differ from the current.</p> </item> <tag><em>{error, permanent}</em></tag> <item> @@ -830,19 +801,19 @@ </item> <tag><em>{error, pending_reload}</em></tag> <item> - <p>Driver reload is already requested by another <seealso marker="#users">user</seealso> when the <c>{reload, ReloadOption}</c> option was given.</p> + <p>Driver reload is already requested by another <seealso marker="#users">user</seealso> when the <c>{reload, <anno>ReloadOption</anno>}</c> option was given.</p> </item> <tag><em>{error, not_loaded_by_this_process}</em></tag> <item> <p>Appears when the <c>reload</c> option is given. The - driver <c>Name</c> is present in the system, but there is no + driver <c><anno>Name</anno></c> is present in the system, but there is no <seealso marker="#users">user</seealso> of it in this process.</p> </item> <tag><em>{error, not_loaded}</em></tag> <item> <p>Appears when the <c>reload</c> option is given. The - driver <c>Name</c> is not in the system. Only drivers + driver <c><anno>Name</anno></c> is not in the system. Only drivers loaded by this process can be reloaded.</p> </item> </taglist> @@ -856,18 +827,8 @@ </desc> </func> <func> - <name>try_unload(Name, OptionList) -> {ok,Status} | {ok, PendingStatus, Ref} | {error, ErrorAtom}</name> + <name name="try_unload" arity="2"/> <fsummary>Unload a driver</fsummary> - <type> - <v>Name = string() | atom()</v> - <v>OptionList = [ Option ]</v> - <v>Option = {monitor, MonitorOption} | kill_ports</v> - <v>MonitorOption = pending_driver | pending</v> - <v>Status = unloaded | PendingStatus </v> - <v>PendingStatus = pending_driver | pending_process</v> - <v>Ref = reference()</v> - <v>ErrorAtom = linked_in_driver | not_loaded | not_loaded_by_this_process | permanent</v> - </type> <desc> <p>This is the low level function to unload (or decrement reference counts of) a driver. It can be used to force port @@ -948,15 +909,15 @@ </taglist> <p>The function accepts the following parameters:</p> <taglist> - <tag><em>Name</em></tag> + <tag><em><anno>Name</anno></em></tag> <item> <p>The name parameter is the name of the driver to be unloaded. The name can be specified either as an - <c>io_list()</c> or as an <c>atom()</c>. </p> + <c>iolist()</c> or as an <c>atom()</c>. </p> </item> - <tag><em>OptionList</em></tag> + <tag><em><anno>OptionList</anno></em></tag> <item> - <p>The <c>OptionList</c> argument can be used to specify + <p>The <c><anno>OptionList</anno></c> argument can be used to specify certain behavior regarding ports as well as triggering monitors under certain conditions:</p> <taglist> @@ -972,10 +933,10 @@ unloads, one should use the driver option <c>kill_ports</c> when loading the driver instead.</p> </item> - <tag><em>{monitor, MonitorOption}</em></tag> + <tag><em>{monitor, <anno>MonitorOption</anno>}</em></tag> <item> <p>This option creates a driver monitor if the condition - given in <c>MonitorOptions</c> is true. The valid + given in <c><anno>MonitorOption</anno></c> is true. The valid options are:</p> <taglist> <tag><em>pending_driver</em></tag> @@ -989,7 +950,7 @@ <c>{ok, pending_driver}</c> or <c>{ok, pending_process}</c>.</p> </item> </taglist> - <p>The <c>pending_driver</c> <c>MonitorOption</c> is by far + <p>The <c>pending_driver</c> <c><anno>MonitorOption</anno></c> is by far the most useful and it has to be used to ensure that the driver has really been unloaded and the ports closed whenever the <c>kill_ports</c> option is used or the @@ -1016,11 +977,11 @@ </item> <tag><em>{error, not_loaded}</em></tag> <item> - <p>The driver <c>Name</c> is not present in the system.</p> + <p>The driver <c><anno>Name</anno></c> is not present in the system.