Skip to content
GitLab
Find file Normal viewHistoryPermalink
mod_lua.html.en 89.6 KB
Newer Older
powelld's avatar
httpd using mctls version 0.1
powelld committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head>
<meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" />
<!--
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
              This file is generated from xml source: DO NOT EDIT
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      -->
<title>mod_lua - Apache HTTP Server Version 2.4</title>
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" />
<script src="../style/scripts/prettify.min.js" type="text/javascript">
</script>

<link href="../images/favicon.ico" rel="shortcut icon" /></head>
<body>
<div id="page-header">
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
<p class="apache">Apache HTTP Server Version 2.4</p>
<img alt="" src="../images/feather.png" /></div>
<div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="../images/left.gif" /></a></div>
<div id="path">
<a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs/">Documentation</a> &gt; <a href="../">Version 2.4</a> &gt; <a href="./">Modules</a></div>
<div id="page-content">
<div id="preamble"><h1>Apache Module mod_lua</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/mod/mod_lua.html" title="English">&nbsp;en&nbsp;</a> |
<a href="../fr/mod/mod_lua.html" hreflang="fr" rel="alternate" title="Franais">&nbsp;fr&nbsp;</a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Provides Lua hooks into various portions of the httpd
request processing</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Experimental</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">ModuleIdentifier:</a></th><td>lua_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">SourceFile:</a></th><td>mod_lua.c</td></tr>
<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>2.3 and later</td></tr></table>
<h3>Summary</h3>

<p>This module allows the server to be extended with scripts written in the
Lua programming language.  The extension points (hooks) available with
<code class="module"><a href="../mod/mod_lua.html">mod_lua</a></code> include many of the hooks available to
natively compiled Apache HTTP Server modules, such as mapping requests to
files, generating dynamic responses, access control, authentication, and
authorization</p>

<p>More information on the Lua programming language can be found at the
<a href="http://www.lua.org/">the Lua website</a>.</p>

<div class="note"><code>mod_lua</code> is still in experimental state.
Until it is declared stable, usage and behavior may change
at any time, even between stable releases of the 2.4.x series.
Be sure to check the CHANGES file before upgrading.</div>

<div class="warning"><h3>Warning</h3>
<p>This module holds a great deal of power over httpd, which is both a 
strength and a potential security risk. It is <strong>not</strong> recommended 
that you use this module on a server that is shared with users you do not 
trust, as it can be abused to change the internal workings of httpd.</p>
</div>

</div>
<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><h3>Topics</h3>
<ul id="topics">
<li><img alt="" src="../images/down.gif" /> <a href="#basicconf">Basic Configuration</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writinghandlers">Writing Handlers</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writingauthzproviders">Writing Authorization Providers</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writinghooks">Writing Hooks</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#datastructures">Data Structures</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#functions">Built in functions</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#logging">Logging Functions</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#apache2">apache2 Package</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#modifying_buckets">Modifying contents with Lua filters</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#databases">Database connectivity</a></li>
</ul><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="../images/down.gif" /> <a href="#luaauthzprovider">LuaAuthzProvider</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luacodecache">LuaCodeCache</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookaccesschecker">LuaHookAccessChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookauthchecker">LuaHookAuthChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookcheckuserid">LuaHookCheckUserID</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookfixups">LuaHookFixups</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookinsertfilter">LuaHookInsertFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooklog">LuaHookLog</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookmaptostorage">LuaHookMapToStorage</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooktranslatename">LuaHookTranslateName</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooktypechecker">LuaHookTypeChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luainherit">LuaInherit</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luainputfilter">LuaInputFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luamaphandler">LuaMapHandler</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaoutputfilter">LuaOutputFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luapackagecpath">LuaPackageCPath</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luapackagepath">LuaPackagePath</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaquickhandler">LuaQuickHandler</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaroot">LuaRoot</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luascope">LuaScope</a></li>
</ul>
<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&amp;list_id=144532&amp;product=Apache%20httpd-2&amp;query_format=specific&amp;order=changeddate%20DESC%2Cpriority%2Cbug_severity&amp;component=mod_lua">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&amp;component=mod_lua">Report a bug</a></li></ul><h3>See also</h3>
<ul class="seealso">
<li><a href="#comments_section">Comments</a></li></ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="basicconf" id="basicconf">Basic Configuration</a></h2>

