Merge changes from CUPS 1.5svn-r9717.

git-svn-id: svn+ssh://src.apple.com/svn/cups/easysw/current@3171 a1ca3aef-8c08-0410-bb20-df032aa958be

1 files changed, 11 insertions, 4 deletions

diff --git a/cups/api-filter.shtml b/cups/api-filter.shtml
index 0af098f3f..e44c7063a 100644
--- a/cups/api-filter.shtml
+++ b/cups/api-filter.shtml
@@ -1,10 +1,9 @@
 <!--
   "$Id: api-filter.shtml 7677 2008-06-19 23:22:19Z mike $"
 
-  Filter and backend programming introduction for the Common UNIX Printing
-  System (CUPS).
+  Filter and backend programming introduction for CUPS.
 
-  Copyright 2007-2009 by Apple Inc.
+  Copyright 2007-2011 by Apple Inc.
   Copyright 1997-2006 by Easy Software Products, all rights reserved.
 
   These coded instructions, statements, and computer programs are the
@@ -85,6 +84,14 @@ 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>
 </blockquote>
 
+<h3><a name="SIGNALS">Signal Handling</a><h3>
+
+<p>The scheduler sends <code>SIGTERM</code> when a printing job is canceled or
+held. Filters, backends, and port monitors <em>must</em> catch
+<code>SIGTERM</code> and perform any cleanup necessary to produce a valid output
+file or return the printer to a known good state. The recommended behavior is to
+end the output on the current page.</p>
+
 <h3><a name="PERMISSIONS">File Permissions</a></h3>
 
 <p>For security reasons, CUPS will only run filters and backends that are owned
@@ -424,7 +431,7 @@ the "DEBUG:" prefix string.</p>
 <p>Filters can communicate with the backend via the
 <a href="#cupsBackChannelRead"><code>cupsBackChannelRead</code></a> and
 <a href="#cupsSideChannelDoRequest"><code>cupsSideChannelDoRequest</code></a>
-functions. The 
+functions. The
 <a href="#cupsBackChannelRead"><code>cupsBackChannelRead</code></a> function
 reads data that has been sent back from the device and is typically used to
 obtain status and configuration information. For example, the following code