]> git.ipfire.org Git - thirdparty/cups.git/blobdiff - doc/help/api-filter.html
Move ippeveprinter commands to CUPS_SERVERBIN/command.
[thirdparty/cups.git] / doc / help / api-filter.html
index 4e18d2ef054ec63fe4e8818a8e4ceb536265ed23..eddd06389b42092e49639973acea0f26ab366dfc 100644 (file)
@@ -1,12 +1,15 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<!DOCTYPE html>
 <html>
 <!-- SECTION: Programming -->
-<head>
-       <title>Filter and Backend Programming   </title>
-       <meta name="keywords" content="Programming">
-       <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
-       <meta name="creator" content="Mini-XML v2.7">
-<style type="text/css"><!--
+  <head>
+    <title>Filter and Backend Programming</title>
+    <meta name="keywords" content="Programming">
+    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+    <meta name="creator" content="codedoc v3.1">
+    <meta name="author" content="Unknown">
+    <meta name="copyright" content="Unknown">
+    <meta name="version" content="0.0">
+    <style type="text/css"><!--
 BODY {
   font-family: lucida grande, geneva, helvetica, arial, sans-serif;
 }
@@ -15,6 +18,11 @@ H1, H2, H3, H4, H5, H6, P, TD, TH {
   font-family: lucida grande, geneva, helvetica, arial, sans-serif;
 }
 
+H1 { font-size: 2em; }
+H2 { font-size: 1.75em; }
+H3 { font-size: 1.5em; }
+H4 { font-size: 1.25em; }
+
 KBD {
   font-family: monaco, courier, monospace;
   font-weight: bold;
@@ -24,9 +32,19 @@ PRE {
   font-family: monaco, courier, monospace;
 }
 
-PRE.command {
-  border: dotted thin #7f7f7f;
-  margin-left: 36pt;
+BLOCKQUOTE {
+  border-left: solid 2px #777;
+  margin: 1em 0;
+  padding: 10px;
+}
+
+BLOCKQUOTE OL LI {
+  margin-left: -1em;
+}
+
+PRE.command, PRE.example {
+  background: #eee;
+  margin: 0 36pt;
   padding: 10px;
 }
 
@@ -38,12 +56,17 @@ P.example {
   font-style: italic;
   margin-left: 36pt;
 }
-  
-PRE.example {
-  background: #eeeeee;
-  border: dotted thin #999999;
-  margin-left: 36pt;
-  padding: 10pt;
+
+DL.man DD {
+  margin-left: 5em;
+}
+
+DL.man DT {
+  margin-left: 0;
+}
+
+PRE.man {
+  margin: 0;
 }
 
 PRE.command EM, PRE.example EM {
@@ -60,12 +83,6 @@ P.formula {
   margin-left: 36pt;
 }
 
-BLOCKQUOTE {
-  background: #eeeeee;
-  border: solid thin #999999;
-  padding: 10pt;
-}
-
 A IMG {
   border: none;
 }
@@ -77,7 +94,7 @@ A:link:hover IMG {
 }
 
 A:link, A:visited {
-  font-weight: normal;
+  font-weight: inherit;
   text-decoration: none;
 }
 
@@ -121,7 +138,7 @@ DIV.table CAPTION {
 
 DIV.table TABLE TD {
   border: solid thin #cccccc;
-  padding-top: 5pt;
+  padding: 5pt 10pt 0;
 }
 
 DIV.table TABLE TH {
@@ -269,26 +286,126 @@ DIV.summary TABLE THEAD TH {
 
 /* API documentation styles... */
 div.body h1 {
+  font-size: 250%;
+  font-weight: bold;
   margin: 0;
 }
 div.body h2 {
+  font-size: 250%;
   margin-top: 1.5em;
 }
-div.body h3, div.body h4, div.body h5 {
+div.body h3 {
+  font-size: 150%;
   margin-bottom: 0.5em;
   margin-top: 1.5em;
 }
-.class, .enumeration, .function, .struct, .typedef, .union {
-  border-bottom: solid thin #999999;
-  margin-bottom: 0;
-  margin-top: 2em;
+div.body h4 {
+  font-size: 110%;
+  margin-bottom: 0.5em;
+  margin-top: 1.5em;
+}
+div.body h5 {
+  font-size: 100%;
+  margin-bottom: 0.5em;
+  margin-top: 1.5em;
+}
+div.contents {
+  background: #e8e8e8;
+  border: solid thin black;
+  padding: 10px;
+}
+div.contents h1 {
+  font-size: 110%;
+}
+div.contents h2 {
+  font-size: 100%;
+}
+div.contents ul.contents {
+  font-size: 80%;
+}
+.class {
+  border-bottom: solid 2px gray;
+}
+.constants {
 }
 .description {
   margin-top: 0.5em;
 }
-code, p.code, pre, ul.code li {
-  font-family: monaco, courier, monospace;
-  font-size: 90%;
+.discussion {
+}
+.enumeration {
+  border-bottom: solid 2px gray;
+}
+.function {
+  border-bottom: solid 2px gray;
+  margin-bottom: 0;
+}
+.members {
+}
+.method {
+}
+.parameters {
+}
+.returnvalue {
+}
+.struct {
+  border-bottom: solid 2px gray;
+}
+.typedef {
+  border-bottom: solid 2px gray;
+}
+.union {
+  border-bottom: solid 2px gray;
+}
+.variable {
+}
+h1, h2, h3, h4, h5, h6 {
+  page-break-inside: avoid;
+}
+blockquote {
+  border: solid thin gray;
+  box-shadow: 3px 3px 5px rgba(0,0,0,0.5);
+  padding: 10px 10px 0px;
+  page-break-inside: avoid;
+}
+p code, li code, p.code, pre, ul.code li {
+  background: rgba(127,127,127,0.1);
+  border: thin dotted gray;
+  font-family: monospace;
+  hyphens: manual;
+  -webkit-hyphens: manual;
+  page-break-inside: avoid;
+}
+p.code, pre, ul.code li {
+  padding: 10px;
+}
+p code, li code {
+  padding: 2px 5px;
+}
+a:link, a:visited {
+  text-decoration: none;
+}
+span.info {
+  background: black;
+  border: solid thin black;
+  color: white;
+  font-size: 80%;
+  font-style: italic;
+  font-weight: bold;
+  white-space: nowrap;
+}
+h2 span.info, h3 span.info, h4 span.info {
+  border-radius: 10px;
+  float: right;
+  font-size: 80%;
+  padding: 3px 6px;
+}
+h2.title span.info, h3.title span.info, h4.title span.info {
+  border-bottom-left-radius: 0px;
+  border-bottom-right-radius: 0px;
+}
+h2.title span.info {
+  padding: 4px 6px;
 }
 ul.code, ul.contents, ul.subcontents {
   list-style-type: none;
@@ -304,54 +421,42 @@ ul.contents > li {
 ul.contents li ul.code, ul.contents li ul.subcontents {
   padding-left: 2em;
 }
-div.body dl {
-  margin-left: 0;
-  margin-top: 0;
-}
-div.body dt {
-  font-style: italic;
-  margin-left: 0;
-  margin-top: 0;
-}
-div.body dd {
-  margin-bottom: 0.5em;
-}
-
-/* This is just for the HTML files generated with the framedhelp target */
-div.contents {
-  background: #e8e8e8;
-  border: solid thin black;
-  padding: 10px;
+table.list {
+  border-collapse: collapse;
+  width: 100%;
+}
+table.list tr:nth-child(even) {
+  background: rgba(127,127,127,0.1);]n}
+table.list th {
+  border-right: 2px solid gray;
+  font-family: monospace;
+  padding: 5px 10px 5px 2px;
+  text-align: right;
+  vertical-align: top;
 }
-div.contents h1 {
-  font-size: 110%;
+table.list td {
+  padding: 5px 2px 5px 10px;
+  text-align: left;
+  vertical-align: top;
 }
-div.contents h2 {
-  font-size: 100%;
+h1.title {
 }
-div.contents ul.contents {
-  font-size: 80%;
+h2.title {
+  border-bottom: solid 2px black;
 }
-div.contents ul.subcontents li {
-  margin-left: 1em;
-  text-indent: -1em;
+h3.title {
+  border-bottom: solid 2px black;
 }
 --></style>
-</head>
-<body>
-<div class='body'>
+  </head>
+  <body>
 <!--
-  "$Id$"
-
   Filter and backend programming header for CUPS.
 