<p>The basic module loading directive is</p>

<pre class="prettyprint lang-config">LoadModule lua_module modules/mod_lua.so</pre>


<p>
<code>mod_lua</code> provides a handler named <code>lua-script</code>,
which can be used with a <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code> or
<code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> directive:</p>

<pre class="prettyprint lang-config">&lt;Files "*.lua"&gt;
    SetHandler lua-script
&lt;/Files&gt;</pre>


<p>
This will cause <code>mod_lua</code> to handle requests for files
ending in <code>.lua</code> by invoking that file's
<code>handle</code> function.
</p>

<p>For more flexibility, see <code class="directive">LuaMapHandler</code>.
</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="writinghandlers" id="writinghandlers">Writing Handlers</a></h2>
<p> In the Apache HTTP Server API, the handler is a specific kind of hook
responsible for generating the response.  Examples of modules that include a
handler are <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>,
and <code class="module"><a href="../mod/mod_status.html">mod_status</a></code>.</p>

<p><code>mod_lua</code> always looks to invoke a Lua function for the handler, rather than
just evaluating a script body CGI style. A handler function looks
something like this:</p>


<pre class="prettyprint lang-lua">
<strong>example.lua</strong><br />
-- example handler

require "string"

--[[
     This is the default method name for Lua handlers, see the optional
     function-name in the LuaMapHandler directive to choose a different
     entry point.
--]]
function handle(r)
    r.content_type = "text/plain"

    if r.method == 'GET' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parseargs() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'POST' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parsebody() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'PUT' then
-- use our own Error contents
        r:puts("Unsupported HTTP method " .. r.method)
        r.status = 405
        return apache2.OK
    else
-- use the ErrorDocument
        return 501
    end
    return apache2.OK
end</pre>


<p>
This handler function just prints out the uri or form encoded
arguments to a plaintext page.
</p>

<p>
This means (and in fact encourages) that you can have multiple
handlers (or hooks, or filters) in the same script.
</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="writingauthzproviders" id="writingauthzproviders">Writing Authorization Providers</a></h2>


<p><code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code> provides a high-level interface to
authorization that is much easier to use than using into the relevant
hooks directly. The first argument to the
<code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive gives
the name of the responsible authorization provider. For any
<code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> line,
<code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code> will call the authorization provider
of the given name, passing the rest of the line as parameters. The
provider will then check authorization and pass the result as return
value.</p>

<p>The authz provider is normally called before authentication. If it needs to
know the authenticated user name (or if the user will be authenticated at
all), the provider must return <code>apache2.AUTHZ_DENIED_NO_USER</code>.
This will cause authentication to proceed and the authz provider to be
called a second time.</p>

<p>The following authz provider function takes two arguments, one ip
address and one user name. It will allow access from the given ip address
without authentication, or if the authenticated user matches the second
argument:</p>

<pre class="prettyprint lang-lua">
<strong>authz_provider.lua</strong><br />

require 'apache2'

function authz_check_foo(r, ip, user)
    if r.useragent_ip == ip then
        return apache2.AUTHZ_GRANTED
    elseif r.user == nil then
        return apache2.AUTHZ_DENIED_NO_USER
    elseif r.user == user then
        return apache2.AUTHZ_GRANTED
    else
        return apache2.AUTHZ_DENIED
    end
end</pre>


<p>The following configuration registers this function as provider
<code>foo</code> and configures it for URL <code>/</code>:</p>
<pre class="prettyprint lang-config">LuaAuthzProvider foo authz_provider.lua authz_check_foo
&lt;Location "/"&gt;
  Require foo 10.1.2.3 john_doe
&lt;/Location&gt;</pre>


</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="writinghooks" id="writinghooks">Writing Hooks</a></h2>

<p>Hook functions are how modules (and Lua scripts) participate in the
processing of requests. Each type of hook exposed by the server exists for
a specific purpose, such as mapping requests to the file system,
performing access control, or setting mime types:</p>

