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diff --git a/lib/sasl/doc/src/script.xml b/lib/sasl/doc/src/script.xml new file mode 100644 index 0000000000..6bac07d106 --- /dev/null +++ b/lib/sasl/doc/src/script.xml @@ -0,0 +1,168 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE fileref SYSTEM "fileref.dtd"> + +<fileref> + <header> + <copyright> + <year>1997</year> + <year>2007</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>script</title> + <prepared>Martin Björklund</prepared> + <responsible>Bjarne Däcker</responsible> + <docno></docno> + <approved>Bjarne Däcker</approved> + <checked></checked> + <date>97-06-03</date> + <rev>A</rev> + <file>script.sgml</file> + </header> + <file>script</file> + <filesummary>Boot script</filesummary> + <description> + <p>The <em>boot script</em> describes how the Erlang runtime system is + started. It contains instructions on which code to load and + which processes and applications to start. + </p> + <p>The command <c>erl -boot Name</c> starts the system with a boot + file called <c>Name.boot</c>, which is generated from the + <c>Name.script</c> file, using <c>systools:script2boot/1</c>. + </p> + <p>The <c>.script</c> file is generated by <c>systools</c> from a + <c>.rel</c> file and <c>.app</c> files. + </p> + </description> + + <section> + <title>FILE SYNTAX</title> + <p>The boot script is stored in a file with the extension + <c>.script</c></p> + <p>The file has the following syntax: + </p> + <code type="none"> +{script, {Name, Vsn}, + [ + {progress, loading}, + {preLoaded, [Mod1, Mod2, ...]}, + {path, [Dir1,"$ROOT/Dir",...]}. + {primLoad, [Mod1, Mod2, ...]}, + ... + {kernel_load_completed}, + {progress, loaded}, + {kernelProcess, Name, {Mod, Func, Args}}, + ... + {apply, {Mod, Func, Args}}, + ... + {progress, started}]}. </code> + <list type="bulleted"> + <item><c>Name = string()</c> defines the name of the system. + </item> + <item><c>Vsn = string()</c> defines the version of the system. + </item> + <item><c>{progress, Term}</c> sets the "progress" of the + initialization program. The function <c>init:get_status()</c> + returns the current value of the progress, which is + <c>{InternalStatus,Term}</c>. + </item> + <item> + <p><c>{path, [Dir]}</c> where <c>Dir</c> is a string. This + argument sets the load path of the system to <c>[Dir]</c>. The + load path used to load modules is obtained from the initial + load path, which is given in the script file, together with + any path flags which were supplied in the command line + arguments. The command line arguments modify the path as + follows:</p> + <list type="bulleted"> + <item><c>-pa Dir1 Dir2 ... DirN</c> adds the directories + <c>Dir1, Dir2, ..., DirN</c> to the front of the initial + load path. + </item> + <item><c>-pz Dir1 Dir2 ... DirN</c> adds the directories + <c>Dir1, Dir2, ..., DirN</c> to the end of the initial + load path. + </item> + <item> + <p><c>-path Dir1 Dir2 ... DirN</c> defines a set of + directories <c>Dir1, Dir2, ..., DirN</c> which replaces + the search path given in the script file. Directory names + in the path are interpreted as follows:</p> + <list type="bulleted"> + <item>Directory names starting with <c>/</c> are assumed + to be absolute path names. + </item> + <item>Directory names not starting with <c>/</c> are + assumed to be relative the current working directory. + </item> + <item>The special <c>$ROOT</c> variable can only be used + in the script, not as a command line argument. The + given directory is relative the Erlang installation + directory. + </item> + </list> + </item> + </list> + </item> + <item><c>{primLoad, [Mod]}</c> loads the modules <c>[Mod]</c> + from the directories specified in <c>Path</c>. The script + interpreter fetches the appropriate module by calling the + function <c>erl_prim_loader:get_file(Mod)</c>. A fatal error + which terminates the system will occur if the module cannot be + located. + </item> + <item><c>{kernel_load_completed}</c> indicates that all modules + which <em>must</em> be loaded <em>before</em> any processes + are started are loaded. In interactive mode, all + <c>{primLoad,[Mod]}</c> commands interpreted after this + command are ignored, and these modules are loaded on demand. + In embedded mode, <c>kernel_load_completed</c> is ignored, and + all modules are loaded during system start. + </item> + <item><c>{kernelProcess, Name, {Mod, Func, Args}}</c> starts a + "kernel process". The kernel process <c>Name</c> is started + by evaluating <c>apply(Mod, Func, Args)</c> which is expected + to return <c>{ok, Pid}</c> or <c>ignore</c>. The <c>init</c> + process monitors the behaviour of <c>Pid</c> and terminates + the system if <c>Pid</c> dies. Kernel processes are key + components of the runtime system. Users do not normally add + new kernel processes. + </item> + <item><c>{apply, {Mod, Func, Args}}</c>. The init process simply + evaluates <c>apply(Mod, Func, Args)</c>. The system + terminates if this results in an error. The boot procedure + hangs if this function never returns. + </item> + </list> + <note> + <p>In the <c>interactive</c> system the code loader provides + demand driven code loading, but in the <c>embedded</c> system + the code loader loads all the code immediately. The same + version of <c>code</c> is used in both cases. The code server + calls <c>init:get_argument(mode)</c> to find out if it should + run in demand mode, or non-demand driven mode. + </p> + </note> + </section> + + <section> + <title>SEE ALSO</title> + <p>systools(3) + </p> + </section> +</fileref> + |