-  Copyright 2008-2011 by Apple Inc.
+  Copyright © 2008-2016 by Apple Inc.
 
-  These coded instructions, statements, and computer programs are the
-  property of Apple Inc. and are protected by Federal copyright
-  law.  Distribution and use rights are outlined in the file "LICENSE.txt"
-  which should have been included with this file.  If this file is
-  file is missing or damaged, see the license at "http://www.cups.org/".
+  Licensed under Apache License v2.0.  See the file "LICENSE" for more
+  information.
 -->
 
 <h1 class='title'>Filter and Backend Programming</h1>
@@ -361,6 +466,7 @@ div.contents ul.subcontents li {
 <tr>
        <th>Headers</th>
        <th>cups/backend.h<br>
+       cups/ppd.h<br>
        cups/sidechannel.h</th>
 </tr>
 </thead>
@@ -381,63 +487,62 @@ div.contents ul.subcontents li {
 </tr>
 </tbody>
 </table></div>
-<h2 class="title">Contents</h2>
-<ul class="contents">
-<li><a href="#OVERVIEW">Overview</a><ul class="subcontents">
-       <li><a href="#SECURITY">Security Considerations</a></li>
-       <li><a href="#SIGNALS">Canceled Jobs and Signal Handling</a></li>
-       <li><a href="#PERMISSIONS">File Permissions</a></li>
-       <li><a href="#TEMPFILES">Temporary Files</a></li>
-       <li><a href="#COPIES">Copy Generation</a></li>
-       <li><a href="#EXITCODES">Exit Codes</a></li>
-       <li><a href="#ENVIRONMENT">Environment Variables</a></li>
-       <li><a href="#MESSAGES">Communicating with the Scheduler</a></li>
-       <li><a href="#COMMUNICATING_BACKEND">Communicating with the Backend</a></li>
-       <li><a href="#COMMUNICATING_FILTER">Communicating with Filters</a></li>
-       <li><a href="#SNMP">Doing SNMP Queries with Network Printers</a></li>
-</ul></li>
-<li><a href="#FUNCTIONS">Functions</a><ul class="code">
-       <li><a href="#cupsBackChannelRead" title="Read data from the backchannel.">cupsBackChannelRead</a></li>
-       <li><a href="#cupsBackChannelWrite" title="Write data to the backchannel.">cupsBackChannelWrite</a></li>
-       <li><a href="#cupsBackendDeviceURI" title="Get the device URI for a backend.">cupsBackendDeviceURI</a></li>
-       <li><a href="#cupsBackendReport" title="Write a device line from a backend.">cupsBackendReport</a></li>
-       <li><a href="#cupsSideChannelDoRequest" title="Send a side-channel command to a backend and wait for a response.">cupsSideChannelDoRequest</a></li>
-       <li><a href="#cupsSideChannelRead" title="Read a side-channel message.">cupsSideChannelRead</a></li>
-       <li><a href="#cupsSideChannelSNMPGet" title="Query a SNMP OID's value.">cupsSideChannelSNMPGet</a></li>
-       <li><a href="#cupsSideChannelSNMPWalk" title="Query multiple SNMP OID values.">cupsSideChannelSNMPWalk</a></li>
-       <li><a href="#cupsSideChannelWrite" title="Write a side-channel message.">cupsSideChannelWrite</a></li>
-</ul></li>
-<li><a href="#TYPES">Data Types</a><ul class="code">
-       <li><a href="#cups_backend_t" title="Backend exit codes">cups_backend_t</a></li>
-       <li><a href="#cups_sc_bidi_t" title="Bidirectional capabilities">cups_sc_bidi_t</a></li>
-       <li><a href="#cups_sc_command_t" title="Request command codes">cups_sc_command_t</a></li>
-       <li><a href="#cups_sc_connected_t" title="Connectivity values">cups_sc_connected_t</a></li>
-       <li><a href="#cups_sc_state_t" title="Printer state bits">cups_sc_state_t</a></li>
-       <li><a href="#cups_sc_status_t" title="Response status codes">cups_sc_status_t</a></li>
-       <li><a href="#cups_sc_walk_func_t" title="SNMP walk callback">cups_sc_walk_func_t</a></li>
-</ul></li>
-<li><a href="#ENUMERATIONS">Constants</a><ul class="code">
-       <li><a href="#cups_backend_e" title="Backend exit codes">cups_backend_e</a></li>
-       <li><a href="#cups_sc_bidi_e" title="Bidirectional capability values">cups_sc_bidi_e</a></li>
-       <li><a href="#cups_sc_command_e" title="Request command codes">cups_sc_command_e</a></li>
-       <li><a href="#cups_sc_connected_e" title="Connectivity values">cups_sc_connected_e</a></li>
-       <li><a href="#cups_sc_state_e" title="Printer state bits">cups_sc_state_e</a></li>
-       <li><a href="#cups_sc_status_e" title="Response status codes">cups_sc_status_e</a></li>
-</ul></li>
-</ul>
+    <div class="contents">
+      <h2 class="title">Contents</h2>
+      <ul class="contents">
+        <li><a href="#OVERVIEW">Overview</a><ul class="subcontents">
+          <li><a href="#SECURITY">Security Considerations</a></li>
+          <li><a href="#SIGNALS">Canceled Jobs and Signal Handling</a></li>
+          <li><a href="#PERMISSIONS">File Permissions</a></li>
+          <li><a href="#TEMPFILES">Temporary Files</a></li>
+          <li><a href="#COPIES">Copy Generation</a></li>
+          <li><a href="#EXITCODES">Exit Codes</a></li>
+          <li><a href="#ENVIRONMENT">Environment Variables</a></li>
+          <li><a href="#MESSAGES">Communicating with the Scheduler</a></li>
+          <li><a href="#COMMUNICATING_BACKEND">Communicating with the Backend</a></li>
+          <li><a href="#COMMUNICATING_FILTER">Communicating with Filters</a></li>
+          <li><a href="#SNMP">Doing SNMP Queries with Network Printers</a></li>
+        </ul></li>
+        <li><a href="#SANDBOXING">Sandboxing on macOS</a></li>
+        <li><a href="#FUNCTIONS">Functions</a><ul class="subcontents">
+          <li><a href="#cupsBackChannelRead">cupsBackChannelRead</a></li>
+          <li><a href="#cupsBackChannelWrite">cupsBackChannelWrite</a></li>
+          <li><a href="#cupsBackendDeviceURI">cupsBackendDeviceURI</a></li>
+          <li><a href="#cupsBackendReport">cupsBackendReport</a></li>
+          <li><a href="#cupsSideChannelDoRequest">cupsSideChannelDoRequest</a></li>
+          <li><a href="#cupsSideChannelRead">cupsSideChannelRead</a></li>
+          <li><a href="#cupsSideChannelSNMPGet">cupsSideChannelSNMPGet</a></li>
+          <li><a href="#cupsSideChannelSNMPWalk">cupsSideChannelSNMPWalk</a></li>
+          <li><a href="#cupsSideChannelWrite">cupsSideChannelWrite</a></li>
+        </ul></li>
+        <li><a href="#TYPES">Data Types</a><ul class="subcontents">
+          <li><a href="#cups_backend_t">cups_backend_t</a></li>
+          <li><a href="#cups_sc_bidi_t">cups_sc_bidi_t</a></li>
+          <li><a href="#cups_sc_command_t">cups_sc_command_t</a></li>
+          <li><a href="#cups_sc_connected_t">cups_sc_connected_t</a></li>
+          <li><a href="#cups_sc_state_t">cups_sc_state_t</a></li>
+          <li><a href="#cups_sc_status_t">cups_sc_status_t</a></li>
+          <li><a href="#cups_sc_walk_func_t">cups_sc_walk_func_t</a></li>
+        </ul></li>
+        <li><a href="#ENUMERATIONS">Enumerations</a><ul class="subcontents">
+          <li><a href="#cups_backend_e">cups_backend_e</a></li>
+          <li><a href="#cups_sc_bidi_e">cups_sc_bidi_e</a></li>
+          <li><a href="#cups_sc_command_e">cups_sc_command_e</a></li>
+          <li><a href="#cups_sc_connected_e">cups_sc_connected_e</a></li>
+          <li><a href="#cups_sc_state_e">cups_sc_state_e</a></li>
+          <li><a href="#cups_sc_status_e">cups_sc_status_e</a></li>
+        </ul></li>
+      </ul>
+    </div>
+    <div class="body">
 <!--
-  "$Id$"
-
   Filter and backend programming introduction for CUPS.
 