</p> </item> <tag><em>{error, not_loaded_by_this_process}</em></tag> <item> - <p>The driver <c>Name</c> is present in the system, but + <p>The driver <c><anno>Name</anno></c> is present in the system, but there is no <seealso marker="#users">user</seealso> of it in this process. </p> <p>As a special case, drivers can be unloaded from @@ -1088,12 +1049,8 @@ </desc> </func> <func> - <name>loaded_drivers() -> {ok, Drivers}</name> + <name name="loaded_drivers" arity="0"/> <fsummary>List loaded drivers</fsummary> - <type> - <v>Drivers = [Driver]</v> - <v>Driver = string()</v> - </type> <desc> <p>Returns a list of all the available drivers, both (statically) linked-in and dynamically loaded ones.</p> diff --git a/lib/kernel/doc/src/error_logger.xml b/lib/kernel/doc/src/error_logger.xml index ec3274965a..cd86b364f6 100644 --- a/lib/kernel/doc/src/error_logger.xml +++ b/lib/kernel/doc/src/error_logger.xml @@ -127,11 +127,8 @@ ok</pre> </desc> </func> <func> - <name>warning_map() -> Tag</name> + <name name="warning_map" arity="0"/> <fsummary>Return the current mapping for warning events</fsummary> - <type> - <v>Tag = error | warning | info</v> - </type> <desc> <p>Returns the current mapping for warning events. Events sent using <c>warning_msg/1,2</c> or <c>warning_report/1,2</c> diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml index 772eff13cc..b2a259080d 100644 --- a/lib/kernel/doc/src/file.xml +++ b/lib/kernel/doc/src/file.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2011</year> + <year>1996</year><year>2012</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -412,7 +412,7 @@ </desc> </func> <func> - <name>file_info(Filename) -> {ok, FileInfo} | {error, Reason}</name> + <name name="file_info" arity="1"/> <fsummary>Get information about a file (deprecated)</fsummary> <desc> <p>This function is obsolete. Use <c>read_file_info/1,2</c> @@ -598,7 +598,7 @@ </desc> </func> <func> - <name>native_name_encoding() -> latin1 | utf8</name> + <name name="native_name_encoding" arity="0"/> <fsummary>Return the VM's configured filename encoding.</fsummary> <desc> <p>This function returns the configured default file name encoding to use for raw file names. Generally an application supplying file names raw (as binaries), should obey the character encoding returned by this function.</p> diff --git a/lib/kernel/doc/src/global.xml b/lib/kernel/doc/src/global.xml index 304a9b1d88..9c50049503 100644 --- a/lib/kernel/doc/src/global.xml +++ b/lib/kernel/doc/src/global.xml @@ -163,7 +163,8 @@ <fsummary>Globally register a name for a pid</fsummary> <type name="method"/> <type_desc name="method">{<c>Module</c>, <c>Function</c>} - is also allowed + is currently also allowed for backward compatibility, but its use is + deprecated </type_desc> <desc> <p>Globally associates the name <c><anno>Name</anno></c> with a pid, that is, @@ -180,6 +181,15 @@ unregistered. This function is called once for each name clash.</p> + <warning> + <p>If you plan to change code without restarting your system, + you must use an external fun (<c>fun Module:Function/Arity</c>) + as the <c><anno>Resolve</anno></c> function; if you use a + local fun you can never replace the code for the module that + the fun belongs to. + </p> + </warning> + <p>There are three pre-defined resolve functions: <c>random_exit_name/3</c>, <c>random_notify_name/3</c>, and <c>notify_all_name/3</c>. If no <c><anno>Resolve</anno></c> function is diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index b727960d96..f498a88c5e 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -446,16 +446,6 @@ fe80::204:acff:fe17:bf38 faster than the receiver can read.</p> </item> - <tag><c>{bit8, clear | set | on | off}</c></tag> - <item> - <p> - Scans every byte in received data-packets and checks if the 8 bit - is set in any of them. Information is retrieved with - <c>inet:getopts/2</c>. - </p> - <p>Note that the <c>bit8</c> option is deprecated and will be removed in Erlang/OTP R16.