<table class="bordered"><tr class="header">
        <th>Hook phase</th>
        <th>mod_lua directive</th>
        <th>Description</th>
    </tr>
<tr>
        <td>Quick handler</td>
        <td><code class="directive"><a href="#luaquickhandler">LuaQuickHandler</a></code></td>
        <td>This is the first hook that will be called after a request has 
            been mapped to a host or virtual host</td>
    </tr>
<tr class="odd">
        <td>Translate name</td>
        <td><code class="directive"><a href="#luahooktranslatename">LuaHookTranslateName</a></code></td>
        <td>This phase translates the requested URI into a filename on the 
            system. Modules such as <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code> and
            <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> operate in this phase.</td>
    </tr>
<tr>
        <td>Map to storage</td>
        <td><code class="directive"><a href="#luahookmaptostorage">LuaHookMapToStorage</a></code></td>
        <td>This phase maps files to their physical, cached or external/proxied storage. 
            It can be used by proxy or caching modules</td>
    </tr>
<tr class="odd">
        <td>Check Access</td>
        <td><code class="directive"><a href="#luahookaccesschecker">LuaHookAccessChecker</a></code></td>
        <td>This phase checks whether a client has access to a resource. This 
            phase is run before the user is authenticated, so beware.
        </td>
    </tr>
<tr>
        <td>Check User ID</td>
        <td><code class="directive"><a href="#luahookcheckuserid">LuaHookCheckUserID</a></code></td>
        <td>This phase it used to check the negotiated user ID</td>
    </tr>
<tr class="odd">
        <td>Check Authorization</td>
        <td><code class="directive"><a href="#luahookauthchecker">LuaHookAuthChecker</a></code> or 
            <code class="directive"><a href="#luaauthzprovider">LuaAuthzProvider</a></code></td>
        <td>This phase authorizes a user based on the negotiated credentials, such as 
            user ID, client certificate etc.
        </td>
    </tr>
<tr>
        <td>Check Type</td>
        <td><code class="directive"><a href="#luahooktypechecker">LuaHookTypeChecker</a></code></td>
        <td>This phase checks the requested file and assigns a content type and 
            a handler to it</td>
    </tr>
<tr class="odd">
        <td>Fixups</td>
        <td><code class="directive"><a href="#luahookfixups">LuaHookFixups</a></code></td>
        <td>This is the final "fix anything" phase before the content handlers 
            are run. Any last-minute changes to the request should be made here.</td>
    </tr>
<tr>
        <td>Content handler</td>
        <td>fx. <code>.lua</code> files or through <code class="directive"><a href="#luamaphandler">LuaMapHandler</a></code></td>
        <td>This is where the content is handled. Files are read, parsed, some are run, 
            and the result is sent to the client</td>
    </tr>
<tr class="odd">
        <td>Logging</td>
        <td><code class="directive"><a href="#luahooklog">LuaHookLog</a></code></td>
        <td>Once a request has been handled, it enters several logging phases, 
            which logs the request in either the error or access log. Mod_lua
            is able to hook into the start of this and control logging output.</td>
    </tr>
</table>

<p>Hook functions are passed the request object as their only argument 
(except for LuaAuthzProvider, which also gets passed the arguments from 
the Require directive).
They can return any value, depending on the hook, but most commonly
they'll return OK, DONE, or DECLINED, which you can write in Lua as
<code>apache2.OK</code>, <code>apache2.DONE</code>, or
<code>apache2.DECLINED</code>, or else an HTTP status code.</p>


<pre class="prettyprint lang-lua">
<strong>translate_name.lua</strong><br />
-- example hook that rewrites the URI to a filesystem path.

require 'apache2'

function translate_name(r)
    if r.uri == "/translate-name" then
        r.filename = r.document_root .. "/find_me.txt"
        return apache2.OK
    end
    -- we don't care about this URL, give another module a chance
    return apache2.DECLINED
end</pre>



<pre class="prettyprint lang-lua">
<strong>translate_name2.lua</strong><br />
--[[ example hook that rewrites one URI to another URI. It returns a
     apache2.DECLINED to give other URL mappers a chance to work on the
     substitution, including the core translate_name hook which maps based
     on the DocumentRoot.