-  Copyright 2007-2011 by Apple Inc.
-  Copyright 1997-2006 by Easy Software Products, all rights reserved.
+  Copyright © 2007-2016 by Apple Inc.
+  Copyright © 1997-2006 by Easy Software Products, all rights reserved.
 
-  These coded instructions, statements, and computer programs are the
-  property of Apple Inc. and are protected by Federal copyright
-  law.  Distribution and use rights are outlined in the file "LICENSE.txt"
-  which should have been included with this file.  If this file is
-  file is missing or damaged, see the license at "http://www.cups.org/".
+  Licensed under Apache License v2.0.  See the file "LICENSE" for more
+  information.
 -->
 
 <h2 class='title'><a name="OVERVIEW">Overview</a></h2>
@@ -508,7 +613,7 @@ directory to write to.</p>
 
 <p>In addition, some operating systems provide additional security mechanisms
 that further limit file system access, even for backends running as root. On
-Mac OS X, for example, no backend may write to a user's home directory.</p>
+macOS, for example, no backend may write to a user's home directory. See the <a href="#SANDBOXING">Sandboxing on macOS</a> section for more information.</p>
 </blockquote>
 
 <h3><a name="SIGNALS">Canceled Jobs and Signal Handling</a></h3>
@@ -523,7 +628,7 @@ being printed.</p>
 <p>Filters and backends may also receive <code>SIGPIPE</code> when an upstream or downstream filter/backend exits with a non-zero status. Developers should generally ignore <code>SIGPIPE</code> at the beginning of <code>main()</code> with the following function call:</p>
 
 <pre class="example">
-#include &lt;signal.h&gt;>
+#include &lt;signal.h&gt;
 
 ...
 
@@ -580,7 +685,7 @@ when running print filters and backends:</p>
 
        <dt>APPLE_LANGUAGE</dt>
        <dd>The Apple language identifier associated with the job
-       (Mac OS X only).</dd>
+       (macOS only).</dd>
 
        <dt>CHARSET</dt>
        <dd>The job character set, typically "utf-8".</dd>
@@ -664,7 +769,7 @@ prefix strings:</p>
        <code>marker-types</code>, <code>printer-alert</code>, and
        <code>printer-alert-description</code> printer attributes. Standard
        <code>marker-types</code> values are listed in <a href='#TABLE1'>Table
-       1</a>.</dd>
+       1</a>. String values need special handling - see <a href="#ATTR_STRINGS">Reporting Attribute String Values</a> below.</dd>
 
        <dt>CRIT: message</dt>
        <dd>Sets the printer-state-message attribute and adds the specified
@@ -714,7 +819,7 @@ prefix strings:</p>
        <dd>Sets or clears printer-state-reason keywords for the current queue.
        Typically this is used to indicate persistent media, ink, toner, and
        configuration conditions or errors on a printer.
-       <a href='#TABLE2'>Table 2</a> lists the standard state keywords -
+       <a href='#TABLE2'>Table 2</a> lists some of the standard "printer-state-reasons" keywords from the <a href="http://www.iana.org/assignments/ipp-registrations/ipp-registrations.xhtml#ipp-registrations-4">IANA IPP Registry</a> -
        use vendor-prefixed ("com.example.foo") keywords for custom states. See
        <a href="#MANAGING_STATE">Managing Printer State in a Filter</a> for more
        information.
@@ -747,11 +852,11 @@ the "DEBUG:" prefix string.</p>
        <td>Fuser unit</td>
 </tr>
 <tr>
-       <td>fuserCleaningPad</td>
+       <td>fuser-cleaning-pad</td>
        <td>Fuser cleaning pad</td>
 </tr>
 <tr>
-       <td>fuserOil</td>
+       <td>fuser-oil</td>
        <td>Fuser oil</td>
 </tr>
 <tr>
@@ -763,7 +868,7 @@ the "DEBUG:" prefix string.</p>
        <td>Photo conductor</td>
 </tr>
 <tr>
-       <td>solidWax</td>
+       <td>solid-wax</td>
        <td>Wax supply</td>
 </tr>
 <tr>
@@ -775,19 +880,19 @@ the "DEBUG:" prefix string.</p>
        <td>Toner supply</td>
 </tr>
 <tr>
-       <td>transferUnit</td>
+       <td>transfer-unit</td>
        <td>Transfer unit</td>
 </tr>
 <tr>
-       <td>wasteInk</td>
+       <td>waste-ink</td>
        <td>Waste ink tank</td>
 </tr>
 <tr>
-       <td>wasteToner</td>
+       <td>waste-toner</td>
        <td>Waste toner tank</td>
 </tr>
 <tr>
-       <td>wasteWax</td>
+       <td>waste-wax</td>
        <td>Waste wax tank</td>
 </tr>
 </tbody>
@@ -867,6 +972,95 @@ the "DEBUG:" prefix string.</p>
 </tbody>
 </table></div>
 
