path: root/lib/reltool/doc/src/reltool.xml

<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">

<erlref>
  <header>
    <copyright>
      <year>2009</year>
      <year>2012</year>
      <holder>Ericsson AB, All Rights Reserved</holder>
    </copyright>
    <legalnotice>
  The contents of this file are subject to the Erlang Public License,
  Version 1.1, (the "License"); you may not use this file except in
  compliance with the License. You should have received a copy of the
  Erlang Public License along with this software. If not, it can be
  retrieved online at http://www.erlang.org/.

  Software distributed under the License is distributed on an "AS IS"
  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  the License for the specific language governing rights and limitations
  under the License.

  The Initial Developer of the Original Code is Ericsson AB.
    </legalnotice>

    <title>reltool</title>
    <prepared>H&aring;kan Mattsson</prepared>
    <responsible>H&aring;kan Mattsson</responsible>
    <docno></docno>
    <approved>H&aring;kan Mattsson</approved>
    <checked></checked>
    <date></date>
    <rev>%VSN%</rev>
  </header>
  <module>reltool</module>
  <modulesummary>Main API of the Reltool application</modulesummary>
  <description>
    <p>This is an interface module for the Reltool application.</p>

    <p><em>Reltool</em> is a release management tool. It analyses a
    given Erlang/OTP installation and determines various dependencies
    between applications. The <c>graphical</c> frontend depicts the
    dependencies and enables interactive customization of a target
    system. The backend provides a <c>batch</c> interface for
    generation of customized target systems.</p>

    <p>The tool uses an installed Erlang/OTP system as input.
    <c>root_dir</c> is the root directory of the analysed system and
    it defaults to the system executing <c>reltool</c>. Applications
    may also be located outside <c>root_dir</c>. <c>lib_dirs</c>
    defines library directories where additional applications
    may reside and it defaults to the directories
    listed by the operating system environment variable
    <c>ERL_LIBS</c>. See the module <c>code</c> for more info.
    Finally single modules and entire applications may be read from
    Escripts.</p>

    <p>Some configuration parameters control the behavior of Reltool
    on system (<c>sys</c>) level. Others provide control on
    application (<c>app</c>) level and yet others are on module
    (<c>mod</c>) level. Module level parameters override application
    level parameters and application level parameters override system
    level parameters. Escript <c>escript</c> level parameters
    override system level parameters.</p>

    <p>The following top level <c>options</c> are supported:</p>

    <taglist>

      <tag><c>config</c></tag>
      <item>
        <p>This is the main option and it controls the configuration
           of <c>reltool</c>.  It can either be a <c>sys</c> tuple or
           a name of a <c>file</c> containing a sys tuple.</p>
      </item>

      <tag><c>trap_exit</c></tag>
      <item>
        <p>This option controls the error handling behavior of
           <c>reltool</c>.  By default the window processes traps
           exit, but this behavior can altered by setting
           <c>trap_exit</c> to <c>false</c>.</p>
      </item>

      <tag><c>wx_debug</c></tag>
      <item>
        <p>This option controls the debug level of <c>wx</c>. As its
           name indicates it is only useful for debugging. See
           <c>wx:debug/1</c> for more info.</p>
      </item>

    </taglist>

    <p>Besides the already mentioned source parameters <c>root_dir</c>
    and <c>lib_dirs</c>, the following system (<c>sys</c>) level
    options are supported:</p>

    <taglist>

      <tag><c>erts</c></tag>
      <item>
        <p>Erts specific configuration. See application level options
        below.</p>
      </item>

      <tag><c>escript</c></tag>
      <item>
        <p>Escript specific configuration. An escript has a mandatory
        file name and escript level options that are described
        below.</p>
      </item>

      <tag><c>app</c></tag>
      <item>
        <p>Application specific configuration. An application has a
        mandatory name and application level options that are
        described below.</p>
      </item>

