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authorSiri Hansen <[email protected]>2011-11-28 10:39:15 +0100
committerSiri Hansen <[email protected]>2011-12-01 16:15:24 +0100
commite10079c3793da3d0f6d76adaf38422cba63bc427 (patch)
tree33f7cd5fa249cf581827c84efabd4568dda3d27c
parente39c093f4cdc55084d27d378d64dd2bc464dec0b (diff)
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Fix minor faults in documentation of release handling
Fix typos or minor faults. Move out code listing of target_system.erl, and use codeinclude statement to include this file from sasl/examples directory.
-rw-r--r--lib/sasl/doc/src/release_handler.xml21
-rw-r--r--system/doc/design_principles/release_handling.xml44
-rw-r--r--system/doc/design_principles/release_structure.xml20
-rw-r--r--system/doc/system_principles/create_target.xmlsrc295
4 files changed, 84 insertions, 296 deletions
diff --git a/lib/sasl/doc/src/release_handler.xml b/lib/sasl/doc/src/release_handler.xml
index bd4a513750..e3438ede41 100644
--- a/lib/sasl/doc/src/release_handler.xml
+++ b/lib/sasl/doc/src/release_handler.xml
@@ -64,10 +64,10 @@
downgraded to the specified version by evaluating the instructions
in <c>relup</c>. An installed release can be made
<em>permanent</em>. There can only be one permanent release in
- the system, and this is the release that is used if the system is
- restarted. An installed release, except the permanent one, can be
- <em>removed</em>. When a release is removed, all files that
- belong to that release only are deleted.</p>
+ the system, and this is the release that is used if the system
+ is restarted. An installed release, except the permanent one,
+ can be <em>removed</em>. When a release is removed, all files
+ that belong to that release only are deleted.</p>
<p>Each version of the release has a status. The status can be
<c>unpacked</c>, <c>current</c>, <c>permanent</c>, or <c>old</c>.
There is always one latest release which either has status
@@ -107,16 +107,17 @@ old reboot_old permanent
restarted. This is taken care of automatically if Erlang is
started as an embedded system. Read about this in <em>Embedded System</em>. In this case, the system configuration file
<c>sys.config</c> is mandatory.</p>
- <p>A new release may restart the system. Which program to use is
- specified by the SASL configuration parameter <c>start_prg</c>
- which defaults to <c>$ROOT/bin/start</c>.</p>
+ <p>The installation of a new release may restart the system. Which
+ program to use is specified by the SASL configuration
+ parameter <c>start_prg</c> which defaults
+ to <c>$ROOT/bin/start</c>.</p>
<p>The emulator restart on Windows NT expects that the system is
started using the <c>erlsrv</c> program (as a service).
Furthermore the release handler expects that the service is named
<em>NodeName</em>_<em>Release</em>, where <em>NodeName</em> is
the first part of the Erlang nodename (up to, but not including
- the "@") and <em>Release</em> is the current release of
- the application. The release handler furthermore expects that a
+ the "@") and <em>Release</em> is the current version of
+ the release. The release handler furthermore expects that a
program like <c>start_erl.exe</c> is specified as "machine" to
<c>erlsrv</c>. During upgrading with restart, a new service will
be registered and started. The new service will be set to
@@ -484,7 +485,7 @@ release_handler:set_unpacked(RelFile, [{myapp,"1.0","/home/user"},...]).