+
+<h4><a name="ATTR_STRINGS">Reporting Attribute String Values</a></h4>
+
+<p>When reporting string values using "ATTR:" messages, a filter or backend must take special care to appropriately quote those values. The scheduler uses the CUPS option parsing code for attributes, so the general syntax is:</p>
+
+<pre class="example">
+name=simple
+name=simple,simple,...
+name='complex value'
+name="complex value"
+name='"complex value"','"complex value"',...
+</pre>
+
+<p>Simple values are strings that do not contain spaces, quotes, backslashes, or the comma and can be placed verbatim in the "ATTR:" message, for example:</p>
+
+<pre class="example">
+int levels[4] = { 40, 50, 60, 70 }; /* CMYK */
+
+fputs("ATTR: marker-colors=#00FFFF,#FF00FF,#FFFF00,#000000\n", stderr);
+fputs("ATTR: marker-high-levels=100,100,100,100\n", stderr);
+fprintf(stderr, "ATTR: marker-levels=%d,%d,%d,%d\n", levels[0], levels[1],
+        levels[2], levels[3], levels[4]);
+fputs("ATTR: marker-low-levels=5,5,5,5\n", stderr);
+fputs("ATTR: marker-types=toner,toner,toner,toner\n", stderr);
+</pre>
+
+<p>Complex values that contains spaces, quotes, backslashes, or the comma must be quoted. For a single value a single set of quotes is sufficient:</p>
+
+<pre class="example">
+fputs("ATTR: marker-message='Levels shown are approximate.'\n", stderr);
+</pre>
+
+<p>When multiple values are reported, each value must be enclosed by a set of single and double quotes:</p>
+
+<pre class="example">
+fputs("ATTR: marker-names='\"Cyan Toner\"','\"Magenta Toner\"',"
+      "'\"Yellow Toner\"','\"Black Toner\"'\n", stderr);
+</pre>
+
+<p>The IPP backend includes a <var>quote_string</var> function that may be used to properly quote a complex value in an "ATTR:" message:</p>
+
+<pre class="example">
+static const char *                     /* O - Quoted string */
+quote_string(const char *s,             /* I - String */
+             char       *q,             /* I - Quoted string buffer */
+             size_t     qsize)          /* I - Size of quoted string buffer */
+{
+  char  *qptr,                          /* Pointer into string buffer */
+        *qend;                          /* End of string buffer */
+
+
+  qptr = q;
+  qend = q + qsize - 5;
+
+  if (qend &lt; q)
+  {
+    *q = '\0';
+    return (q);
+  }
+
+  *qptr++ = '\'';
+  *qptr++ = '\"';
+
+  while (*s && qptr &lt; qend)
+  {
+    if (*s == '\\' || *s == '\"' || *s == '\'')
+    {
+      if (qptr &lt; (qend - 4))
+      {
+        *qptr++ = '\\';
+        *qptr++ = '\\';
+        *qptr++ = '\\';
+      }
+      else
+        break;
+    }
+
+    *qptr++ = *s++;
+  }
+
+  *qptr++ = '\"';
+  *qptr++ = '\'';
+  *qptr   = '\0';
+
+  return (q);
+}
+</pre>
+
+
 <h4><a name="MANAGING_STATE">Managing Printer State in a Filter</a></h4>
 
 <p>Filters are responsible for managing the state keywords they set using
@@ -901,7 +1095,7 @@ sub-state and not an issue that applies when a job is not printing.</p>
 <blockquote><b>Note:</b>
 
 <p>"STATE:" messages often provide visible alerts to the user. For example,
-on Mac OS X setting a printer-state-reason value with an "-error" or
+on macOS setting a printer-state-reason value with an "-error" or
 "-warning" suffix will cause the printer's dock item to bounce if the
 corresponding reason is localized with a cupsIPPReason keyword in the
 printer's PPD file.</p>
@@ -915,7 +1109,7 @@ from localizing the vendor-prefixed keyword in the PPD file - otherwise both
 the generic and vendor-specific keyword will be shown in the user
 interface.</p>
 
-</blockquote></dd>
+</blockquote>
 
 <h4><a name="REPORTING_SUPPLIES">Reporting Supply Levels</a></h4>
 
@@ -1040,7 +1234,7 @@ datalen = sizeof(data) - 1;
 status = <a href="#cupsSideChannelDoRequest">cupsSideChannelDoRequest</a>(CUPS_SC_CMD_GET_DEVICE_ID, data, &amp;datalen, 1.0);
 
 /* Use the returned value if OK was returned and the length is non-zero */
-if (status == CUPS_SC_STATUS_OK && datalen > 0)
+if (status == CUPS_SC_STATUS_OK &amp;&amp; datalen > 0)
   data[datalen] = '\0';
 else
   data[0] = '\0';
@@ -1190,134 +1384,137 @@ void *my_data;
 