      <tag><c>mod_cond</c></tag>
      <item>
        <p>This parameter controls the module inclusion policy. It
        defaults to <c>all</c> which means that if an application is
        included (either explicitly or implicitly) all modules in that
        application will be included. This implies that both modules
        that exist in the <c>ebin</c> directory of the application,
        as well as modules that are named in the <c>app</c> file will
        be included. If the parameter is set to <c>ebin</c>, both
        modules in the <c>ebin</c> directory and derived modules are
        included. If the parameter is set to <c>app</c>, both modules
        in the <c>app</c> file and derived modules are included.
        <c>derived</c> means that only modules that are used by other
        included modules are included. The <c>mod_cond</c> setting on
        system level is used as default for all applications.</p>
      </item>

      <tag><c>incl_cond</c></tag>
      <item>
        <p>This parameter controls the application and escript
        inclusion policy. It defaults to <c>derived</c> which means
        that the applications that do not have any explicit
        <c>incl_cond</c> setting, will only be included if any other
        (explicitly or implicitly included) application uses it. The
        value <c>include</c> implies that all applications and
        escripts that do not have any explicit <c>incl_cond</c>
        setting will be included. <c>exclude</c> implies that all
        applications and escripts) that do not have any explicit
        <c>incl_cond</c> setting will be excluded.</p>
      </item>

      <tag><c>boot_rel</c></tag>
      <item>
        <p>A target system may have several releases but the one given
        as <c>boot_rel</c> will be used as default when the system is
        booting up.</p>
      </item>

      <tag><c>rel</c></tag>
      <item>
        <p>Release specific configuration. Each release maps to a
        <c>rel</c>, <c>script</c> and <c>boot</c> file. See the
        module <c>systools</c> for more info about the details. Each
        release has a name, a version and a set of applications with a
        few release specific parameters such as type and included
        applications.</p>
      </item>

      <tag><c>relocatable</c></tag>
      <item>
        <p>This parameter controls whether the <c>erl</c> executable
        in the target system should automatically determine where it
        is installed or if it should use a hardcoded path to the
        installation. In the latter case the target system must be
        installed with <c>reltool:install/2</c> before it can be
        used. If the system is relocatable, the file tree containing
        the target system can be moved to another location without
        re-installation. The default is <c>true</c>.</p>
      </item>

      <tag><c>profile</c></tag>
      <item>
        <p>The creation of the specification for a target system is
        performed in two steps. In the first step a complete
        specification is generated. It will likely contain much more
        files than you are interested in in your customized target
        system. In the second step the specification will be filtered
        according to your filters. There you have the ability to
        specify filters per application as well as system wide
        filters. You can also select a <c>profile</c> for your
        system. Depending on the <c>profile</c>, different default
        filters will be used. There are three different profiles to
        choose from: <c>development</c>, <c>embedded</c> and
        <c>standalone</c>. <c>development</c> is default. The
        parameters that are affected by the <c>profile</c> are:
        <c>incl_sys_filters</c>, <c>excl_sys_filters</c>,
        <c>incl_app_filters</c> and <c>excl_app_filters</c>.</p>
      </item>

      <tag><c>app_file</c></tag>
      <item>
        <p>This parameter controls the default handling of the
        <c>app</c> files when a target system is generated. It
        defaults to <c>keep</c> which means that <c>app</c> files are
        copied to the target system and their contents are kept as
        they are. <c>strip</c> means that a new <c>app</c> file is
        generated from the contents of the original <c>app</c> file
        where the non included modules are removed from the
        file. <c>all</c> does also imply that a new <c>app</c> file is
        generated from the contents of the original <c>app</c> file,
        with the difference that all included modules are added to the
        file. If the application does not have any <c>app</c> file a
        file will be created for <c>all</c> but not for <c>keep</c>
        and <c>strip</c>.</p>
      </item>

      <tag><c>debug_info</c></tag>
      <item>
        <p>The <c>debug_info</c> parameter controls whether the debug
        information in the beam file should be kept (<c>keep</c>) or
        stripped <c>strip</c> when the file is copied to the target
        system.</p>
      </item>

      <tag><c>incl_sys_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which files in the system
        should be included. Each file in the target system must match
        at least one of the listed regular expressions in order to be
        included. Further the files may not match any filter in
        <c>excl_sys_filters</c> in order to be included. Which
        application files should be included is controlled with
        the parameters <c>incl_app_filters</c> and
        <c>excl_app_filters</c>. This parameter defaults to
        <c>[".*"]</c>.</p>
      </item>