<c>release_handler</c> to end up in an inconsistent state.</p>
<p>No persistent information is updated, why these functions can
be used on any Erlang node, embedded or not. Also, using these
- functions does not effect which code will be loaded in case of
+ functions does not affect which code will be loaded in case of
a reboot.</p>
<p>If the upgrade or downgrade fails, the application may end up
in an inconsistent state.</p>
diff --git a/system/doc/design_principles/release_handling.xml b/system/doc/design_principles/release_handling.xml
index 8ed36f3c56..4378b6599c 100644
--- a/system/doc/design_principles/release_handling.xml
+++ b/system/doc/design_principles/release_handling.xml
@@ -178,13 +178,13 @@
<marker id="instr"></marker>
<title>Release Handling Instructions</title>
<p>OTP supports a set of <em>release handling instructions</em>
- that is used when creating <c>.appup</c> files. The release
+ that are used when creating <c>.appup</c> files. The release
handler understands a subset of these, the <em>low-level</em>
instructions. To make it easier for the user, there are also a
number of <em>high-level</em> instructions, which are translated
to low-level instructions by <c>systools:make_relup</c>.</p>
<p>Here, some of the most frequently used instructions are
- described. The complete list of instructions is found in
+ described. The complete list of instructions can be found in
<c>appup(4)</c>.</p>
<p>First, some definitions:</p>
<taglist>
@@ -239,9 +239,10 @@
<p><c>update</c> with argument <c>supervisor</c> is used when
changing the start specification of a supervisor. See
<seealso marker="appup_cookbook#sup">Appup Cookbook</seealso>.</p>
- <p>The release handler finds the processes <em>using</em> a module
- to update by traversing the supervision tree of each running
- application and checking all the child specifications:</p>
+ <p>When a module is to be updated, the release handler finds
+ which processes that are <em>using</em> the module by
+ traversing the supervision tree of each running application
+ and checking all the child specifications:</p>
<code type="none">
{Id, StartFunc, Restart, Shutdown, Type, Modules}</code>
<p>A process is using a module if the name is listed in
@@ -265,8 +266,8 @@
<p>The instruction loads the module and is absolutely necessary
when running Erlang in embedded mode. It is not strictly
required when running Erlang in interactive (default) mode,
- since the code server automatically searches for and loads
- unloaded modules.</p>
+ since the code server then automatically searches for and
+ loads unloaded modules.</p>
<p>The opposite of <c>add_module</c> is <c>delete_module</c> which
unloads a module:</p>
<code type="none">
@@ -294,7 +295,7 @@
the modules are unloaded using a number of <c>delete_module</c>
instructions and then the application specification is unloaded
from the application controller.</p>
- <p>Instruction for removing an application:</p>
+ <p>Instruction for restarting an application:</p>
<code type="none">
{restart_application, Application}</code>
<p>Restarting an application means that the application is stopped
@@ -331,17 +332,17 @@
of the emulator and the core applications. Then it shuts down
the current emulator by calling <c>init:reboot()</c>, see
<c>init(3)</c>. All processes are terminated gracefully and
- the system can then be rebooted by the heart program, using
- the temporary boot file. After the reboot, the rest of the
- relup instructions are executed. This is done as a part of the
- boot script.</p>
+ the system is rebooted by the heart program, using the
+ temporary boot file. After the reboot, the rest of the relup
+ instructions are executed. This is done as a part of the
+ temporary boot script.</p>
<p>An info report is written when the upgrade is completed. To