     Note: Use the early/late flags in the directive to make it run before
           or after mod_alias.
--]]

require 'apache2'

function translate_name(r)
    if r.uri == "/translate-name" then
        r.uri = "/find_me.txt"
        return apache2.DECLINED
    end
    return apache2.DECLINED
end</pre>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="datastructures" id="datastructures">Data Structures</a></h2>

<dl>
<dt>request_rec</dt>
        <dd>
        <p>The request_rec is mapped in as a userdata. It has a metatable
        which lets you do useful things with it. For the most part it
        has the same fields as the request_rec struct, many of which are writable as
        well as readable.  (The table fields' content can be changed, but the
        fields themselves cannot be set to different tables.)</p>

        <table class="bordered"><tr class="header">
          <th><strong>Name</strong></th>
          <th><strong>Lua type</strong></th>
          <th><strong>Writable</strong></th>
          <th><strong>Description</strong></th>
        </tr>
<tr>
          <td><code>allowoverrides</code></td>
          <td>string</td>
          <td>no</td>
          <td>The AllowOverride options applied to the current request.</td>
        </tr>
<tr class="odd">
          <td><code>ap_auth_type</code></td>
          <td>string</td>
          <td>no</td>
          <td>If an authentication check was made, this is set to the type 
          of authentication (f.x. <code>basic</code>)</td>
        </tr>
<tr>
          <td><code>args</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The query string arguments extracted from the request 
            (f.x. <code>foo=bar&amp;name=johnsmith</code>)</td>
        </tr>
<tr class="odd">
          <td><code>assbackwards</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Set to true if this is an HTTP/0.9 style request 
            (e.g. <code>GET /foo</code> (with no headers) )</td>
        </tr>
<tr>
          <td><code>auth_name</code></td>
          <td>string</td>
          <td>no</td>
          <td>The realm name used for authorization (if applicable).</td>
        </tr>
<tr class="odd">
          <td><code>banner</code></td>
          <td>string</td>
          <td>no</td>
          <td>The server banner, f.x. <code>Apache HTTP Server/2.4.3 openssl/0.9.8c</code></td>
        </tr>
<tr>
          <td><code>basic_auth_pw</code></td>
          <td>string</td>
          <td>no</td>
          <td>The basic auth password sent with this request, if any</td>
        </tr>
<tr class="odd">
          <td><code>canonical_filename</code></td>
          <td>string</td>
          <td>no</td>
          <td>The canonical filename of the request</td>
        </tr>
<tr>
          <td><code>content_encoding</code></td>
          <td>string</td>
          <td>no</td>
          <td>The content encoding of the current request</td>
        </tr>
<tr class="odd">
          <td><code>content_type</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The content type of the current request, as determined in the 
            type_check phase (f.x. <code>image/gif</code> or <code>text/html</code>)</td>
        </tr>
<tr>
          <td><code>context_prefix</code></td>
          <td>string</td>
          <td>no</td>
          <td />
        </tr>
<tr class="odd">
          <td><code>context_document_root</code></td>
          <td>string</td>
          <td>no</td>
          <td />
        </tr>
<tr>
          <td><code>document_root</code></td>
          <td>string</td>
          <td>no</td>
          <td>The document root of the host</td>
        </tr>
<tr class="odd">
          <td><code>err_headers_out</code></td>
          <td>table</td>
          <td>no</td>
          <td>MIME header environment for the response, printed even on errors and
            persist across internal redirects</td>
        </tr>
<tr>
          <td><code>filename</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The file name that the request maps to, f.x. /www/example.com/foo.txt. This can be 
            changed in the translate-name or map-to-storage phases of a request to allow the 
            default handler (or script handlers) to serve a different file than what was requested.</td>
        </tr>
<tr class="odd">
          <td><code>handler</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The name of the <a href="../handler.html">handler</a> that should serve this request, f.x. 
            <code>lua-script</code> if it is to be served by mod_lua. This is typically set by the 
            <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> or <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code> 
            directives, but could also be set via mod_lua to allow another handler to serve up a specific request 
            that would otherwise not be served by it.
            </td>
        </tr>
<tr>
          <td><code>headers_in</code></td>
          <td>table</td>
          <td>yes</td>
          <td>MIME header environment from the request. This contains headers such as <code>Host, 
            User-Agent, Referer</code> and so on.</td>
