49536558ef
* cygwinenv.sgml: Fix codepage:utf8 text in terms of setting environment variables. * new-features.sgml: New file describing new Cygwin 1.7 features. Layout is preliminiary only. * overview.sgml: Insert content of new-features.sgml.
123 lines
5.8 KiB
Plaintext
123 lines
5.8 KiB
Plaintext
<chapter id="overview"><title>Cygwin Overview</title>
|
|
|
|
<sect1 id="what-is-it"><title>What is it?</title>
|
|
|
|
<para>
|
|
Cygwin is a Linux-like environment for Windows. It consists of a DLL
|
|
(<filename>cygwin1.dll</filename>), which acts as an emulation layer
|
|
providing substantial <ulink url="http://www.pasc.org/#POSIX">POSIX</ulink>
|
|
(Portable Operating System Interface) system call functionality, and a
|
|
collection of tools, which provide a Linux look and feel. The Cygwin DLL
|
|
works with all x86 and AMD64 versions of Windows NT since Windows NT 4.
|
|
The API follows the
|
|
<ulink url="http://www.opengroup.org/onlinepubs/009695399/nfindex.html">Single
|
|
Unix Specification</ulink> as much as possible, and then Linux practice.
|
|
The major differences between Cygwin and Linux is the C library
|
|
(<literal>newlib</literal> instead of <literal>glibc</literal>).
|
|
</para>
|
|
<para>
|
|
With Cygwin installed, users have access to many standard UNIX
|
|
utilities. They can be used from one of the provided shells such
|
|
as <command>bash</command> or from the Windows Command Prompt.
|
|
Additionally, programmers may write Win32 console or GUI applications
|
|
that make use of the standard Microsoft Win32 API and/or the Cygwin API.
|
|
As a result, it is possible to easily port many significant UNIX
|
|
programs without the need for extensive changes to the source code.
|
|
This includes configuring and building most of the available GNU
|
|
software (including the development tools included with the Cygwin
|
|
distribution).
|
|
</para>
|
|
</sect1>
|
|
|
|
DOCTOOL-INSERT-ov-ex-win
|
|
DOCTOOL-INSERT-ov-ex-unix
|
|
|
|
<sect1 id="are-free"><title>Are the Cygwin tools free software?</title>
|
|
|
|
<para>Yes. Parts are <ulink url="http://www.gnu.org/">GNU</ulink> software
|
|
(<command>gcc</command>, <command>gas</command>, <command>ld</command>, etc.),
|
|
parts are covered by the standard
|
|
<ulink url="http://www.x.org/Downloads_terms.html">X11 license</ulink>,
|
|
some of it is public domain, some of it was written by Red Hat and placed under
|
|
the <ulink url="http://www.gnu.org/licenses/gpl.html">GNU General Public
|
|
License</ulink> (GPL). None of it is shareware. You don't have to pay anyone to
|
|
use it but you should be sure to read the copyright section of the FAQ for more
|
|
information on how the GNU GPL may affect your use of these
|
|
tools. If you intend to port a proprietary application using the Cygwin
|
|
library, you may want the Cygwin proprietary-use license.
|
|
For more information about the proprietary-use license, please go to
|
|
<ulink url="http://www.redhat.com/software/tools/cygwin/">http://www.redhat.com/software/tools/cygwin/</ulink>.
|
|
Customers of the native Win32 GNUPro should feel free to submit bug
|
|
reports and ask questions through the normal channels. All other
|
|
questions should be sent to the project mailing list
|
|
<email>cygwin@cygwin.com</email>.</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="brief-history"><title>A brief history of the Cygwin project</title>
|
|
|
|
<note>
|
|
<para>
|
|
A historical look into the first years of Cygwin development is
|
|
Geoffrey J. Noer's 1998 paper, "Cygwin32: A Free Win32 Porting Layer for
|
|
UNIX® Applications" which can be found at the <ulink
|
|
url="http://www.usenix.org/publications/library/proceedings/usenix-nt98/technical.html">
|
|
2nd USENIX Windows NT Symposium Online Proceedings</ulink>.
|
|
</para>
|
|
</note>
|
|
<para>
|
|
Cygwin began development in 1995 at Cygnus Solutions (now part of Red Hat
|
|
Software). The first thing done was to enhance the development tools
|
|
(<command>gcc</command>, <command>gdb</command>, <command>gas</command>,
|
|
etc.) so that they could generate and interpret Win32 native
|
|
object files.
|
|
The next task was to port the tools to Win NT/9x. We could have
|
|
done this by rewriting large portions of the source to work within the
|
|
context of the Win32 API. But this would have meant spending a huge
|
|
amount of time on each and every tool. Instead, we took a
|
|
substantially different approach by writing a shared library
|
|
(the Cygwin DLL) that adds the necessary UNIX-like functionality
|
|
missing from the Win32 API (<function>fork</function>,
|
|
<function>spawn</function>, <function>signals</function>,
|
|
<function>select</function>, <function>sockets</function>, etc.). We call this
|
|
new interface the Cygwin API. Once written, it was possible to build working
|
|
Win32 tools using UNIX-hosted cross-compilers, linking against this
|
|
library.</para>
|
|
|
|
<para>From this point, we pursued the goal of producing native tools
|
|
capable of rebuilding themselves under Windows 9x and NT (this is
|
|
often called self-hosting). Since neither OS ships with standard UNIX
|
|
user tools (fileutils, textutils, bash, etc...), we had to get the GNU
|
|
equivalents working with the Cygwin API. Most of these tools were
|
|
previously only built natively so we had to modify their configure
|
|
scripts to be compatible with cross-compilation. Other than the
|
|
configuration changes, very few source-level changes had to be
|
|
made. Running bash with the development tools and user tools in place,
|
|
Windows 9x and NT look like a flavor of UNIX from the perspective of
|
|
the GNU configure mechanism. Self hosting was achieved as of the beta
|
|
17.1 release in October 1996.</para>
|
|
|
|
<para>
|
|
The entire Cygwin toolset was available as a monolithic install. In
|
|
April 2000, the project announced a
|
|
<ulink url="http://www.cygwin.com/ml/cygwin/2000-04/msg00269.html">
|
|
New Cygwin Net Release</ulink> which provided the native Win32 program
|
|
<command>setup.exe</command> to install and upgrade each package
|
|
separately. Since then, the Cygwin DLL and <command>setup.exe</command>
|
|
have seen continuous development.
|
|
</para>
|
|
|
|
<para>
|
|
The latest major improvement in this development is the 1.7 release in
|
|
2009, which dropped Windows 95/98/Me support in favor of using Windows
|
|
NT features more extensively. It adds a lot of new features like
|
|
case-sensitive filenames, NFS interoperability, IPv6 support and much
|
|
more.</para>
|
|
|
|
</sect1>
|
|
|
|
DOCTOOL-INSERT-highlights
|
|
DOCTOOL-INSERT-ov-new1.7
|
|
|
|
</chapter>
|