programatically find out if the upgrade is complete,
- call <c>release_handler:which_releases/0</c> and check if the
- expected release has status <c>current</c>.</p>
- <p>The new version must be made permanent when the new emulator
- is up and running. Otherwise, the old version will be used in
- case of a new system reboot.</p>
+ call <c>release_handler:which_releases(current)</c> and check
+ if it returns the expected (i.e. the new) release.</p>
+ <p>The new release version must be made permanent when the new
+ emulator is up and running. Otherwise, the old version will be
+ used in case of a new system reboot.</p>
<p>On UNIX, the release handler tells the heart program which
command to use to reboot the system. Note that the environment
variable <c>HEART_COMMAND</c>, normally used by the heart
@@ -362,8 +363,8 @@
a relup script, and it shall always be placed at the end. If
the relup is generated by <c>systools:make_relup/3,4</c> this
is automatically ensured.</p>
- <p>When the release handler encounters the instruction, it shuts down
- the emulator by calling <c>init:reboot()</c>, see
+ <p>When the release handler encounters the instruction, it shuts
+ down the emulator by calling <c>init:reboot()</c>, see
<c>init(3)</c>. All processes are terminated gracefully and
the system can then be rebooted by the heart program using the
new release version. No more upgrade instruction will be
@@ -581,8 +582,8 @@ release_handler:remove_release(Vsn) => ok</code>
[].</code>
<p>2) Start the system as a simple target system. Note that in
reality, it should be started as an embedded system. However,
- using <c>erl</c> with the correct boot script and <c>.config</c>
- file is enough for illustration purposes:</p>
+ using <c>erl</c> with the correct boot script and config file is
+ enough for illustration purposes:</p>
<pre>
% <input>cd $ROOT</input>
% <input>bin/erl -boot $ROOT/releases/A/start -config $ROOT/releases/A/sys</input>
@@ -617,6 +618,7 @@ lib/ch_app-2/ebin/ch3.beam
releases/B/start.boot
releases/B/relup
releases/B/sys.config
+releases/B/ch_rel-2.rel
releases/ch_rel-2.rel</code>
<p>4) Copy the release package <c>ch_rel-2.tar.gz</c> to
the <c>$ROOT/releases</c> directory.</p>
diff --git a/system/doc/design_principles/release_structure.xml b/system/doc/design_principles/release_structure.xml
index 2e1daa611a..8aea0e1a10 100644
--- a/system/doc/design_principles/release_structure.xml
+++ b/system/doc/design_principles/release_structure.xml
@@ -4,7 +4,7 @@
<chapter>
<header>
<copyright>
- <year>2003</year><year>2009</year>
+ <year>2003</year><year>2011</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -61,12 +61,14 @@
{ApplicationN, AppVsnN}]}.</code>
<p>The file must be named <c>Rel.rel</c>, where <c>Rel</c> is a
unique name.</p>
- <p><c>Name</c>, <c>Vsn</c> and <c>Evsn</c> are strings.</p>
+ <p><c>Name</c>, <c>Vsn</c> and <c>EVsn</c> are strings.</p>
<p>Each <c>Application</c> (atom) and <c>AppVsn</c> (string) is
the name and version of an application included in the release.
- Note the the minimal release based on Erlang/OTP consists of
+ Note that the minimal release based on Erlang/OTP consists of
the <c>kernel</c> and <c>stdlib</c> applications, so these
applications must be included in the list.</p>
+ <p>If the release is to be upgraded, it must also include
+ the <c>sasl</c> application.</p>
<marker id="ch_rel"></marker>
<p>Example: We want to make a release of <c>ch_app</c> from
the <seealso marker="applications#ch_app">Applications</seealso>
@@ -173,6 +175,7 @@ lib/ch_app-1/ebin/ch_app.beam
lib/ch_app-1/ebin/ch_sup.beam
lib/ch_app-1/ebin/ch3.beam
releases/A/start.boot
+releases/A/ch_rel-1.rel
releases/ch_rel-1.rel</pre>
<p>Note that a new boot script was generated, without
the <c>local</c> option set, before the release package was made.
