Report whether HTTPS URLs are supported (Issue #339)

Also added documentation to INSTALL.md about the libraries that are needed
(and other problematic ones)

Updated copyright to 2019.

CHANGES.md

@@ -8,6 +8,7 @@
   HTML keywords and lang values.
 - Added support for the subject and language metadata in markdown input.
 - Fixed a buffer underflow bug (Issue #338)
+- `htmldoc --help` now reports whether HTTPS URLs are supported (Issue #339)
 - Fixed an issue with HTML title pages and EPUB output.
 
 # Changes in HTMLDOC v1.9.4

INSTALL.md

@@ -1,4 +1,5 @@
-# How to Install HTMLDOC from Source
+How to Install HTMLDOC from Source
+==================================
 
 To compile HTMLDOC you'll need C and C++ compilers (gcc is fine, most vendor
 compilers work, too).  The JPEG, PNG, and ZLIB libraries are provided with
@@ -9,8 +10,11 @@ platform GUI toolkit and can be downloaded from:
 
     http://www.fltk.org/
 
+For HTTPS support you'll need GNU TLS on Linux and UNIX.
 
-## Windows
+
+Windows
+-------
 
 A Visual Studio solution is included in the "vcnet" directory.  You must add the
 FLTK include and library directories separately for the solution to build.
@@ -36,7 +40,8 @@ Then create the following registry entries with REGEDIT:
     HKEY_LOCAL_MACHINE\Software\HTMLDOC\data = C:\install\dir
 
 
-## Linux, macOS, and Other UNIX Platforms
+Linux, macOS, and Other UNIX Platforms
+--------------------------------------
 
 To compile the software under UNIX you first need to run the "configure" script
 in the source directory.  Usually this is just:
@@ -50,3 +55,23 @@ Then run "make" to build the software and generate the documentation:
 Finally, run "make install" (typically as root) to install the software:
 
     sudo make install
+
+
+Ubuntu Notes
+------------
+
+You should install the following packages:
+
+    sudo apt-get install build-essential autoconf libfltk1.3-dev \
+        libgnutls28-dev libjpeg-dev libpng-dev zlib1g-dev
+
+
+CentOS, Fedora, and RHEL Notes
+------------------------------
+
+The version of GCC bundled with older releases of these operating systems cannot
+handle the version of libpng that is bundled with HTMLDOC.  Install the
+following packages to avoid this and get full functionality:
+
+    sudo yum install autoconf fltk-devel gnutls-devel libjpeg-devel \
+    	libpng-devel zlib-devel

README.md

@@ -1,4 +1,5 @@
-# Introduction
+Introduction
+------------
 
 HTMLDOC is a program that reads HTML and Markdown source files or web pages and
 generates corresponding EPUB, HTML, PostScript, or PDF files with an optional
@@ -32,20 +33,22 @@ servers.  However, it does not support many things in "the modern web", such as:
 - Emoji: The fonts bundled with HTMLDOC do not include Unicode Emoji characters.
 
 
-# Resources
+Resources
+---------
 
 The following HTMLDOC resources are available online:
 
 - Official web site and online documentation:
 
-    https://michaelrsweet.github.io/htmldoc
+    https://www.msweet.org/htmldoc
 
 - Issue tracker and questions:
 
     https://github.com/michaelrsweet/htmldoc/issues
 
 
-# Using HTMLDOC
+Using HTMLDOC
+-------------
 
 Note: Complete documentation for HTMLDOC is available in the "doc" subdirectory.
 The following provides basic information on using HTMLDOC at the command-line
@@ -87,7 +90,8 @@ A complete description of all command-line options and HTML guidelines can be
 found in the software users manual in the "doc" directory.
 
 
-# Credits
+Credits
+-------
 
 Many thanks to Leonard Rosenthol for providing the original changes to support
 a macOS (9) version of HTMLDOC.
@@ -104,13 +108,14 @@ The MD5 hash code is from L. Peter Deutsch at Aladdin Enterprises (creators
 of Ghostscript, among other things).
 