 <a href="#cupsSideChannelSNMPWalk">cupsSNMPSideChannelWalk</a>(".1.3.6.1.2.1.43", 5.0, my_callback, my_data);
 </pre>
-<h2 class="title"><a name="FUNCTIONS">Functions</a></h2>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.2/Mac OS X 10.5&nbsp;</span><a name="cupsBackChannelRead">cupsBackChannelRead</a></h3>
-<p class="description">Read data from the backchannel.</p>
+
+<h2><a name="SANDBOXING">Sandboxing on macOS</a></h2>
+
+<p>Starting with macOS 10.6, filters and backends are run inside a security "sandbox" which further limits (beyond the normal UNIX user/group permissions) what a filter or backend can do. This helps to both secure the printing system from malicious software and enforce the functional separation of components in the CUPS filter chain. What follows is a list of actions that are explicitly allowed for all filters and backends:</p>
+
+<ol>
+
+       <li>Reading of files: pursuant to normal UNIX file permissions, filters and backends can read files for the current job from the <var>/private/var/spool/cups</var> directory and other files on mounted filesystems <em>except</em> for user home directories under <var>/Users</var>.</li>
+
+       <li>Writing of files: pursuant to normal UNIX file permissions, filters and backends can read/write files to the cache directory specified by the <code>CUPS_CACHEDIR</code> environment variable, to the state directory specified by the <code>CUPS_STATEDIR</code> environment variable, to the temporary directory specified by the <code>TMPDIR</code> environment variable, and under the <var>/private/var/db</var>, <var>/private/var/folders</var>, <var>/private/var/lib</var>, <var>/private/var/mysql</var>, <var>/private/var/run</var>, <var>/private/var/spool</var> (except <var>/private/var/spool/cups</var>), <var>/Library/Application&nbsp;Support</var>, <var>/Library/Caches</var>, <var>/Library/Logs</var>, <var>/Library/Preferences</var>, <var>/Library/WebServer</var>, and <var>/Users/Shared</var> directories.</li>
+
+       <li>Execution of programs: pursuant to normal UNIX file permissions, filters and backends can execute any program not located under the <var>/Users</var> directory. Child processes inherit the sandbox and are subject to the same restrictions as the parent.</li>
+
+       <li>Bluetooth and USB: backends can access Bluetooth and USB printers through IOKit. <em>Filters cannot access Bluetooth and USB printers directly.</em></li>
+
+       <li>Network: filters and backends can access UNIX domain sockets under the <var>/private/tmp</var>, <var>/private/var/run</var>, and <var>/private/var/tmp</var> directories. Backends can also create IPv4 and IPv6 TCP (outgoing) and UDP (incoming and outgoing) socket, and bind to local source ports. <em>Filters cannot directly create IPv4 and IPv6 TCP or UDP sockets.</em></li>
+
+       <li>Notifications: filters and backends can send notifications via the Darwin <code>notify_post()</code> API.</li>
+
+</ol>
+
+<blockquote><b>Note:</b>
+
+<p>The sandbox profile used in CUPS still allows some actions that are not listed above - these privileges will be removed over time until the profile matches the list above.</p>
+</blockquote>
+      <h2 class="title"><a id="FUNCTIONS">Functions</a></h2>
+<h3 class="function"><span class="info">&#160;CUPS 1.2/macOS 10.5&#160;</span><a id="cupsBackChannelRead">cupsBackChannelRead</a></h3>
+        <p class="description">Read data from the backchannel.</p>
 <p class="code">
-ssize_t cupsBackChannelRead (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;char *buffer,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;size_t bytes,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+ssize_t cupsBackChannelRead(char *buffer, size_t bytes, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>buffer</dt>
-<dd class="description">Buffer to read into</dd>
-<dt>bytes</dt>
-<dd class="description">Bytes to read</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds, typically 0.0 to poll</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>buffer</th>
+        <td class="description">Buffer to read into</td></tr>
+<tr><th>bytes</th>
+        <td class="description">Bytes to read</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds, typically 0.0 to poll</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Bytes read or -1 on error</p>
+        <p class="description">Bytes read or -1 on error</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">Reads up to &quot;bytes&quot; bytes from the backchannel/backend. The &quot;timeout&quot;
+        <p class="discussion">Reads up to &quot;bytes&quot; bytes from the backchannel/backend. The &quot;timeout&quot;
 parameter controls how many seconds to wait for the data - use 0.0 to
 return immediately if there is no data, -1.0 to wait for data indefinitely.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.2/Mac OS X 10.5&nbsp;</span><a name="cupsBackChannelWrite">cupsBackChannelWrite</a></h3>
-<p class="description">Write data to the backchannel.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.2/macOS 10.5&#160;</span><a id="cupsBackChannelWrite">cupsBackChannelWrite</a></h3>
+        <p class="description">Write data to the backchannel.</p>
 <p class="code">
-ssize_t cupsBackChannelWrite (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *buffer,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;size_t bytes,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+ssize_t cupsBackChannelWrite(const char *buffer, size_t bytes, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>buffer</dt>
-<dd class="description">Buffer to write</dd>
-<dt>bytes</dt>
-<dd class="description">Bytes to write</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds, typically 1.0</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>buffer</th>
+        <td class="description">Buffer to write</td></tr>
+<tr><th>bytes</th>
+        <td class="description">Bytes to write</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds, typically 1.0</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Bytes written or -1 on error</p>
+        <p class="description">Bytes written or -1 on error</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">Writes &quot;bytes&quot; bytes to the backchannel/filter. The &quot;timeout&quot; parameter
+        <p class="discussion">Writes &quot;bytes&quot; bytes to the backchannel/filter. The &quot;timeout&quot; parameter
 controls how many seconds to wait for the data to be written - use
 0.0 to return immediately if the data cannot be written, -1.0 to wait
 indefinitely.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.2/Mac OS X 10.5&nbsp;</span><a name="cupsBackendDeviceURI">cupsBackendDeviceURI</a></h3>
-<p class="description">Get the device URI for a backend.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.2/macOS 10.5&#160;</span><a id="cupsBackendDeviceURI">cupsBackendDeviceURI</a></h3>
+        <p class="description">Get the device URI for a backend.</p>
 <p class="code">
-const char *cupsBackendDeviceURI (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;char **argv<br>
-);</p>
+const char *cupsBackendDeviceURI(char **argv);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>argv</dt>
-<dd class="description">Command-line arguments</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>argv</th>
+        <td class="description">Command-line arguments</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Device URI or <code>NULL</code></p>
+        <p class="description">Device URI or <code>NULL</code></p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">The &quot;argv&quot; argument is the argv argument passed to main(). This
+        <p class="discussion">The &quot;argv&quot; argument is the argv argument passed to main(). This
 function returns the device URI passed in the DEVICE_URI environment
 variable or the device URI passed in argv[0], whichever is found
 first.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.4/Mac OS X 10.6&nbsp;</span><a name="cupsBackendReport">cupsBackendReport</a></h3>
-<p class="description">Write a device line from a backend.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.4/macOS 10.6&#160;</span><a id="cupsBackendReport">cupsBackendReport</a></h3>
+        <p class="description">Write a device line from a backend.</p>
 <p class="code">
-void cupsBackendReport (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_scheme,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_uri,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_make_and_model,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_info,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_id,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *device_location<br>
-);</p>
+void cupsBackendReport(const char *device_scheme, const char *device_uri, const char *device_make_and_model, const char *device_info, const char *device_id, const char *device_location);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>device_scheme</dt>
-<dd class="description">device-scheme string</dd>
-<dt>device_uri</dt>
-<dd class="description">device-uri string</dd>
-<dt>device_make_and_model</dt>
-<dd class="description">device-make-and-model string or <code>NULL</code></dd>
-<dt>device_info</dt>
-<dd class="description">device-info string or <code>NULL</code></dd>
-<dt>device_id</dt>
-<dd class="description">device-id string or <code>NULL</code></dd>
-<dt>device_location</dt>
-<dd class="description">device-location string or <code>NULL</code></dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>device_scheme</th>
+        <td class="description">device-scheme string</td></tr>
+<tr><th>device_uri</th>
+        <td class="description">device-uri string</td></tr>
+<tr><th>device_make_and_model</th>
+        <td class="description">device-make-and-model string or <code>NULL</code></td></tr>
+<tr><th>device_info</th>