@@ -180,6 +183,17 @@ releases/ch_rel-1.rel</pre>
under <c>lib</c>. Also, we do not know where the release package
will be installed, so we do not want any hardcoded absolute paths
in the boot script here.</p>
+ <p>The release resource file <c>mysystem.rel</c> is duplicated in
+ the tar file. Originally, this file was only stored in
+ the <c>releases</c> directory in order to make it possible for
+ the <c>release_handler</c> to extract this file
+ separately. After unpacking the tar file, <c>release_handler</c>
+ would automatically copy the file
+ to <c>releases/FIRST</c>. However, sometimes the tar file is
+ unpacked without involving the <c>release_handler</c> (e.g. when
+ unpacking the first target system) and therefore the file is now
+ instead duplicated in the tar file so no manual copying is
+ necessary.</p>
<p>If a <c>relup</c> file and/or a system configuration file called
<c>sys.config</c> is found, these files are included in
the release package as well. See
diff --git a/system/doc/system_principles/create_target.xmlsrc b/system/doc/system_principles/create_target.xmlsrc
index 1564423e00..bc2a76db47 100644
--- a/system/doc/system_principles/create_target.xmlsrc
+++ b/system/doc/system_principles/create_target.xmlsrc
@@ -44,9 +44,9 @@
may be irrelevant for the purpose in question. Thus, there is a
need to be able to create a new system based on a given
Erlang/OTP system, where dispensable applications are removed,
- and a set of new applications that are included in the new
- system. Documentation and source code is irrelevant and is
- therefore not included in the new system.</p>
+ and a set of new applications are included. Documentation and
+ source code is irrelevant and is therefore not included in the
+ new system.</p>
<p>This chapter is about creating such a system, which we call a
<em>target system</em>.</p>
<p>In the following sections we consider creating target systems with
@@ -63,10 +63,11 @@
</list>
<p>We only consider the case when Erlang/OTP is running on a UNIX
system.</p>
- <p>There is an example Erlang module <c>target_system.erl</c> that
- contains functions for creating and installing a target system.
- That module is used in the examples below. The source code of
- the module is listed at the end of this chapter.</p>
+ <p>In the <c>sasl</c> application there is an example Erlang
+ module <c>target_system.erl</c> that contains functions for
+ creating and installing a target system. This module is used in
+ the examples below, and the source code of the module is listed
+ at the end of this chapter.</p>
</section>
<section>
@@ -117,28 +118,41 @@ os> <input>erl -pa /home/user/target_system/myapps/pea-1.0/ebin</input></pre>
<code type="none">
erts-5.1/bin/
releases/FIRST/start.boot
+releases/FIRST/mysystem.rel
releases/mysystem.rel
lib/kernel-2.7/
lib/stdlib-1.10/
lib/sasl-1.9.3/
lib/pea-1.0/ </code>
<p>The file <c>releases/FIRST/start.boot</c> is a copy of our
- <c>mysystem.boot</c>, and a copy of the original
- <c>mysystem.rel</c> has been put in the <c>releases</c>
- directory.</p>
+ <c>mysystem.boot</c></p>
+ <p>The release resource file <c>mysystem.rel</c> is duplicated
+ in the tar file. Originally, this file was only stored in
+ the <c>releases</c> directory in order to make it possible
+ for the <c>release_handler</c> to extract this file
+ separately. After unpacking the tar
+ file, <c>release_handler</c> would automatically copy the
+ file to <c>releases/FIRST</c>. However, sometimes the tar
+ file is unpacked without involving
+ the <c>release_handler</c> (e.g. when unpacking the first
+ target system) and therefore the file is now instead
+ duplicated in the tar file so no manual copying is
+ necessary.</p>
</item>
<item>Creates the temporary directory <c>tmp</c> and extracts the tar file
<c>mysystem.tar.gz</c> into that directory. </item>
<item>Deletes the <c>erl</c> and <c>start</c> files from
- <c>tmp/erts-5.1/bin</c>. XXX Why.</item>
+ <c>tmp/erts-5.1/bin</c>. These files will be created again from
+ source when installing the release.</item>
<item>Creates the directory <c>tmp/bin</c>.</item>
- <item>Copies the previously creates file <c>plain.boot</c> to
+ <item>Copies the previously created file <c>plain.boot</c> to
<c>tmp/bin/start.boot</c>.</item>
<item>Copies the files <c>epmd</c>, <c>run_erl</c>, and
<c>to_erl</c> from the directory <c>tmp/erts-5.1/bin</c> to
the directory <c>tmp/bin</c>.</item>
- <item>Creates the file <c>tmp/releases/start_erl.data</c> with the
- contents "5.1 FIRST".
+ <item>Creates the file <c>tmp/releases/start_erl.data</c> with
+ the contents "5.1 FIRST". This file is to be passed as data
+ file to the <c>start_erl</c> script.