      <tag><c>excl_sys_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which files in the system should
        not be included in the target system. In order to be
        included, a file must match some filter in
        <c>incl_sys_filters</c> but not any filter in
        <c>excl_sys_filters</c>. This parameter defaults to
        <c>[]</c>.</p>
      </item>
      <tag><c>incl_app_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which application specific files
        that should be included. Each file in the application must
        match at least one of the listed regular expressions in order
        to be included.  Further the files may not match any filter in
        <c>excl_app_filters</c> in order to be included. This
        parameter defaults to <c>[".*"]</c>.</p>
      </item>

      <tag><c>excl_app_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which application specific files
        should not be included in the target system. In order to
        be included, a file must match some filter in
        <c>incl_app_filters</c> but not any filter in
        <c>excl_app_filters</c>. This parameter defaults to
        <c>[]</c>.</p>
      </item>

      <tag><c>incl_archive_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which top level directories in an
        application should be included in an archive file (as
        opposed to being included as a regular directory outside the
        archive). Each top directory in the application must match at
        least one of the listed regular expressions in order to be
        included. Further the files may not match any filter in
        <c>excl_app_filters</c> in order to be included. This
        parameter defaults to <c>[".*"]</c>.</p>
      </item>

       <tag><c>excl_archive_filters</c></tag>
      <item>
        <p>This parameter normally contains a list of regular
        expressions that controls which top level directories in an
        application should not be included in an archive file. In
        order to be included in the application archive, a top
        directory must match some filter in <c>incl_archive_filters</c>
        but not any filter in <c>excl_archive_filters</c>. This
        parameter defaults to <c>["^include$","^priv$"]</c>.</p>
      </item>

      <tag><c>archive_opts</c></tag>
      <item>
        <p>This parameter contains a list of options that are given to
        <c>zip:create/3</c> when application specific files are
        packaged into an archive. Only a subset of the options are
        supported. The most useful options in this context are the ones
        that control which types of files should be compressed. This
        parameter defaults to <c>[]</c>.</p>
      </item>

    </taglist>

    <p>On application (<c>escript</c>) level, the following options are
    supported:</p>

   <taglist>
      <tag><c>incl_cond</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
    </taglist>

    <p>On application (<c>app</c>) level, the following options are
       supported:</p>

   <taglist>
      <tag><c>vsn</c></tag>
      <item>
        <p>The version of the application. In an installed system there may
        exist several versions of an application. The <c>vsn</c> parameter
        controls which version of the application will be chosen.</p>
	<p>This parameter is mutual exclusive with <c>lib_dir</c>. If
	<c>vsn</c> and <c>lib_dir</c> are both omitted, the latest version
	will be chosen.</p>
      </item>
      <tag><c>lib_dir</c></tag>
      <item>
	<p>The directory to read the application from. This parameter
	can be used to point out a specific location to fetch the
	application from. This is useful for instance if the parent
	directory for some reason is no good as a library directory on
	system level.</p>
	<p>This parameter is mutual exclusive with <c>vsn</c>. If
	<c>vsn</c> and <c>lib_dir</c> are both omitted, the latest version
	will be chosen.</p>
      </item>
      <tag><c>mod</c></tag>
      <item>
        <p>Module specific configuration. A module has a mandatory
        name and module level options that are described below.</p>
      </item>
      <tag><c>mod_cond</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
      <tag><c>incl_cond</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
      <tag><c>app_file</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
      <tag><c>debug_info</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
      <tag><c>incl_app_filters</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
      <tag><c>excl_app_filters</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>

      <tag><c>incl_archive_filters</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>

       <tag><c>excl_archive_filters</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>

     <tag><c>archive_opts</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with the
        same name on system level.</p>
      </item>
    </taglist>

     <p>On module (<c>mod</c>) level, the following options are
       supported:</p>

   <taglist>
      <tag><c>incl_cond</c></tag>
      <item>
        <p>This parameter controls whether the module is included or not. By
        default the <c>mod_incl</c> parameter on application and system level
        will be used to control whether the module is included or not. The
        value of <c>incl_cond</c> overrides the module inclusion policy.
        <c>include</c> implies that the module is included, while
        <c>exclude</c> implies that the module is not included.
        <c>derived</c> implies that the module is included if it is used
        by any other included module.</p>
      </item>
      <tag><c>debug_info</c></tag>
      <item>
        <p>The value of this parameter overrides the parameter with
        the same name on application level.</p>
      </item>
    </taglist>