+        <td class="description">device-info string or <code>NULL</code></td></tr>
+<tr><th>device_id</th>
+        <td class="description">device-id string or <code>NULL</code></td></tr>
+<tr><th>device_location</th>
+        <td class="description">device-location string or <code>NULL</code></td></tr>
+</tbody></table>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function writes a single device line to stdout for a backend.
+        <p class="discussion">This function writes a single device line to stdout for a backend.
 It handles quoting of special characters in the device-make-and-model,
 device-info, device-id, and device-location strings.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.3/Mac OS X 10.5&nbsp;</span><a name="cupsSideChannelDoRequest">cupsSideChannelDoRequest</a></h3>
-<p class="description">Send a side-channel command to a backend and wait for a response.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.3/macOS 10.5&#160;</span><a id="cupsSideChannelDoRequest">cupsSideChannelDoRequest</a></h3>
+        <p class="description">Send a side-channel command to a backend and wait for a response.</p>
 <p class="code">
-<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelDoRequest (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_command_t">cups_sc_command_t</a> command,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;char *data,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;int *datalen,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelDoRequest(<a href="#cups_sc_command_t">cups_sc_command_t</a> command, char *data, int *datalen, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>command</dt>
-<dd class="description">Command to send</dd>
-<dt>data</dt>
-<dd class="description">Response data buffer pointer</dd>
-<dt>datalen</dt>
-<dd class="description">Size of data buffer on entry, number of bytes in buffer on return</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>command</th>
+        <td class="description">Command to send</td></tr>
+<tr><th>data</th>
+        <td class="description">Response data buffer pointer</td></tr>
+<tr><th>datalen</th>
+        <td class="description">Size of data buffer on entry, number of bytes in buffer on return</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Status of command</p>
+        <p class="description">Status of command</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function is normally only called by filters, drivers, or port
+        <p class="discussion">This function is normally only called by filters, drivers, or port
 monitors in order to communicate with the backend used by the current
 printer.  Programs must be prepared to handle timeout or &quot;not
 implemented&quot; status codes, which indicate that the backend or device
@@ -1328,33 +1525,27 @@ pointed to by the &quot;data&quot; parameter.  cupsSideChannelDoRequest() will
 update the value to contain the number of data bytes in the buffer.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.3/Mac OS X 10.5&nbsp;</span><a name="cupsSideChannelRead">cupsSideChannelRead</a></h3>
-<p class="description">Read a side-channel message.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.3/macOS 10.5&#160;</span><a id="cupsSideChannelRead">cupsSideChannelRead</a></h3>
+        <p class="description">Read a side-channel message.</p>
 <p class="code">
-int cupsSideChannelRead (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_command_t">cups_sc_command_t</a> *command,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_status_t">cups_sc_status_t</a> *status,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;char *data,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;int *datalen,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+int cupsSideChannelRead(<a href="#cups_sc_command_t">cups_sc_command_t</a> *command, <a href="#cups_sc_status_t">cups_sc_status_t</a> *status, char *data, int *datalen, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>command</dt>
-<dd class="description">Command code</dd>
-<dt>status</dt>
-<dd class="description">Status code</dd>
-<dt>data</dt>
-<dd class="description">Data buffer pointer</dd>
-<dt>datalen</dt>
-<dd class="description">Size of data buffer on entry, number of bytes in buffer on return</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>command</th>
+        <td class="description">Command code</td></tr>
+<tr><th>status</th>
+        <td class="description">Status code</td></tr>
+<tr><th>data</th>
+        <td class="description">Data buffer pointer</td></tr>
+<tr><th>datalen</th>
+        <td class="description">Size of data buffer on entry, number of bytes in buffer on return</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">0 on success, -1 on error</p>
+        <p class="description">0 on success, -1 on error</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function is normally only called by backend programs to read
+        <p class="discussion">This function is normally only called by backend programs to read
 commands from a filter, driver, or port monitor program.  The
 caller must be prepared to handle incomplete or invalid messages
 and return the corresponding status codes.<br>
@@ -1364,30 +1555,25 @@ pointed to by the &quot;data&quot; parameter.  cupsSideChannelDoRequest() will
 update the value to contain the number of data bytes in the buffer.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.4/Mac OS X 10.6&nbsp;</span><a name="cupsSideChannelSNMPGet">cupsSideChannelSNMPGet</a></h3>
-<p class="description">Query a SNMP OID's value.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.4/macOS 10.6&#160;</span><a id="cupsSideChannelSNMPGet">cupsSideChannelSNMPGet</a></h3>
+        <p class="description">Query a SNMP OID's value.</p>
 <p class="code">
-<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelSNMPGet (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *oid,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;char *data,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;int *datalen,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelSNMPGet(const char *oid, char *data, int *datalen, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>oid</dt>
-<dd class="description">OID to query</dd>
-<dt>data</dt>
-<dd class="description">Buffer for OID value</dd>
-<dt>datalen</dt>
-<dd class="description">Size of OID buffer on entry, size of value on return</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>oid</th>
+        <td class="description">OID to query</td></tr>
+<tr><th>data</th>
+        <td class="description">Buffer for OID value</td></tr>
+<tr><th>datalen</th>
+        <td class="description">Size of OID buffer on entry, size of value on return</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Query status</p>
+        <p class="description">Query status</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function asks the backend to do a SNMP OID query on behalf of the
+        <p class="discussion">This function asks the backend to do a SNMP OID query on behalf of the
 filter, port monitor, or backend using the default community name.<br>
 <br>
 &quot;oid&quot; contains a numeric OID consisting of integers separated by periods,
@@ -1405,30 +1591,25 @@ support SNMP queries.  <code>CUPS_SC_STATUS_NO_RESPONSE</code> is returned when
 the printer does not respond to the SNMP query.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.4/Mac OS X 10.6&nbsp;</span><a name="cupsSideChannelSNMPWalk">cupsSideChannelSNMPWalk</a></h3>
-<p class="description">Query multiple SNMP OID values.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.4/macOS 10.6&#160;</span><a id="cupsSideChannelSNMPWalk">cupsSideChannelSNMPWalk</a></h3>
+        <p class="description">Query multiple SNMP OID values.</p>
 <p class="code">
-<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelSNMPWalk (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *oid,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_walk_func_t">cups_sc_walk_func_t</a> cb,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;void *context<br>
-);</p>
+<a href="#cups_sc_status_t">cups_sc_status_t</a> cupsSideChannelSNMPWalk(const char *oid, double timeout, <a href="#cups_sc_walk_func_t">cups_sc_walk_func_t</a> cb, void *context);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>oid</dt>
-<dd class="description">First numeric OID to query</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout for each query in seconds</dd>
-<dt>cb</dt>
-<dd class="description">Function to call with each value</dd>
-<dt>context</dt>
-<dd class="description">Application-defined pointer to send to callback</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>oid</th>
+        <td class="description">First numeric OID to query</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout for each query in seconds</td></tr>
+<tr><th>cb</th>
+        <td class="description">Function to call with each value</td></tr>
+<tr><th>context</th>
+        <td class="description">Application-defined pointer to send to callback</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">Status of first query of <code>CUPS_SC_STATUS_OK</code> on success</p>
+        <p class="description">Status of first query of <code>CUPS_SC_STATUS_OK</code> on success</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function asks the backend to do multiple SNMP OID queries on behalf
+        <p class="discussion">This function asks the backend to do multiple SNMP OID queries on behalf
 of the filter, port monitor, or backend using the default community name.
 All OIDs under the &quot;parent&quot; OID are queried and the results are sent to
 the callback function you provide.<br>
@@ -1451,175 +1632,133 @@ support SNMP queries.  <code>CUPS_SC_STATUS_NO_RESPONSE</code> is returned when
 the printer does not respond to the first SNMP query.
 