</item>
<item>Recreates the file <c>mysystem.tar.gz</c> from the directories
in the directory <c>tmp</c>, and removes <c>tmp</c>.</item>
@@ -210,7 +224,7 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
file of the release version found
(<c>"releases/FIRST/start.boot"</c>).</p>
<p><c>start_erl</c> also assumes that there is <c>sys.config</c> in
- release version directory (<c>"releases/FIRST/sys.config</c>). That
+ release version directory (<c>"releases/FIRST/sys.config"</c>). That
is the topic of the next section (see below).</p>
<p>The <c>start_erl</c> shell script should normally not be
altered by the user.</p>
@@ -222,7 +236,7 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
<c>sys.config</c> in the release version directory
(<c>"releases/FIRST/sys.config"</c>). If there is no such a
file, the system start will fail. Hence such a file has to
- added as well.</p>
+ be added as well.</p>
<p></p>
<p>If you have system configuration data that are neither file
location dependent nor site dependent, it may be convenient to
@@ -245,252 +259,9 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
<section>
<title>Listing of target_system.erl</title>
- <code type="none"><![CDATA[
--module(target_system).
--include_lib("kernel/include/file.hrl").
--export([create/1, install/2]).
--define(BUFSIZE, 8192).
+ <p>This module can also be found in the <c>examples</c> directory
+ of the <c>sasl</c> application.</p>
+ <codeinclude file="../../../lib/sasl/examples/src/target_system.erl" tag="%module" type="erl"></codeinclude>
-%% Note: RelFileName below is the *stem* without trailing .rel,
-%% .script etc.
-%%
-
-%% create(RelFileName)
-%%
-create(RelFileName) ->
- RelFile = RelFileName ++ ".rel",
- io:fwrite("Reading file: \"~s\" ...~n", [RelFile]),
- {ok, [RelSpec]} = file:consult(RelFile),
- io:fwrite("Creating file: \"~s\" from \"~s\" ...~n",
- ["plain.rel", RelFile]),
- {release,
- {RelName, RelVsn},
- {erts, ErtsVsn},
- AppVsns} = RelSpec,
- PlainRelSpec = {release,
- {RelName, RelVsn},
- {erts, ErtsVsn},
- lists:filter(fun({kernel, _}) ->
- true;
- ({stdlib, _}) ->
- true;
- (_) ->
- false
- end, AppVsns)
- },
- {ok, Fd} = file:open("plain.rel", [write]),
- io:fwrite(Fd, "~p.~n", [PlainRelSpec]),
- file:close(Fd),
-
- io:fwrite("Making \"plain.script\" and \"plain.boot\" files ...~n"),
- make_script("plain"),
-
- io:fwrite("Making \"~s.script\" and \"~s.boot\" files ...~n",
- [RelFileName, RelFileName]),
- make_script(RelFileName),
-
- TarFileName = io_lib:fwrite("~s.tar.gz", [RelFileName]),
- io:fwrite("Creating tar file \"~s\" ...~n", [TarFileName]),
- make_tar(RelFileName),
-
- io:fwrite("Creating directory \"tmp\" ...~n"),
- file:make_dir("tmp"),
-
- io:fwrite("Extracting \"~s\" into directory \"tmp\" ...~n", [TarFileName]),
- extract_tar(TarFileName, "tmp"),
-
- TmpBinDir = filename:join(["tmp", "bin"]),
- ErtsBinDir = filename:join(["tmp", "erts-" ++ ErtsVsn, "bin"]),
- io:fwrite("Deleting \"erl\" and \"start\" in directory \"~s\" ...~n",
- [ErtsBinDir]),
- file:delete(filename:join([ErtsBinDir, "erl"])),