  </description>

  <section>
    <title>DATA TYPES</title>
    <code type="none"><![CDATA[
options()           = [option()]
option()            = {config, config() | file()}
                    | {trap_exit, bool()}
                    | {wx_debug, term()} 
config()            = {sys, [sys()]}
sys()               = {root_dir, root_dir()}
                    | {lib_dirs, [lib_dir()]}
                    | {profile, profile()}
                    | {erts, app()}
                    | {escript, escript_file(), [escript()]}
                    | {app, app_name(), [app()]}
                    | {mod_cond, mod_cond()} 
                    | {incl_cond, incl_cond()}
                    | {boot_rel, boot_rel()}
                    | {rel, rel_name(), rel_vsn(), [rel_app()]}
                    | {relocatable, relocatable()}
                    | {app_file, app_file()}
                    | {debug_info, debug_info()}
                    | {incl_sys_filters, incl_sys_filters()}
                    | {excl_sys_filters, excl_sys_filters()}
                    | {incl_app_filters, incl_app_filters()}
                    | {excl_app_filters, excl_app_filters()}
                    | {incl_archive_filters, incl_archive_filters()}
                    | {excl_archive_filters, excl_archive_filters()}
                    | {archive_opts, [archive_opt()]}
app()               = {vsn, app_vsn()}
                    | {lib_dir, lib_dir()}
                    | {mod, mod_name(), [mod()]}
                    | {mod_cond, mod_cond()}
                    | {incl_cond, incl_cond()}
                    | {debug_info, debug_info()}
                    | {app_file, app_file()}
                    | {incl_sys_filters, incl_sys_filters()}
                    | {excl_sys_filters, excl_sys_filters()}
                    | {incl_app_filters, incl_app_filters()}
                    | {excl_app_filters, excl_app_filters()}
                    | {incl_archive_filters, incl_archive_filters()}
                    | {excl_archive_filters, excl_archive_filters()}
                    | {archive_opts, [archive_opt()]}
mod()               = {incl_cond, incl_cond()}
                    | {debug_info, debug_info()}
rel_app()           = app_name()
                    | {app_name(), app_type()} 
                    | {app_name(), [incl_app()]}
                    | {app_name(), app_type(), [incl_app()]}
app_name()          = atom()
app_type()          = permanent | transient | temporary | load | none
app_vsn()           = string()
archive_opt         = zip_create_opt()
boot_rel()          = rel_name()
app_file()          = keep | strip | all
debug_info()        = keep | strip
dir()               = string()
escript()           = {incl_cond, incl_cond()}
escript_file()      = file()
excl_app_filters()  = regexps()
excl_archive_filters() = regexps()
excl_sys_filters()  = regexps()
file()              = string()
incl_app()          = app_name()
incl_app_filters()  = regexps()
incl_archive_filters() = regexps()
incl_cond()         = include | exclude | derived
incl_sys_filters()  = regexps()
lib_dir()           = dir()
mod_cond()          = all | app | ebin | derived | none
mod_name()          = atom()
profile()           = development | embedded | standalone
re_regexp()         = string()
reason()            = string()
regexps()           = [re_regexp()]
                    | {add, [re_regexp()]}
                    | {del, [re_regexp()]}
rel_file()          = term()
rel_name()          = string()
rel_vsn()           = string()
relocatable         = boolean()
root_dir()          = dir()
script_file()       = term()
server()            = server_pid() | options()
server_pid()        = pid()
target_dir()        = file()
window_pid()        = pid()
base_dir()          = dir()
base_file()         = file()
top_dir()           = file()
top_file()          = file()
target_spec()       = [target_spec()]
                    | {create_dir, base_dir(), [target_spec()]}
                    | {create_dir, base_dir(), top_dir(), [target_spec()]}
                    | {archive, base_file(), [archive_opt()], [target_spec()]}
                    | {copy_file, base_file()}
                    | {copy_file, base_file(), top_file()}
                    | {write_file, base_file(), iolist()}
                    | {strip_beam_file, base_file()}]]></code>