        </tr>
<tr class="odd">
          <td><code>headers_out</code></td>
          <td>table</td>
          <td>yes</td>
          <td>MIME header environment for the response.</td>
        </tr>
<tr>
          <td><code>hostname</code></td>
          <td>string</td>
          <td>no</td>
          <td>The host name, as set by the <code>Host:</code> header or by a full URI.</td>
        </tr>
<tr class="odd">
          <td><code>is_https</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether or not this request is done via HTTPS</td>
        </tr>
<tr>
          <td><code>is_initial_req</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether this request is the initial request or a sub-request</td>
        </tr>
<tr class="odd">
          <td><code>limit_req_body</code></td>
          <td>number</td>
          <td>no</td>
          <td>The size limit of the request body for this request, or 0 if no limit.</td>
        </tr>
<tr>
          <td><code>log_id</code></td>
          <td>string</td>
          <td>no</td>
          <td>The ID to identify request in access and error log.</td>
        </tr>
<tr class="odd">
          <td><code>method</code></td>
          <td>string</td>
          <td>no</td>
          <td>The request method, f.x. <code>GET</code> or <code>POST</code>.</td>
        </tr>
<tr>
          <td><code>notes</code></td>
          <td>table</td>
          <td>yes</td>
          <td>A list of notes that can be passed on from one module to another.</td>
        </tr>
<tr class="odd">
          <td><code>options</code></td>
          <td>string</td>
          <td>no</td>
          <td>The Options directive applied to the current request.</td>
        </tr>
<tr>
          <td><code>path_info</code></td>
          <td>string</td>
          <td>no</td>
          <td>The PATH_INFO extracted from this request.</td>
        </tr>
<tr class="odd">
          <td><code>port</code></td>
          <td>number</td>
          <td>no</td>
          <td>The server port used by the request.</td>
        </tr>
<tr>
          <td><code>protocol</code></td>
          <td>string</td>
          <td>no</td>
          <td>The protocol used, f.x. <code>HTTP/1.1</code></td>
        </tr>
<tr class="odd">
          <td><code>proxyreq</code></td>
          <td>string</td>
          <td>yes</td>
          <td>Denotes whether this is a proxy request or not. This value is generally set in 
            the post_read_request/translate_name phase of a request.</td>
        </tr>
<tr>
          <td><code>range</code></td>
          <td>string</td>
          <td>no</td>
          <td>The contents of the <code>Range:</code> header.</td>
        </tr>
<tr class="odd">
          <td><code>remaining</code></td>
          <td>number</td>
          <td>no</td>
          <td>The number of bytes remaining to be read from the request body.</td>
        </tr>
<tr>
          <td><code>server_built</code></td>
          <td>string</td>
          <td>no</td>
          <td>The time the server executable was built.</td>
        </tr>
<tr class="odd">
          <td><code>server_name</code></td>
          <td>string</td>
          <td>no</td>
          <td>The server name for this request.</td>
        </tr>
<tr>
          <td><code>some_auth_required</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether some authorization is/was required for this request.</td>
        </tr>
<tr class="odd">
          <td><code>subprocess_env</code></td>
          <td>table</td>
          <td>yes</td>
          <td>The environment variables set for this request.</td>
        </tr>
<tr>
          <td><code>started</code></td>
          <td>number</td>
          <td>no</td>
          <td>The time the server was (re)started, in seconds since the epoch (Jan 1st, 1970)</td>
        </tr>
<tr class="odd">
          <td><code>status</code></td>
          <td>number</td>
          <td>yes</td>
          <td>The (current) HTTP return code for this request, f.x. <code>200</code> or <code>404</code>.</td>
        </tr>
<tr>
          <td><code>the_request</code></td>
          <td>string</td>
          <td>no</td>
          <td>The request string as sent by the client, f.x. <code>GET /foo/bar HTTP/1.1</code>.</td>
        </tr>
<tr class="odd">
          <td><code>unparsed_uri</code></td>
          <td>string</td>
          <td>no</td>
          <td>The unparsed URI of the request</td>
        </tr>
<tr>
          <td><code>uri</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The URI after it has been parsed by httpd</td>
        </tr>
<tr class="odd">
          <td><code>user</code></td>
          <td>string</td>
          <td>yes</td>
          <td>If an authentication check has been made, this is set to the name of the authenticated user.</td>
        </tr>
<tr>
          <td><code>useragent_ip</code></td>
          <td>string</td>
          <td>no</td>
          <td>The IP of the user agent making the request</td>
        </tr>
</table>
           </dd>
    </dl>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="functions" id="functions">Built in functions</a></h2>