</p> - </item> - <tag><c>{broadcast, Boolean}</c>(UDP sockets)</tag> <item> <p>Enable/disable permission to send broadcasts.</p> @@ -530,6 +520,69 @@ fe80::204:acff:fe17:bf38 </p> </item> + <tag><c>{ipv6_v6only, Boolean}</c></tag> + <item> + <p> + Restricts the socket to only use IPv6, prohibiting any + IPv4 connections. This is only applicable for + IPv6 sockets (option <c>inet6</c>). + </p> + <p> + On most platforms this option has to be set on the socket + before associating it to an address. Therefore it is only + reasonable to give it when creating the socket and not + to use it when calling the function + (<seealso marker="#setopts/2">setopts/2</seealso>) + containing this description. + </p> + <p> + The behaviour of a socket with this socket option set to + <c>true</c> is becoming the only portable one. The original + idea when IPv6 was new of using IPv6 for all traffic + is now not recommended by FreeBSD (you can use + <c>{ipv6_v6only,false}</c> to override the recommended + system default value), + forbidden by OpenBSD (the supported GENERIC kernel) + and impossible on Windows (that has separate + IPv4 and IPv6 protocol stacks). Most Linux distros + still have a system default value of <c>false</c>. + This policy shift among operating systems towards + separating IPv6 from IPv4 traffic has evolved since + it gradually proved hard and complicated to get + a dual stack implementation correct and secure. + </p> + <p> + On some platforms the only allowed value for this option + is <c>true</c>, e.g. OpenBSD and Windows. Trying to set + this option to <c>false</c> when creating the socket + will in this case fail. + </p> + <p> + Setting this option on platforms where it does not exist + is ignored and getting this option with + <seealso marker="#getopts/2">getopts/2</seealso> + returns no value i.e the returned list will not contain an + <c>{ipv6_v6only,_}</c> tuple. On Windows the option acually + does not exist, but it is emulated as being a + read-only option with the value <c>true</c>. + </p> + <p> + So it boils down to that setting this option to <c>true</c> + when creating a socket will never fail except possibly + (at the time of this writing) on a platform where you + have customized the kernel to only allow <c>false</c>, + which might be doable (but weird) on e.g. OpenBSD. + </p> + <p> + If you read back the option value using + <seealso marker="#getopts/2">getopts/2</seealso> + and get no value the option does not exist in the host OS + and all bets are off regarding the behaviour of both + an IPv6 and an IPv4 socket listening on the same port + as well as for an IPv6 socket getting IPv4 traffic. + </p> + </item> + <tag><c>{keepalive, Boolean}</c>(TCP/IP sockets)</tag> <item> <p>Enables/disables periodic transmission on a connected diff --git a/lib/kernel/doc/src/os.xml b/lib/kernel/doc/src/os.xml index f3a051c989..5e182de41d 100644 --- a/lib/kernel/doc/src/os.xml +++ b/lib/kernel/doc/src/os.xml @@ -73,7 +73,7 @@ DirOut = os:cmd("dir"), % on Win32 platform</code> </desc> </func> <func> - <name>getenv() -> [string()]</name> + <name name="getenv" arity="0"/> <fsummary>List all environment variables</fsummary> <desc> <p>Returns a list of all environment variables. @@ -87,66 +87,51 @@ DirOut = os:cmd("dir"), % on Win32 platform</code> </desc> </func> <func> - <name>getenv(VarName) -> Value | false</name> + <name name="getenv" arity="1"/> <fsummary>Get the value of an environment variable</fsummary> - <type> - <v>VarName = string() </v> - <v>Value = string()</v> - </type> <desc> - <p>Returns the <c>Value</c> of the environment variable - <c>VarName</c>, or <c>false</c> if the environment variable + <p>Returns the <c><anno>Value</anno></c> of the environment variable + <c><anno>VarName</anno></c>, or <c>false</c> if the environment variable is undefined.