 </p>
-<h3 class="function"><span class="info">&nbsp;CUPS 1.3/Mac OS X 10.5&nbsp;</span><a name="cupsSideChannelWrite">cupsSideChannelWrite</a></h3>
-<p class="description">Write a side-channel message.</p>
+<h3 class="function"><span class="info">&#160;CUPS 1.3/macOS 10.5&#160;</span><a id="cupsSideChannelWrite">cupsSideChannelWrite</a></h3>
+        <p class="description">Write a side-channel message.</p>
 <p class="code">
-int cupsSideChannelWrite (<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_command_t">cups_sc_command_t</a> command,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_sc_status_t">cups_sc_status_t</a> status,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;const char *data,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;int datalen,<br>
-&nbsp;&nbsp;&nbsp;&nbsp;double timeout<br>
-);</p>
+int cupsSideChannelWrite(<a href="#cups_sc_command_t">cups_sc_command_t</a> command, <a href="#cups_sc_status_t">cups_sc_status_t</a> status, const char *data, int datalen, double timeout);</p>
 <h4 class="parameters">Parameters</h4>
-<dl>
-<dt>command</dt>
-<dd class="description">Command code</dd>
-<dt>status</dt>
-<dd class="description">Status code</dd>
-<dt>data</dt>
-<dd class="description">Data buffer pointer</dd>
-<dt>datalen</dt>
-<dd class="description">Number of bytes of data</dd>
-<dt>timeout</dt>
-<dd class="description">Timeout in seconds</dd>
-</dl>
+<table class="list"><tbody>
+<tr><th>command</th>
+        <td class="description">Command code</td></tr>
+<tr><th>status</th>
+        <td class="description">Status code</td></tr>
+<tr><th>data</th>
+        <td class="description">Data buffer pointer</td></tr>
+<tr><th>datalen</th>
+        <td class="description">Number of bytes of data</td></tr>
+<tr><th>timeout</th>
+        <td class="description">Timeout in seconds</td></tr>
+</tbody></table>
 <h4 class="returnvalue">Return Value</h4>
-<p class="description">0 on success, -1 on error</p>
+        <p class="description">0 on success, -1 on error</p>
 <h4 class="discussion">Discussion</h4>
-<p class="discussion">This function is normally only called by backend programs to send
+        <p class="discussion">This function is normally only called by backend programs to send
 responses to a filter, driver, or port monitor program.
 