<p>The request_rec object has (at least) the following methods:</p>

<pre class="prettyprint lang-lua">r:flush()   -- flushes the output buffer.
            -- Returns true if the flush was successful, false otherwise.

while we_have_stuff_to_send do
    r:puts("Bla bla bla\n") -- print something to client
    r:flush() -- flush the buffer (send to client)
    r.usleep(500000) -- fake processing time for 0.5 sec. and repeat
end</pre>


<pre class="prettyprint lang-lua">r:addoutputfilter(name|function) -- add an output filter:

r:addoutputfilter("fooFilter") -- add the fooFilter to the output stream</pre>


<pre class="prettyprint lang-lua">r:sendfile(filename) -- sends an entire file to the client, using sendfile if supported by the current platform:

if use_sendfile_thing then
    r:sendfile("/var/www/large_file.img")
end</pre>


<pre class="prettyprint lang-lua">r:parseargs() -- returns two tables; one standard key/value table for regular GET data, 
              -- and one for multi-value data (fx. foo=1&amp;foo=2&amp;foo=3):

local GET, GETMULTI = r:parseargs()
r:puts("Your name is: " .. GET['name'] or "Unknown")</pre>


<pre class="prettyprint lang-lua">r:parsebody([sizeLimit]) -- parse the request body as a POST and return two lua tables,
                         -- just like r:parseargs().
                         -- An optional number may be passed to specify the maximum number 
                         -- of bytes to parse. Default is 8192 bytes:
                 
local POST, POSTMULTI = r:parsebody(1024*1024)
r:puts("Your name is: " .. POST['name'] or "Unknown")</pre>


<pre class="prettyprint lang-lua">r:puts("hello", " world", "!") -- print to response body, self explanatory</pre>


<pre class="prettyprint lang-lua">r:write("a single string") -- print to response body, self explanatory</pre>


<pre class="prettyprint lang-lua">r:escape_html("&lt;html&gt;test&lt;/html&gt;") -- Escapes HTML code and returns the escaped result</pre>


<pre class="prettyprint lang-lua">r:base64_encode(string) -- Encodes a string using the Base64 encoding standard:

local encoded = r:base64_encode("This is a test") -- returns VGhpcyBpcyBhIHRlc3Q=</pre>


<pre class="prettyprint lang-lua">r:base64_decode(string) -- Decodes a Base64-encoded string:

local decoded = r:base64_decode("VGhpcyBpcyBhIHRlc3Q=") -- returns 'This is a test'</pre>


<pre class="prettyprint lang-lua">r:md5(string) -- Calculates and returns the MD5 digest of a string (binary safe):

local hash = r:md5("This is a test") -- returns ce114e4501d2f4e2dcea3e17b546f339</pre>


<pre class="prettyprint lang-lua">r:sha1(string) -- Calculates and returns the SHA1 digest of a string (binary safe):

local hash = r:sha1("This is a test") -- returns a54d88e06612d820bc3be72877c74f257b561b19</pre>


<pre class="prettyprint lang-lua">r:escape(string) -- URL-Escapes a string:

local url = "http://foo.bar/1 2 3 &amp; 4 + 5"
local escaped = r:escape(url) -- returns 'http%3a%2f%2ffoo.bar%2f1+2+3+%26+4+%2b+5'</pre>


<pre class="prettyprint lang-lua">r:unescape(string) -- Unescapes an URL-escaped string:

local url = "http%3a%2f%2ffoo.bar%2f1+2+3+%26+4+%2b+5"
local unescaped = r:unescape(url) -- returns 'http://foo.bar/1 2 3 &amp; 4 + 5'</pre>


<pre class="prettyprint lang-lua">r:construct_url(string) -- Constructs an URL from an URI

local url = r:construct_url(r.uri)</pre>


<pre class="prettyprint lang-lua">r.mpm_query(number) -- Queries the server for MPM information using ap_mpm_query:

local mpm = r.mpm_query(14)
if mpm == 1 then
    r:puts("This server uses the Event MPM")
end</pre>


<pre class="prettyprint lang-lua">r:expr(string) -- Evaluates an <a href="../expr.html">expr</a> string.

if r:expr("%{HTTP_HOST} =~ /^www/") then
    r:puts("This host name starts with www")
end</pre>


<pre class="prettyprint lang-lua">r:scoreboard_process(a) -- Queries the server for information about the process at position <code>a</code>:

local process = r:scoreboard_process(1)
r:puts("Server 1 has PID " .. process.pid)</pre>


<pre class="prettyprint lang-lua">r:scoreboard_worker(a, b) -- Queries for information about the worker thread, <code>b</code>, in process <code>a</code>:

local thread = r:scoreboard_worker(1, 1)
r:puts("Server 1's thread 1 has thread ID " .. thread.tid .. " and is in " .. thread.status .. " status")</pre>