- file:delete(filename:join([ErtsBinDir, "start"])),
-
- io:fwrite("Creating temporary directory \"~s\" ...~n", [TmpBinDir]),
- file:make_dir(TmpBinDir),
-
- io:fwrite("Copying file \"plain.boot\" to \"~s\" ...~n",
- [filename:join([TmpBinDir, "start.boot"])]),
- copy_file("plain.boot", filename:join([TmpBinDir, "start.boot"])),
-
- io:fwrite("Copying files \"epmd\", \"run_erl\" and \"to_erl\" from \n"
- "\"~s\" to \"~s\" ...~n",
- [ErtsBinDir, TmpBinDir]),
- copy_file(filename:join([ErtsBinDir, "epmd"]),
- filename:join([TmpBinDir, "epmd"]), [preserve]),
- copy_file(filename:join([ErtsBinDir, "run_erl"]),
- filename:join([TmpBinDir, "run_erl"]), [preserve]),
- copy_file(filename:join([ErtsBinDir, "to_erl"]),
- filename:join([TmpBinDir, "to_erl"]), [preserve]),
-
- StartErlDataFile = filename:join(["tmp", "releases", "start_erl.data"]),
- io:fwrite("Creating \"~s\" ...~n", [StartErlDataFile]),
- StartErlData = io_lib:fwrite("~s ~s~n", [ErtsVsn, RelVsn]),
- write_file(StartErlDataFile, StartErlData),
-
- io:fwrite("Recreating tar file \"~s\" from contents in directory "
- "\"tmp\" ...~n", [TarFileName]),
- {ok, Tar} = erl_tar:open(TarFileName, [write, compressed]),
- {ok, Cwd} = file:get_cwd(),
- file:set_cwd("tmp"),
- erl_tar:add(Tar, "bin", []),
- erl_tar:add(Tar, "erts-" ++ ErtsVsn, []),
- erl_tar:add(Tar, "releases", []),
- erl_tar:add(Tar, "lib", []),
- erl_tar:close(Tar),
- file:set_cwd(Cwd),
- io:fwrite("Removing directory \"tmp\" ...~n"),
- remove_dir_tree("tmp"),
- ok.
-
-
-install(RelFileName, RootDir) ->
- TarFile = RelFileName ++ ".tar.gz",
- io:fwrite("Extracting ~s ...~n", [TarFile]),
- extract_tar(TarFile, RootDir),
- StartErlDataFile = filename:join([RootDir, "releases", "start_erl.data"]),
- {ok, StartErlData} = read_txt_file(StartErlDataFile),
- [ErlVsn, RelVsn| _] = string:tokens(StartErlData, " \n"),
- ErtsBinDir = filename:join([RootDir, "erts-" ++ ErlVsn, "bin"]),
- BinDir = filename:join([RootDir, "bin"]),
- io:fwrite("Substituting in erl.src, start.src and start_erl.src to\n"
- "form erl, start and start_erl ...\n"),
- subst_src_scripts(["erl", "start", "start_erl"], ErtsBinDir, BinDir,
- [{"FINAL_ROOTDIR", RootDir}, {"EMU", "beam"}],
- [preserve]),
- io:fwrite("Creating the RELEASES file ...\n"),
- create_RELEASES(RootDir,
- filename:join([RootDir, "releases", RelFileName])).
-
-%% LOCALS
-
-%% make_script(RelFileName)
-%%
-make_script(RelFileName) ->
- Opts = [no_module_tests],
- systools:make_script(RelFileName, Opts).
-
-%% make_tar(RelFileName)
-%%
-make_tar(RelFileName) ->
- RootDir = code:root_dir(),
- systools:make_tar(RelFileName, [{erts, RootDir}]).
-
-%% extract_tar(TarFile, DestDir)
-%%
-extract_tar(TarFile, DestDir) ->
- erl_tar:extract(TarFile, [{cwd, DestDir}, compressed]).
-
-create_RELEASES(DestDir, RelFileName) ->
- release_handler:create_RELEASES(DestDir, RelFileName ++ ".rel").
-
-subst_src_scripts(Scripts, SrcDir, DestDir, Vars, Opts) ->
- lists:foreach(fun(Script) ->
- subst_src_script(Script, SrcDir, DestDir,
- Vars, Opts)
- end, Scripts).