    <marker id="start"></marker>
  </section>

  <funcs>
    <func>
      <name>create_target(Server, TargetDir) -> ok | {error, Reason}</name>
      <fsummary>Create a target system</fsummary>
      <type>
        <v>Server     = server()</v>
        <v>TargetDir  = target_dir()</v>
        <v>Reason     = reason()</v>
      </type>
      <desc><p>Create a target system. Gives the same result as
      <c>{ok,TargetSpec}=reltool:get_target_spec(Server)</c> and
      <c>reltool:eval_target_spec(TargetSpec,RootDir,TargetDir)</c>.</p></desc>
    </func>
    
    <func>
      <name>eval_target_spec(TargetSpec, RootDir, TargetDir) -> ok | {error, Reason}</name>
      <fsummary>Create a target system</fsummary>
      <type>
        <v>TargetSpec = target_spec()</v>
        <v>RootDir    = root_dir()</v>
        <v>TargetDir  = target_dir()</v>
        <v>Reason     = reason()</v>
      </type>
      <desc><p>Create the actual target system from a specification
      generated by <c>reltool:get_target_spec/1</c>. The creation of
      the specification for a target system is performed in two
      steps. In the first step a complete specification will be
      generated. It will likely contain much more files than you are
      interested in in your target system. In the second step the
      specification will be filtered according to your filters. There
      you have the ability to specify filters per application as well
      as system wide filters. You can also select a <c>profile</c> for
      your system. Depending on the <c>profile</c>, different default
      filters will be used.</p>

      <p>The top directories <c>bin</c>, <c>releases</c> and
      <c>lib</c> are treated differently from other files. All other
      files are by default copied to the target system. The
      <c>releases</c> directory contains generated <c>rel</c>,
      <c>script</c>, and <c>boot</c> files. The <c>lib</c> directory
      contains the applications. Which applications are included
      and if they should be customized (archived, stripped from debug
      info etc.) is specified with various configuration
      parameters. The files in the <c>bin</c> directory are copied
      from the <c>erts-vsn/bin</c> directory, but only those files
      that were originally included in the <c>bin</c> directory of the
      source system.</p>

      <p>If the configuration parameter <c>relocatable</c> was set to
      <c>true</c> there is no need to install the target system with
      <c>reltool:install/2</c> before it can be started. In that case
      the file tree containing the target system can be moved without
      re-installation.</p>

      <p>In most cases, the <c>RootDir</c> parameter should be set to
      the same as the <c>root_dir</c> configuration parameter used in
      the call to <c>reltool:get_target_spec/1</c>
      (or <c>code:root_dir()</c> if the configuration parameter is not
      set). In some cases it might be useful to evaluate the same
      target specification towards different root directories. This
      should, however, be used with great care as it requires
      equivalent file structures under all roots.</p>
      </desc>
    </func>

    <func>
      <name>get_config(Server) -> {ok, Config} | {error, Reason}</name>
      <fsummary>Get reltool configuration</fsummary>
      <type>
        <v>Server  = server()</v>
        <v>Config  = config()</v>
        <v>Reason  = reason()</v>
      </type>
      <desc><p>Get reltool configuration. Shorthand for
      <c>reltool:get_config(Server,false,false)</c>.</p></desc>
    </func>

    <func>
      <name>get_config(Server, InclDefaults, InclDerived) -> {ok, Config} | {error, Reason}</name>
      <fsummary>Get reltool configuration</fsummary>
      <type>
        <v>Server        = server()</v>
        <v>InclDefaults  = incl_defaults()</v>
        <v>InclDerived   = incl_derived()</v>
        <v>Config        = config()</v>
        <v>Reason        = reason()</v>
      </type>
      <desc><p>Get reltool configuration. Normally, only the explicit
      configuration parameters with values that differ from their
      defaults are interesting. But the builtin default values can be
      returned by setting <c>InclDefaults</c> to <c>true</c>. The
      derived configuration can be returned by setting
      <c>InclDerived</c> to <c>true</c>.</p></desc>
    </func>

    <func>
      <name>get_rel(Server, Relname) -> {ok, RelFile} | {error, Reason}</name>
      <fsummary>Get contents of a release file</fsummary>
      <type>
        <v>Server  = server()</v>
        <v>RelName = rel_name()</v>
        <v>RelFile = rel_file()</v>
        <v>Reason  = reason()</v>
      </type>
      <desc><p>Get contents of a release file. See <c>rel(4)</c> for more
      details.</p></desc>
    </func>