<pre class="prettyprint lang-lua">r:clock() -- Returns the current time with microsecond precision</pre>


<pre class="prettyprint lang-lua">r:requestbody(filename) -- Reads and returns the request body of a request.
                -- If 'filename' is specified, it instead saves the
                -- contents to that file:
                
local input = r:requestbody()
r:puts("You sent the following request body to me:\n")
r:puts(input)</pre>


<pre class="prettyprint lang-lua">r:add_input_filter(filter_name) -- Adds 'filter_name' as an input filter</pre>


<pre class="prettyprint lang-lua">r.module_info(module_name) -- Queries the server for information about a module

local mod = r.module_info("mod_lua.c")
if mod then
    for k, v in pairs(mod.commands) do
       r:puts( ("%s: %s\n"):format(k,v)) -- print out all directives accepted by this module
    end
end</pre>


<pre class="prettyprint lang-lua">r:loaded_modules() -- Returns a list of modules loaded by httpd:

for k, module in pairs(r:loaded_modules()) do
    r:puts("I have loaded module " .. module .. "\n")
end</pre>


<pre class="prettyprint lang-lua">r:runtime_dir_relative(filename) -- Compute the name of a run-time file (e.g., shared memory "file") 
                         -- relative to the appropriate run-time directory.</pre>


<pre class="prettyprint lang-lua">r:server_info() -- Returns a table containing server information, such as 
                -- the name of the httpd executable file, mpm used etc.</pre>


<pre class="prettyprint lang-lua">r:set_document_root(file_path) -- Sets the document root for the request to file_path</pre>




<pre class="prettyprint lang-lua">r:set_context_info(prefix, docroot) -- Sets the context prefix and context document root for a request</pre>


<pre class="prettyprint lang-lua">r:os_escape_path(file_path) -- Converts an OS path to a URL in an OS dependent way</pre>


<pre class="prettyprint lang-lua">r:escape_logitem(string) -- Escapes a string for logging</pre>


<pre class="prettyprint lang-lua">r.strcmp_match(string, pattern) -- Checks if 'string' matches 'pattern' using strcmp_match (globs).
                        -- fx. whether 'www.example.com' matches '*.example.com':
                        
local match = r.strcmp_match("foobar.com", "foo*.com")
if match then 
    r:puts("foobar.com matches foo*.com")
end</pre>


<pre class="prettyprint lang-lua">r:set_keepalive() -- Sets the keepalive status for a request. Returns true if possible, false otherwise.</pre>


<pre class="prettyprint lang-lua">r:make_etag() -- Constructs and returns the etag for the current request.</pre>


<pre class="prettyprint lang-lua">r:send_interim_response(clear) -- Sends an interim (1xx) response to the client.
                       -- if 'clear' is true, available headers will be sent and cleared.</pre>


<pre class="prettyprint lang-lua">r:custom_response(status_code, string) -- Construct and set a custom response for a given status code.
                               -- This works much like the ErrorDocument directive:
                               
r:custom_response(404, "Baleted!")</pre>


<pre class="prettyprint lang-lua">r.exists_config_define(string) -- Checks whether a configuration definition exists or not:

if r.exists_config_define("FOO") then
    r:puts("httpd was probably run with -DFOO, or it was defined in the configuration")
end</pre>


<pre class="prettyprint lang-lua">r:state_query(string) -- Queries the server for state information</pre>


<pre class="prettyprint lang-lua">r:stat(filename [,wanted]) -- Runs stat() on a file, and returns a table with file information:

local info = r:stat("/var/www/foo.txt")
if info then
    r:puts("This file exists and was last modified at: " .. info.modified)
end</pre>


<pre class="prettyprint lang-lua">r:regex(string, pattern [,flags]) -- Runs a regular expression match on a string, returning captures if matched:

local matches = r:regex("foo bar baz", [[foo (\w+) (\S*)]])
if matches then
    r:puts("The regex matched, and the last word captured ($2) was: " .. matches[2])
end

-- Example ignoring case sensitivity:
local matches = r:regex("FOO bar BAz", [[(foo) bar]], 1)

-- Flags can be a bitwise combination of:
-- 0x01: Ignore case
-- 0x02: Multiline search</pre>


<pre class="prettyprint lang-lua">r.usleep(number_of_microseconds) -- Puts the script to sleep for a given number of microseconds.</pre>


