eeefccfcd1
(So far, just a new title, some minor updates, and a disclaimer in each section that has to be updated for the net release, or at least looked at.)
91 lines
4.7 KiB
Plaintext
91 lines
4.7 KiB
Plaintext
@chapter What is it?
|
|
|
|
The Cygwin tools are ports of the popular GNU development tools
|
|
for Windows NT, 95, and 98. They run thanks to the Cygwin library which
|
|
provides the UNIX system calls and environment these programs expect.
|
|
|
|
With these tools installed, it is possible to 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 packages
|
|
included with the Cygwin development tools themselves). Even if
|
|
the development tools are of little to no use to you, you may have
|
|
interest in the many standard Unix utilities provided with the package.
|
|
They can be used both from the bash shell (provided) or from the
|
|
standard Windows command shell.
|
|
|
|
@section Is it free software?
|
|
|
|
Yes. Parts are GNU software (gcc, gas, ld, etc...), parts are covered
|
|
by the standard X11 license, some of it is public domain, some of
|
|
it was written by Cygnus and placed under the 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 more more information on
|
|
how the GNU General Public License may affect your use of these tools.
|
|
|
|
In particular, if you intend to port a proprietary (non-GPL'd)
|
|
application using Cygwin, you will need the proprietary-use license
|
|
for the Cygwin library. This is available for purchase; please
|
|
contact sales@@cygnus.com for more information.
|
|
All other questions should be sent to the project
|
|
mailing list cygwin@@sourceware.cygnus.com.
|
|
|
|
Note that when we say "free" we mean freedom, not price. The goal of
|
|
such freedom is that the people who use a given piece of software
|
|
should be able to change it to fit their needs, learn from it, share
|
|
it with their friends, etc. The Cygwin license allows you those
|
|
freedoms, so it is free software.
|
|
|
|
The Cygwin 1.0 product is a "commercial" distribution of cygwin. As
|
|
such, it includes such non-software things as printed manuals, support,
|
|
and aggregation of useful utilities. There is nothing (software-wise)
|
|
in there that you can't already get off the net already, if you take the
|
|
time to find and download everything (and usually, build it yourself),
|
|
although the @emph{versions} available for download may be different
|
|
than those distributed with the commercial product. We test it all to
|
|
make sure it works together, and package it in a convenient form. We
|
|
consider such testing and packaging to be a valuable service and thus
|
|
charge a fee for it. Plus, it provides income for the cygwin project so
|
|
we can continue working on it. For further details about the commercial
|
|
product, see @file{http://www.cygnus.com/cygwin/}.
|
|
|
|
@section A brief history of the project
|
|
|
|
@strong{(Please note: This section has not yet been updated for the latest
|
|
net release.)}
|
|
|
|
The first thing done was to enhance the development tools (gcc, gdb,
|
|
gas, et al) so that they could generate/interpret Win32 native object
|
|
files.
|
|
|
|
The next task was to port the tools to Win NT/95. 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 (cygwin.dll) that adds
|
|
the necessary unix-like functionality missing from the Win32 API (fork,
|
|
spawn, signals, select, sockets, 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.
|
|
|
|
From this point, we pursued the goal of producing native tools capable of
|
|
rebuilding themselves under Windows 95 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 95 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.
|
|
|
|
After adding Windows 98 support to Cygwin in mid-1998, we added support
|
|
for the native Microsoft libraries in the compiler which allows
|
|
compilation of executables that do not use Cygwin. This is important to
|
|
those people who want to use the tools to develop Win32 applications
|
|
that do not need the UNIX emulation layer.
|