    <func>
      <name>get_script(Server, Relname) -> {ok, ScriptFile | {error, Reason}</name>
      <fsummary>Get contents of a boot script file</fsummary>
      <type>
        <v>Server     = server()</v>
        <v>RelName    = rel_name()</v>
        <v>ScriptFile = script_file()</v>
        <v>Reason     = reason()</v>
      </type>
      <desc><p>Get contents of a boot script file. See <c>script(4)</c> for
      more details.</p></desc>
    </func>

    <func>
      <name>get_status(Server) -> {ok, [Warning]} | {error, Reason}</name>
      <fsummary>Get contents of a release file</fsummary>
      <type>
        <v>Server  = server()</v>
        <v>Warning = string()</v>
        <v>Reason  = reason()</v>
      </type>
      <desc><p>Get status about the configuration</p></desc>
    </func>

    <func>
      <name>get_server(WindowPid) -> {ok, ServerPid} | {error, Reason}</name>
      <fsummary>Start server process with options</fsummary>
      <type>
        <v>WindowPid   = window_pid()</v>
        <v>ServerPid   = server_pid()</v>
        <v>Reason      = reason()</v>
      </type>
      <desc><p>Return the process identifier of the server process.</p></desc>
    </func>

    <func>
      <name>get_target_spec(Server) -> {ok, TargetSpec} | {error, Reason}</name>
      <fsummary>Return a specification of the target system</fsummary>
      <type>
        <v>Server     = server()</v>
        <v>TargetSpec = target_spec()</v>
        <v>Reason     = reason()</v>
      </type>
      <desc><p>Return a specification of the target system. The actual
      target system can be created with
      <c>reltool:eval_target_spec/3</c>.</p>
      </desc>
    </func>

    <func>
      <name>install(RelName, TargetDir) -> ok | {error, Reason}</name>
      <fsummary>Install a target system</fsummary>
      <type>
        <v>RelName    = rel_name()</v>
        <v>TargetDir  = target_dir()</v>
        <v>Reason     = reason()</v>
      </type>
      <desc><p>Install a created target system</p></desc>
    </func>

    <func>
      <name>start() -> {ok, WindowPid} | {error, Reason}</name>
      <fsummary>Start main window process</fsummary>
      <type>
        <v>WindowPid   = window_pid()</v>
        <v>Reason      = reason()</v>
      </type>
      <desc><p>Start a main window process with default options</p></desc>
    </func>
  
    <func>
      <name>start(Options) -> {ok, WindowPid} | {error, Reason}</name>
      <fsummary>Start main window process with options</fsummary>
      <type>
        <v>Options     = options()</v>
        <v>WindowPid   = window_pid()</v>
        <v>Reason      = reason()</v>
      </type>
      <desc><p>Start a main window process with options</p></desc>
    </func>
  
    <func>
      <name>start_link(Options) -> {ok, WindowPid} | {error, Reason}</name>
      <fsummary>Start main window process with options</fsummary>
      <type>
        <v>Options     = options()</v>
        <v>WindowPid   = window_pid()</v>
        <v>Reason      = reason()</v>
      </type>
      <desc><p>Start a main window process with options. The process is linked.</p></desc>
    </func>
  
    <func>
      <name>start_server(Options) -> {ok, ServerPid} | {error, Reason}</name>
      <fsummary>Start server process with options</fsummary>
      <type>
        <v>Options     = options()</v>
        <v>ServerPid   = server_pid()</v>
        <v>Reason      = reason()</v>
      </type>
      <desc><p>Start a server process with options. The server process
      identity can be given as an argument to several other functions in the
      API.</p></desc>
    </func>

    <func>
      <name>stop(Pid) -> ok | {error, Reason}</name>
      <fsummary>Stop a server or window process</fsummary>
      <type>
        <v>Pid     = server_pid() | window_pid()()</v>
        <v>Reason  = reason()</v>
      </type>
      <desc><p>Stop a server or window process</p></desc>
    </func>
  </funcs>
  
</erlref>