<pre class="prettyprint lang-lua">r:dbacquire(dbType[, dbParams]) -- Acquires a connection to a database and returns a database class.
                        -- See '<a href="#databases">Database connectivity</a>' for details.</pre>


<pre class="prettyprint lang-lua">r:ivm_set("key", value) -- Set an Inter-VM variable to hold a specific value.
                        -- These values persist even though the VM is gone or not being used,
                        -- and so should only be used if MaxConnectionsPerChild is &gt; 0
                        -- Values can be numbers, strings and booleans, and are stored on a 
                        -- per process basis (so they won't do much good with a prefork mpm)
                        
r:ivm_get("key")        -- Fetches a variable set by ivm_set. Returns the contents of the variable
                        -- if it exists or nil if no such variable exists.
                        
-- An example getter/setter that saves a global variable outside the VM:
function handle(r)
    -- First VM to call this will get no value, and will have to create it
    local foo = r:ivm_get("cached_data")
    if not foo then
        foo = do_some_calcs() -- fake some return value
        r:ivm_set("cached_data", foo) -- set it globally
    end
    r:puts("Cached data is: ", foo)
end</pre>


<pre class="prettyprint lang-lua">r:htpassword(string [,algorithm [,cost]]) -- Creates a password hash from a string.
                                          -- algorithm: 0 = APMD5 (default), 1 = SHA, 2 = BCRYPT, 3 = CRYPT.
                                          -- cost: only valid with BCRYPT algorithm (default = 5).</pre>


<pre class="prettyprint lang-lua">r:mkdir(dir [,mode]) -- Creates a directory and sets mode to optional mode parameter.</pre>


<pre class="prettyprint lang-lua">r:mkrdir(dir [,mode]) -- Creates directories recursive and sets mode to optional mode parameter.</pre>


<pre class="prettyprint lang-lua">r:rmdir(dir) -- Removes a directory.</pre>


<pre class="prettyprint lang-lua">r:touch(file [,mtime]) -- Sets the file modification time to current time or to optional mtime msec value.</pre>


<pre class="prettyprint lang-lua">r:get_direntries(dir) -- Returns a table with all directory entries.

function handle(r)
  local dir = r.context_document_root
  for _, f in ipairs(r:get_direntries(dir)) do
    local info = r:stat(dir .. "/" .. f)
    if info then
      local mtime = os.date(fmt, info.mtime / 1000000)
      local ftype = (info.filetype == 2) and "[dir] " or "[file]"
      r:puts( ("%s %s %10i %s\n"):format(ftype, mtime, info.size, f) )
    end
  end
end</pre>


<pre class="prettyprint lang-lua">r.date_parse_rfc(string) -- Parses a date/time string and returns seconds since epoche.</pre>


<pre class="prettyprint lang-lua">r:getcookie(key) -- Gets a HTTP cookie</pre>


<pre class="prettyprint lang-lua">r:setcookie{
  key = [key],
  value = [value],
  expires = [expiry],
  secure = [boolean],
  httponly = [boolean],
  path = [path],
  domain = [domain]
} -- Sets a HTTP cookie, for instance:

r:setcookie{
  key = "cookie1",
  value = "HDHfa9eyffh396rt",
  expires = os.time() + 86400,
  secure = true
}</pre>


<pre class="prettyprint lang-lua">r:wsupgrade() -- Upgrades a connection to WebSockets if possible (and requested):
if r:wsupgrade() then -- if we can upgrade:
    r:wswrite("Welcome to websockets!") -- write something to the client
    r:wsclose()  -- goodbye!
end</pre>


<pre class="prettyprint lang-lua">r:wsread() -- Reads a WebSocket frame from a WebSocket upgraded connection (see above):

local line, isFinal = r:wsread() -- isFinal denotes whether this is the final frame.
                                 -- If it isn't, then more frames can be read
r:wswrite("You wrote: " .. line)</pre>


<pre class="prettyprint lang-lua">r:wswrite(line) -- Writes a frame to a WebSocket client:
r:wswrite("Hello, world!")</pre>


<pre class="prettyprint lang-lua">r:wsclose() -- Closes a WebSocket request and terminates it for httpd:

if r:wsupgrade() then
    r:wswrite("Write something: ")
    local line = r:wsread() or "nothing"
    r:wswrite("You wrote: " .. line);
Show full blame