</p> <p>If Unicode file name encoding is in effect (see the <seealso marker="erts:erl#file_name_encoding">erl manual - page</seealso>), the strings (both <c>VarName</c> and - <c>Value</c>) may contain characters with codepoints > 255.</p> + page</seealso>), the strings (both <c><anno>VarName</anno></c> and + <c><anno>Value</anno></c>) may contain characters with codepoints > 255.</p> </desc> </func> <func> - <name>getpid() -> Value </name> + <name name="getpid" arity="0"/> <fsummary>Return the process identifier of the emulator process</fsummary> - <type> - <v>Value = string()</v> - </type> <desc> <p>Returns the process identifier of the current Erlang emulator in the format most commonly used by the operating system - environment. <c>Value</c> is returned as a string containing + environment. <c><anno>Value</anno></c> is returned as a string containing the (usually) numerical identifier for a process. On Unix, this is typically the return value of the <c>getpid()</c> - system call. On VxWorks, <c>Value</c> contains the task id - (decimal notation) of the Erlang task. On Windows, + system call. On Windows, the process id as returned by the <c>GetCurrentProcessId()</c> system call is used.</p> </desc> </func> <func> - <name>putenv(VarName, Value) -> true</name> + <name name="putenv" arity="2"/> <fsummary>Set a new value for an environment variable</fsummary> - <type> - <v>VarName = string() </v> - <v>Value = string()</v> - </type> <desc> - <p>Sets a new <c>Value</c> for the environment variable - <c>VarName</c>.</p> + <p>Sets a new <c><anno>Value</anno></c> for the environment variable + <c><anno>VarName</anno></c>.</p> <p>If Unicode filename encoding is in effect (see the <seealso marker="erts:erl#file_name_encoding">erl manual - page</seealso>), the strings (both <c>VarName</c> and - <c>Value</c>) may contain characters with codepoints > 255.</p> + page</seealso>), the strings (both <c><anno>VarName</anno></c> and + <c><anno>Value</anno></c>) may contain characters with codepoints > 255.</p> <p>On Unix platforms, the environment will be set using UTF-8 encoding if Unicode file name translation is in effect. On Windows the environment is set using wide character interfaces.</p> </desc> </func> <func> - <name>timestamp() -> Timestamp</name> + <name name="timestamp" arity="0"/> + <type_desc variable="Timestamp">Timestamp = {MegaSecs, Secs, MicroSecs}</type_desc> <fsummary>Returna a timestamp from the OS in the erlang:now/0 format</fsummary> - <type> - <v>Timestamp = {MegaSecs, Secs, MicroSecs} = <seealso marker="erts:erlang#type-timestamp">erlang:timestamp()</seealso></v> - <v>MegaSecs = Secs = MicroSecs = integer() >= 0</v> - </type> <desc> <p>Returns a tuple in the same format as <seealso marker="erts:erlang#now/0">erlang:now/0</seealso>. The difference is that this function returns what the operating system thinks (a.k.a. the wall clock time) without any attempts at time correction. The result of two different calls to this function is <em>not</em> guaranteed to be different.</p> <p>The most obvious use for this function is logging. The tuple can be used together with the function <seealso marker="stdlib:calendar#now_to_universal_time/1">calendar:now_to_universal_time/1</seealso> @@ -183,8 +168,6 @@ format_utc_timestamp() -> Solaris 1 and 2, it will be <c>sunos</c>.</p> <p>In Windows, <c><anno>Osname</anno></c> will be either <c>nt</c> (on Windows NT), or <c>windows</c> (on Windows 95).</p> - <p>On VxWorks the OS family alone is returned, that is - <c>vxworks</c>.</p> <note> <p>Think twice before using this function. Use the <c>filename</c> module if you want to inspect or build |