 
-# Legal Stuff
+Legal Stuff
+-----------
 
-HTMLDOC is copyright © 1997-2018 by Michael R Sweet.  This program is free
+HTMLDOC is copyright © 1997-2019 by Michael R Sweet.  This program is free
 software.  Distribution and use rights are outlined in the file "COPYING".
 
 HTMLDOC includes code to encrypt PDF document files using the RC4 algorithm
-with up to a 128-bit key. While this software and code may be freely used
+with up to a 128-bit key.  While this software and code may be freely used
 and exported under current US laws, other countries may restrict your use
 and possession of this code and software.
 

doc/1-intro.html

@@ -1,7 +1,7 @@
 <html>
 <head>
 	<meta name="author" content="Michael R Sweet">
-	<meta name="copyright" content="Copyright &copy; 1997-2018, All Rights Reserved.">
+	<meta name="copyright" content="Copyright &copy; 1997-2019, All Rights Reserved.">
 	<meta name="docversion" content="htmldoc-1.9.5">
 	<meta name="keywords" content="Software">
 	<title>HTMLDOC Users Manual</title>
@@ -57,7 +57,7 @@ <h2>Encryption Support</h2>
 
 <h2>Legal Stuff</h2>
 
-<p>HTMLDOC is copyright &copy; 1997-2018 by Michael R Sweet. See <a href="#LICENSE">Appendix A - License Agreement</a> for the terms of use. This software is based in part on the work of the Independent JPEG Group and FLTK project.</p>
+<p>HTMLDOC is copyright &copy; 1997-2019 by Michael R Sweet. See <a href="#LICENSE">Appendix A - License Agreement</a> for the terms of use. This software is based in part on the work of the Independent JPEG Group and FLTK project.</p>
 
 </div>
 

htmldoc/gui.cxx

@@ -1,7 +1,7 @@
 //
 // GUI routines for HTMLDOC, an HTML document processing program.
 //
-// Copyright 2011-2018 by Michael R Sweet.
+// Copyright 2011-2019 by Michael R Sweet.
 // Copyright 1997-2010 by Easy Software Products.  All rights reserved.
 //
 // This program is free software.  Distribution and use rights are outlined in
@@ -4226,7 +4226,7 @@ GUI::showAboutCB(void)
   label->image(&logo);
 
   label = new Fl_Box(60, 45, 530, 35,
-          "HTMLDOC " SVERSION "\nCopyright 2011-2017 by Michael R Sweet."
+          "HTMLDOC " SVERSION "\nCopyright 2011-2019 by Michael R Sweet."
 	  );
   label->align(FL_ALIGN_TOP_LEFT | FL_ALIGN_INSIDE | FL_ALIGN_WRAP);
 

htmldoc/htmldoc.cxx

@@ -1,7 +1,7 @@
 /*
  * Main entry for HTMLDOC, a HTML document processing program.
  *
- * Copyright 2011-2017 by Michael R Sweet.
+ * Copyright 2011-2019 by Michael R Sweet.
  * Copyright 1997-2010 by Easy Software Products.  All rights reserved.
  *
  * This program is free software.  Distribution and use rights are outlined in
@@ -2590,12 +2590,19 @@ usage(const char *arg)			// I - Bad argument string
   if (CGIMode)
     puts("Content-Type: text/plain\r\n\r");
 
-  puts("HTMLDOC Version " SVERSION " Copyright 2011-2017 by Michael R Sweet.");
+  puts("HTMLDOC Version " SVERSION " Copyright 2011-2019 by Michael R Sweet.");
   puts("HTMLDOC is provided under the terms of the GNU General Public License and");
   puts("comes with absolutely no warranty.  This software is based in part on the work");
   puts("of the Independent JPEG Group.");
   puts("");
 
+#ifdef HAVE_SSL
+  puts("This copy of HTMLDOC has been built to support both http: and https: URLs.");
+#else
+  puts("This copy of HTMLDOC has been built to support http: URLs only.");
+#endif /* HAVE_SSL */
+  puts("");
+
   if (CGIMode)
   {
     puts("HTMLDOC is running in CGI mode.  To disable CGI mode when running");