Cygwin use windows dll

Cygwin is not a full operating system, and so must rely on Windows for accomplishing some tasks. For example, Cygwin provides a POSIX view of the Windows filesystem, but does not provide filesystem drivers of its own. Therefore part of using Cygwin effectively is learning to use Windows effectively. Many Windows utilities provide a good way to interact with Cygwin’s predominately command-line environment. For example, ipconfig.exe provides information about network configuration, and net.exe views and configures network file and printer resources. Most of these tools support the /? switch to display usage information.

Unfortunately, no standard set of tools included with all versions of Windows exists. Generally, the younger the Windows version, the more complete are the on-board tools. Additionally, many independent sites such as download.com, simtel.net, and Microsoft’s own Sysinternals provide quite useful command-line utilities, as far as they are not already provided by Cygwin. A few Windows tools, such as find.exe , link.exe and sort.exe , may conflict with the Cygwin versions make sure that you use the full path ( /usr/bin/find ) or that your Cygwin bin directory comes first in your PATH .

Pathnames

Windows programs do not understand POSIX pathnames, so any arguments that reference the filesystem must be in Windows (or DOS) format or translated. Cygwin provides the cygpath utility for converting between Windows and POSIX paths. A complete description of its options and examples of its usage are in cygpath (1), including a shell script for starting Windows Explorer in any directory. The same format works for most Windows programs, for example

A few programs require a Windows-style, semicolon-delimited path list, which cygpath can translate from a POSIX path with the -p option. For example, a Java compilation from bash might look like this:

Since using quoting and subshells is somewhat awkward, it is often preferable to use cygpath in shell scripts.

Cygwin and Windows Networking

Many popular Cygwin packages, such as ncftp , lynx , and wget , require a network connection. Since Cygwin relies on Windows for connectivity, if one of these tools is not working as expected you may need to troubleshoot using Windows tools. The first test is to see if you can reach the URL’s host with ping.exe , one of the few utilities included with every Windows version since Windows 95. If you chose to install the inetutils package, you may have both Windows and Cygwin versions of utilities such as ftp and telnet . If you are having problems using one of these programs, see if the alternate one works as expected.

There are a variety of other programs available for specific situations. If your system does not have an always-on network connection, you may be interested in rasdial.exe for automating dialup connections. Users who frequently change their network configuration can script these changes with netsh.exe . For proxy users, the open source NTLM Authorization Proxy Server or the no-charge Hummingbird SOCKS Proxy may allow you to use Cygwin network programs in your environment.

Creating shortcuts

By default, Cygwin does not create symlinks as .lnk files, but there’s an option to do that, see the section called “The CYGWIN environment variable”. These symlink .lnk files are compatible with Windows-created .lnk files, but they are still different. They do not include much of the information that is available in a standard Microsoft shortcut, such as the working directory, an icon, etc. The cygutils package includes a mkshortcut utility for creating standard native Microsoft .lnk files from the command line.

But here’s the problem. If Cygwin handled these native shortcuts like any other symlink, you could not archive Microsoft .lnk files into tar archives and keep all the information in them. After unpacking, these shortcuts would have lost all the extra information and would be no different than standard Cygwin symlinks. Therefore these two types of links are treated differently. Unfortunately, this means that the usual Unix way of creating and using symlinks does not work with native Windows shortcuts.

Printing

There are several options for printing from Cygwin, including the lpr found in cygutils-extra (not to be confused with the native Windows lpr.exe ). The easiest way to use cygutils-extra ‘s lpr is to specify a default device name in the PRINTER environment variable. You may also specify a device on the command line with the -d or -P options, which will override the environment variable setting.

A device name may be a UNC path ( \\server_name\printer_name ), a reserved DOS device name ( prn , lpt1 ), or a local port name that is mapped to a printer share. Note that forward slashes may be used in a UNC path ( //server_name/printer_name ), which is helpful when using lpr from a shell that uses the backslash as an escape character.

lpr sends raw data to the printer; no formatting is done. Many, but not all, printers accept plain text as input. If your printer supports PostScript, packages such as a2ps and enscript can prepare text files for printing. The ghostscript package also provides some translation from PostScript to various native printer languages. Additionally, a native Windows application for printing PostScript, gsprint , is available from the Ghostscript website.

Cygwin

Get that Linux feeling — on Windows

This is the home of the Cygwin project

. is it?

• a large collection of GNU and Open Source tools which provide functionality similar to a Linux distribution on Windows.
• a DLL (cygwin1.dll) which provides substantial POSIX API functionality.

. isn’t it?

• a way to run native Linux apps on Windows. You must rebuild your application from source if you want it to run on Windows.
• a way to magically make native Windows apps aware of UNIX® functionality like signals, ptys, etc. Again, you need to build your apps from source if you want to take advantage of Cygwin functionality.

The Cygwin DLL currently works with all recent, commercially released x86_64 versions of Windows, starting with Windows Vista. For more information see the FAQ.

Cygwin version

The most recent version of the Cygwin DLL is 3.2.0.

Installing Cygwin

Use the setup program to perform a fresh install or to update an existing installation.

Keep in mind that individual packages in the distribution are updated separately from the DLL so the Cygwin DLL version is not useful as a general Cygwin distribution release number.

Support for Cygwin

For all Cygwin-related questions and observations, please check the resources available at this site, such as the FAQ, the User’s Guide and the mailing list archives. If you’ve exhausted these resources then please send email to an appropriate mailing list. This includes observations about web pages, setup questions, questions about where to find things, questions about why things are done a certain way, questions about the color preferences of Cygwin developers, questions about the meaning of the number 42, etc.

Please send notification of technical problems (bad html, broken links) concerning these web pages to the Cygwin mailing list.