-
-subst_src_script(Script, SrcDir, DestDir, Vars, Opts) ->
- subst_file(filename:join([SrcDir, Script ++ ".src"]),
- filename:join([DestDir, Script]),
- Vars, Opts).
-
-subst_file(Src, Dest, Vars, Opts) ->
- {ok, Conts} = read_txt_file(Src),
- NConts = subst(Conts, Vars),
- write_file(Dest, NConts),
- case lists:member(preserve, Opts) of
- true ->
- {ok, FileInfo} = file:read_file_info(Src),
- file:write_file_info(Dest, FileInfo);
- false ->
- ok
- end.
-
-%% subst(Str, Vars)
-%% Vars = [{Var, Val}]
-%% Var = Val = string()
-%% Substitute all occurrences of %Var% for Val in Str, using the list
-%% of variables in Vars.
-%%
-subst(Str, Vars) ->
- subst(Str, Vars, []).
-
-subst([$%, C| Rest], Vars, Result) when $A =< C, C =< $Z ->
- subst_var([C| Rest], Vars, Result, []);
-subst([$%, C| Rest], Vars, Result) when $a =< C, C =< $z ->
- subst_var([C| Rest], Vars, Result, []);
-subst([$%, C| Rest], Vars, Result) when C == $_ ->
- subst_var([C| Rest], Vars, Result, []);
-subst([C| Rest], Vars, Result) ->
- subst(Rest, Vars, [C| Result]);
-subst([], _Vars, Result) ->
- lists:reverse(Result).
-
-subst_var([$%| Rest], Vars, Result, VarAcc) ->
- Key = lists:reverse(VarAcc),
- case lists:keysearch(Key, 1, Vars) of
- {value, {Key, Value}} ->
- subst(Rest, Vars, lists:reverse(Value, Result));
- false ->
- subst(Rest, Vars, [$%| VarAcc ++ [$%| Result]])
- end;
-subst_var([C| Rest], Vars, Result, VarAcc) ->
- subst_var(Rest, Vars, Result, [C| VarAcc]);
-subst_var([], Vars, Result, VarAcc) ->
- subst([], Vars, [VarAcc ++ [$%| Result]]).
-
-copy_file(Src, Dest) ->
- copy_file(Src, Dest, []).
-
-copy_file(Src, Dest, Opts) ->
- {ok, InFd} = file:open(Src, [raw, binary, read]),
- {ok, OutFd} = file:open(Dest, [raw, binary, write]),
- do_copy_file(InFd, OutFd),
- file:close(InFd),
- file:close(OutFd),
- case lists:member(preserve, Opts) of
- true ->
- {ok, FileInfo} = file:read_file_info(Src),
- file:write_file_info(Dest, FileInfo);
- false ->
- ok
- end.
-
-do_copy_file(InFd, OutFd) ->
- case file:read(InFd, ?BUFSIZE) of
- {ok, Bin} ->
- file:write(OutFd, Bin),
- do_copy_file(InFd, OutFd);
- eof ->
- ok
- end.
-
-write_file(FName, Conts) ->
- {ok, Fd} = file:open(FName, [write]),
- file:write(Fd, Conts),
- file:close(Fd).
-
-read_txt_file(File) ->
- {ok, Bin} = file:read_file(File),
- {ok, binary_to_list(Bin)}.
-
-remove_dir_tree(Dir) ->
- remove_all_files(".", [Dir]).
-
-remove_all_files(Dir, Files) ->
- lists:foreach(fun(File) ->
- FilePath = filename:join([Dir, File]),
- {ok, FileInfo} = file:read_file_info(FilePath),
- case FileInfo#file_info.type of
- directory ->
- {ok, DirFiles} = file:list_dir(FilePath),
- remove_all_files(FilePath, DirFiles),
- file:del_dir(FilePath);
- _ ->
- file:delete(FilePath)
- end
- end, Files).
- ]]></code>
</section>
</chapter>