 </p>
-<h2 class="title"><a name="TYPES">Data Types</a></h2>
-<h3 class="typedef"><a name="cups_backend_t">cups_backend_t</a></h3>
-<p class="description">Backend exit codes</p>
-<p class="code">
+      <h2 class="title"><a id="TYPES">Data Types</a></h2>
+      <h3 class="typedef"><a id="cups_backend_t">cups_backend_t</a></h3>
+        <p class="description">Backend exit codes</p>
+      <p class="code">
 typedef enum <a href="#cups_backend_e">cups_backend_e</a> cups_backend_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_bidi_t">cups_sc_bidi_t</a></h3>
-<p class="description">Bidirectional capabilities</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_bidi_t">cups_sc_bidi_t</a></h3>
+        <p class="description">Bidirectional capabilities</p>
+      <p class="code">
 typedef enum <a href="#cups_sc_bidi_e">cups_sc_bidi_e</a> cups_sc_bidi_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_command_t">cups_sc_command_t</a></h3>
-<p class="description">Request command codes</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_command_t">cups_sc_command_t</a></h3>
+        <p class="description">Request command codes</p>
+      <p class="code">
 typedef enum <a href="#cups_sc_command_e">cups_sc_command_e</a> cups_sc_command_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_connected_t">cups_sc_connected_t</a></h3>
-<p class="description">Connectivity values</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_connected_t">cups_sc_connected_t</a></h3>
+        <p class="description">Connectivity values</p>
+      <p class="code">
 typedef enum <a href="#cups_sc_connected_e">cups_sc_connected_e</a> cups_sc_connected_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_state_t">cups_sc_state_t</a></h3>
-<p class="description">Printer state bits</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_state_t">cups_sc_state_t</a></h3>
+        <p class="description">Printer state bits</p>
+      <p class="code">
 typedef enum <a href="#cups_sc_state_e">cups_sc_state_e</a> cups_sc_state_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_status_t">cups_sc_status_t</a></h3>
-<p class="description">Response status codes</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_status_t">cups_sc_status_t</a></h3>
+        <p class="description">Response status codes</p>
+      <p class="code">
 typedef enum <a href="#cups_sc_status_e">cups_sc_status_e</a> cups_sc_status_t;
 </p>
-<h3 class="typedef"><a name="cups_sc_walk_func_t">cups_sc_walk_func_t</a></h3>
-<p class="description">SNMP walk callback</p>
-<p class="code">
+      <h3 class="typedef"><a id="cups_sc_walk_func_t">cups_sc_walk_func_t</a></h3>
+        <p class="description">SNMP walk callback</p>
+      <p class="code">
 typedef void (*cups_sc_walk_func_t)(const char *oid, const char *data, int datalen, void *context);
 </p>
-<h2 class="title"><a name="ENUMERATIONS">Constants</a></h2>
-<h3 class="enumeration"><a name="cups_backend_e">cups_backend_e</a></h3>
-<p class="description">Backend exit codes</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_BACKEND_AUTH_REQUIRED </dt>
-<dd class="description">Job failed, authentication required</dd>
-<dt>CUPS_BACKEND_CANCEL </dt>
-<dd class="description">Job failed, cancel job</dd>
-<dt>CUPS_BACKEND_FAILED </dt>
-<dd class="description">Job failed, use error-policy</dd>
-<dt>CUPS_BACKEND_HOLD </dt>
-<dd class="description">Job failed, hold job</dd>
-<dt>CUPS_BACKEND_OK </dt>
-<dd class="description">Job completed successfully</dd>
-<dt>CUPS_BACKEND_RETRY </dt>
-<dd class="description">Job failed, retry this job later</dd>
-<dt>CUPS_BACKEND_RETRY_CURRENT </dt>
-<dd class="description">Job failed, retry this job immediately</dd>
-<dt>CUPS_BACKEND_STOP </dt>
-<dd class="description">Job failed, stop queue</dd>
-</dl>
-<h3 class="enumeration"><a name="cups_sc_bidi_e">cups_sc_bidi_e</a></h3>
-<p class="description">Bidirectional capability values</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_SC_BIDI_NOT_SUPPORTED </dt>
-<dd class="description">Bidirectional I/O is not supported</dd>
-<dt>CUPS_SC_BIDI_SUPPORTED </dt>
-<dd class="description">Bidirectional I/O is supported</dd>
-</dl>
-<h3 class="enumeration"><a name="cups_sc_command_e">cups_sc_command_e</a></h3>
-<p class="description">Request command codes</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_SC_CMD_DRAIN_OUTPUT </dt>
-<dd class="description">Drain all pending output</dd>
-<dt>CUPS_SC_CMD_GET_BIDI </dt>
-<dd class="description">Return bidirectional capabilities</dd>
-<dt>CUPS_SC_CMD_GET_CONNECTED <span class="info">&nbsp;CUPS 1.5/Mac OS X 10.7&nbsp;</span></dt>
-<dd class="description">Return whether the backend is &quot;connected&quot; to the printer </dd>
-<dt>CUPS_SC_CMD_GET_DEVICE_ID </dt>
-<dd class="description">Return the IEEE-1284 device ID</dd>
-<dt>CUPS_SC_CMD_GET_STATE </dt>
-<dd class="description">Return the device state</dd>
-<dt>CUPS_SC_CMD_SNMP_GET <span class="info">&nbsp;CUPS 1.4/Mac OS X 10.6&nbsp;</span></dt>
-<dd class="description">Query an SNMP OID </dd>
-<dt>CUPS_SC_CMD_SNMP_GET_NEXT <span class="info">&nbsp;CUPS 1.4/Mac OS X 10.6&nbsp;</span></dt>
-<dd class="description">Query the next SNMP OID </dd>
-<dt>CUPS_SC_CMD_SOFT_RESET </dt>
-<dd class="description">Do a soft reset</dd>
-</dl>
-<h3 class="enumeration"><a name="cups_sc_connected_e">cups_sc_connected_e</a></h3>
-<p class="description">Connectivity values</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_SC_CONNECTED </dt>
-<dd class="description">Backend is &quot;connected&quot; to printer</dd>
-<dt>CUPS_SC_NOT_CONNECTED </dt>
-<dd class="description">Backend is not &quot;connected&quot; to printer</dd>
-</dl>
-<h3 class="enumeration"><a name="cups_sc_state_e">cups_sc_state_e</a></h3>
-<p class="description">Printer state bits</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_SC_STATE_BUSY </dt>
-<dd class="description">Device is busy</dd>
-<dt>CUPS_SC_STATE_ERROR </dt>
-<dd class="description">Other error condition</dd>
-<dt>CUPS_SC_STATE_MARKER_EMPTY </dt>
-<dd class="description">Toner/ink out condition</dd>
-<dt>CUPS_SC_STATE_MARKER_LOW </dt>
-<dd class="description">Toner/ink low condition</dd>
-<dt>CUPS_SC_STATE_MEDIA_EMPTY </dt>
-<dd class="description">Paper out condition</dd>
-<dt>CUPS_SC_STATE_MEDIA_LOW </dt>
-<dd class="description">Paper low condition</dd>
-<dt>CUPS_SC_STATE_OFFLINE </dt>
-<dd class="description">Device is offline</dd>
-<dt>CUPS_SC_STATE_ONLINE </dt>
-<dd class="description">Device is online</dd>
-</dl>
-<h3 class="enumeration"><a name="cups_sc_status_e">cups_sc_status_e</a></h3>
-<p class="description">Response status codes</p>
-<h4 class="constants">Constants</h4>
-<dl>
-<dt>CUPS_SC_STATUS_BAD_MESSAGE </dt>
-<dd class="description">The command/response message was invalid</dd>
-<dt>CUPS_SC_STATUS_IO_ERROR </dt>
-<dd class="description">An I/O error occurred</dd>
-<dt>CUPS_SC_STATUS_NONE </dt>
-<dd class="description">No status</dd>
-<dt>CUPS_SC_STATUS_NOT_IMPLEMENTED </dt>
-<dd class="description">Command not implemented</dd>
-<dt>CUPS_SC_STATUS_NO_RESPONSE </dt>
-<dd class="description">The device did not respond</dd>
-<dt>CUPS_SC_STATUS_OK </dt>
-<dd class="description">Operation succeeded</dd>
-<dt>CUPS_SC_STATUS_TIMEOUT </dt>
-<dd class="description">The backend did not respond</dd>
-<dt>CUPS_SC_STATUS_TOO_BIG </dt>
-<dd class="description">Response too big</dd>
-</dl>
-</div>
-</body>
+      <h2 class="title"><a id="ENUMERATIONS">Constants</a></h2>
+      <h3 class="enumeration"><a id="cups_backend_e">cups_backend_e</a></h3>
+        <p class="description">Backend exit codes</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_BACKEND_AUTH_REQUIRED </th>        <td class="description">Job failed, authentication required</td></tr>
+        <tr><th>CUPS_BACKEND_CANCEL </th>        <td class="description">Job failed, cancel job</td></tr>
+        <tr><th>CUPS_BACKEND_FAILED </th>        <td class="description">Job failed, use error-policy</td></tr>
+        <tr><th>CUPS_BACKEND_HOLD </th>        <td class="description">Job failed, hold job</td></tr>
+        <tr><th>CUPS_BACKEND_OK </th>        <td class="description">Job completed successfully</td></tr>
+        <tr><th>CUPS_BACKEND_RETRY </th>        <td class="description">Job failed, retry this job later</td></tr>
+        <tr><th>CUPS_BACKEND_RETRY_CURRENT </th>        <td class="description">Job failed, retry this job immediately</td></tr>
+        <tr><th>CUPS_BACKEND_STOP </th>        <td class="description">Job failed, stop queue</td></tr>
+</tbody></table>
+      <h3 class="enumeration"><a id="cups_sc_bidi_e">cups_sc_bidi_e</a></h3>
+        <p class="description">Bidirectional capability values</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_SC_BIDI_NOT_SUPPORTED </th>        <td class="description">Bidirectional I/O is not supported</td></tr>
+        <tr><th>CUPS_SC_BIDI_SUPPORTED </th>        <td class="description">Bidirectional I/O is supported</td></tr>
+</tbody></table>
+      <h3 class="enumeration"><a id="cups_sc_command_e">cups_sc_command_e</a></h3>
+        <p class="description">Request command codes</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_SC_CMD_DRAIN_OUTPUT </th>        <td class="description">Drain all pending output</td></tr>
+        <tr><th>CUPS_SC_CMD_GET_BIDI </th>        <td class="description">Return bidirectional capabilities</td></tr>
+        <tr><th>CUPS_SC_CMD_GET_CONNECTED <span class="info">&#160;CUPS 1.5/macOS 10.7&#160;</span></th>        <td class="description">Return whether the backend is &quot;connected&quot; to the printer </td></tr>
+        <tr><th>CUPS_SC_CMD_GET_DEVICE_ID </th>        <td class="description">Return the IEEE-1284 device ID</td></tr>
+        <tr><th>CUPS_SC_CMD_GET_STATE </th>        <td class="description">Return the device state</td></tr>
+        <tr><th>CUPS_SC_CMD_SNMP_GET <span class="info">&#160;CUPS 1.4/macOS 10.6&#160;</span></th>        <td class="description">Query an SNMP OID </td></tr>
+        <tr><th>CUPS_SC_CMD_SNMP_GET_NEXT <span class="info">&#160;CUPS 1.4/macOS 10.6&#160;</span></th>        <td class="description">Query the next SNMP OID </td></tr>
+        <tr><th>CUPS_SC_CMD_SOFT_RESET </th>        <td class="description">Do a soft reset</td></tr>
+</tbody></table>
+      <h3 class="enumeration"><a id="cups_sc_connected_e">cups_sc_connected_e</a></h3>
+        <p class="description">Connectivity values</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_SC_CONNECTED </th>        <td class="description">Backend is &quot;connected&quot; to printer</td></tr>
+        <tr><th>CUPS_SC_NOT_CONNECTED </th>        <td class="description">Backend is not &quot;connected&quot; to printer</td></tr>
+</tbody></table>
+      <h3 class="enumeration"><a id="cups_sc_state_e">cups_sc_state_e</a></h3>
+        <p class="description">Printer state bits</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_SC_STATE_BUSY </th>        <td class="description">Device is busy</td></tr>
+        <tr><th>CUPS_SC_STATE_ERROR </th>        <td class="description">Other error condition</td></tr>
+        <tr><th>CUPS_SC_STATE_MARKER_EMPTY </th>        <td class="description">Toner/ink out condition</td></tr>
+        <tr><th>CUPS_SC_STATE_MARKER_LOW </th>        <td class="description">Toner/ink low condition</td></tr>
+        <tr><th>CUPS_SC_STATE_MEDIA_EMPTY </th>        <td class="description">Paper out condition</td></tr>
+        <tr><th>CUPS_SC_STATE_MEDIA_LOW </th>        <td class="description">Paper low condition</td></tr>
+        <tr><th>CUPS_SC_STATE_OFFLINE </th>        <td class="description">Device is offline</td></tr>
+        <tr><th>CUPS_SC_STATE_ONLINE </th>        <td class="description">Device is online</td></tr>
+</tbody></table>
+      <h3 class="enumeration"><a id="cups_sc_status_e">cups_sc_status_e</a></h3>
+        <p class="description">Response status codes</p>
+      <h4 class="constants">Constants</h4>
+      <table class="list"><tbody>
+        <tr><th>CUPS_SC_STATUS_BAD_MESSAGE </th>        <td class="description">The command/response message was invalid</td></tr>
+        <tr><th>CUPS_SC_STATUS_IO_ERROR </th>        <td class="description">An I/O error occurred</td></tr>
+        <tr><th>CUPS_SC_STATUS_NONE </th>        <td class="description">No status</td></tr>
+        <tr><th>CUPS_SC_STATUS_NOT_IMPLEMENTED </th>        <td class="description">Command not implemented</td></tr>
+        <tr><th>CUPS_SC_STATUS_NO_RESPONSE </th>        <td class="description">The device did not respond</td></tr>
+        <tr><th>CUPS_SC_STATUS_OK </th>        <td class="description">Operation succeeded</td></tr>
+        <tr><th>CUPS_SC_STATUS_TIMEOUT </th>        <td class="description">The backend did not respond</td></tr>
+        <tr><th>CUPS_SC_STATUS_TOO_BIG </th>        <td class="description">Response too big</td></tr>
+</tbody></table>
+    </div>
+  </body>
 </html>