Please do not send personal email with «quick questions» to individual Cygwin contributors. The Cygwin mailing lists are the places for all questions. Really. I mean it.

32 bit Cygwin

Address space is a very limiting factor for Cygwin. These days, a full 32 bit Cygwin distro is not feasible anymore, and will in all likelihood fail in random places due to an issue with the fork(2) system call.

Therefore we recommend using 32 bit Cygwin only in limited scenarios, with only a minimum of necessary packages installed, and only if there’s no way to run 64 bit Cygwin instead.

You have been warned. If you’re still sure you really need a 32 bit Cygwin, and there’s absolutely no way around it, you may run the setup-x86.exe installer.

The Cygwin DLL and utilities are Copyright © Cygwin authors. Other packages have other copyrights.
UNIX ® is a registered trademark of the Open Group in the United States and other countries.

Cygwin use windows dll

DLLs are Dynamic Link Libraries, which means that they’re linked into your program at run time instead of build time. There are three parts to a DLL:

the code and data

the import library

The code and data are the parts you write — functions, variables, etc. All these are merged together, like if you were building one big object files, and put into the dll. They are not put into your .exe at all.

The exports contains a list of functions and variables that the dll makes available to other programs. Think of this as the list of «global» symbols, the rest being hidden. Normally, you’d create this list by hand with a text editor, but it’s possible to do it automatically from the list of functions in your code. The dlltool program creates the exports section of the dll from your text file of exported symbols.

The import library is a regular UNIX-like .a library, but it only contains the tiny bit of information needed to tell the OS how your program interacts with («imports») the dll. This information is linked into your .exe . This is also generated by dlltool .

Building DLLs

This page gives only a few simple examples of gcc’s DLL-building capabilities. To begin an exploration of the many additional options, see the gcc documentation and website, currently at http://gcc.gnu.org/

Let’s go through a simple example of how to build a dll. For this example, we’ll use a single file myprog.c for the program ( myprog.exe ) and a single file mydll.c for the contents of the dll ( mydll.dll ).

Fortunately, with the latest gcc and binutils the process for building a dll is now pretty simple. Say you want to build this minimal function in mydll.c:

First compile mydll.c to object code:

Then, tell gcc that it is building a shared library:

That’s it! To finish up the example, you can now link to the dll with a simple program:

Then link to your dll with a command like:

However, if you are building a dll as an export library, you will probably want to use the complete syntax:

The name of your library is $ , prefixed with cyg for the DLL and lib for the import library. Cygwin DLLs use the cyg prefix to differentiate them from native-Windows MinGW DLLs, see the MinGW website for more details. $ are all your object files, bundled together in static libs or single object files and the $ are import libs you need to link against, e.g ‘-lpng -lz -L/usr/local/special -lmyspeciallib’ .

Linking Against DLLs

If you have an existing DLL already, you need to build a Cygwin-compatible import library. If you have the source to compile the DLL, see the section called “Building DLLs” for details on having gcc build one for you. If you do not have the source or a supplied working import library, you can get most of the way by creating a .def file with these commands (you might need to do this in bash for the quoting to work correctly):

Note that this will only work if the DLL is not stripped. Otherwise you will get an error message: «No symbols in foo.dll».

Once you have the .def file, you can create an import library from it like this:

Cygwin

Get that Linux feeling — on Windows

Installing and Updating Cygwin Packages

Installing and Updating Cygwin for 64-bit versions of Windows

Run setup-x86_64.exe any time you want to update or install a Cygwin package for 64-bit windows. The signature for setup-x86_64.exe can be used to verify the validity of this binary.

Installing and Updating Cygwin for 32-bit versions of Windows

Run setup-x86.exe any time you want to update or install a Cygwin package for 32-bit windows. The signature for setup-x86.exe can be used to verify the validity of this binary.

Signing key transition

See this mail for more details.

General installation notes

When installing packages for the first time, the setup program does not install every package. Only the minimal base packages from the Cygwin distribution are installed by default, which takes up about 100 MB.

Clicking on categories and packages in the setup program package installation screen allows you to select what is installed or updated.

Individual packages like bash, gcc, less, etc. are released independently of the Cygwin DLL, so the Cygwin DLL version is not useful as a general Cygwin release number. The setup program tracks the versions of all installed components and provides the mechanism for installing or updating everything available from this site for Cygwin.

Once you’ve installed your desired subset of the Cygwin distribution, the setup program will remember what you selected, so re-running it will update your system with any new package releases.

On Windows Vista and later, the setup program will check by default if it runs with administrative privileges and, if not, will try to elevate the process. If you want to avoid this behaviour and install under an unprivileged account just for your own usage, run setup with the --no-admin option.

Q: How do I add a package to my existing Cygwin installation?

A: Run the setup program and select the package you want to add.

Tip: if you don’t want to also upgrade existing packages, select ‘Keep’ at the top-right of the package chooser page.

Q: Is there a command-line installer?

A: Yes and no. The setup program understands command-line arguments which allow you to control its behavior and choose individual packages to install. While this provides some functionality similar to such tools as apt-get or yum it is not as full-featured as those package managers.

Q: Why not use apt, yum, my favourite package manager, etc.?

A: The basic reason for not using a more full-featured package manager is that such a program would need full access to all of Cygwin’s POSIX functionality. That is, however, difficult to provide in a Cygwin-free environment, such as exists on first installation. Additionally, Windows does not easily allow overwriting of in-use executables so installing a new version of the Cygwin DLL while a package manager is using the DLL is problematic.

Q: How do I install everything?

A: You do not want to do this! This will install an enormous number of packages that you will never use, including debuginfo and source for every package.

If you really must do this, clicking on the «Default» label next to the «All» category to change it to «Install» will mark every Cygwin package for installation. Be advised that this will download and install tens of gigabytes of files to your computer.