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

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.

Chapter 2. Setting Up Cygwin

Table of Contents

Internet Setup

To install the Cygwin net release, go to https://cygwin.com/ and run either setup-x86.exe to install the 32 bit version of Cygwin, or setup-x86_64.exe to install the 64 bit version of Cygwin. This will download a GUI installer which can be run to download a complete cygwin installation via the internet. Follow the instructions on each screen to install Cygwin.

The setup.exe installer is designed to be easy for new users to understand while remaining flexible for the experienced. The volunteer development team is constantly working on setup.exe ; before requesting a new feature, check the wishlist in the Git README . It may already be present in the Git version!

On Windows Vista and later, setup.exe 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.exe with the —no-admin option.

Since the default value for each option is the logical choice for most installations, you can get a working minimal Cygwin environment installed by simply clicking the Next button at each page. The only exception to this is choosing a Cygwin mirror, which you can choose by experimenting with those listed at https://cygwin.com/mirrors.html. For more details about each of page of the setup.exe installation, read on below. Please note that this guide assumes that you have a basic understanding of Unix (or a Unix-like OS). If you are new to Unix, you will also want to make use of other resources.

Download Source

Cygwin uses packages to manage installing various software. When the default Install from Internet option is chosen, setup.exe creates a local directory to store the packages before actually installing the contents. Download from Internet performs only the first part (storing the packages locally), while Install from Local Directory performs only the second (installing the contents of the packages).

The Download from Internet option is mainly for creating a base Cygwin package tree on one computer for installation on several machines with Install from Local Directory ; copy the entire local package tree to another machine with the directory tree intact. For example, you might create a C:\cache\ directory and place setup.exe in it. Run setup.exe to Install from Internet or Download from Internet , then copy the whole C:\cache\ to each machine and instead choose Install from Local Directory .

Though this provides some basic mirroring functionality, if you are managing a large Cygwin installation, to keep up to date we recommend using a mirroring tool such as wget . A helpful user on the Cygwin mailing list created a simple demonstration script to accomplish this; search the list for mkcygwget for ideas.

Selecting an Install Directory

The Root Directory for Cygwin (default C:\cygwin ) will become / within your Cygwin installation. You must have write access to the parent directory, and any ACLs on the parent directory will determine access to installed files.

The Install For options of All Users or Just Me should always be left on the default All Users , unless you do not have write access to HKEY_LOCAL_MACHINE in the registry or the All Users Start Menu. This is true even if you are the only user planning to use Cygwin on the machine. Selecting Just Me will cause problems for programs such as crond and sshd . If you do not have the necessary permissions, but still want to use these programs, consult the Cygwin mailing list archives about others’ experiences.

Local Package Directory

The Local Package Directory is the cache where setup.exe stores the packages before they are installed. The cache must not be the same folder as the Cygwin root. Within the cache, a separate directory is created for each Cygwin mirror, which allows setup.exe to use multiple mirrors and custom packages. After installing Cygwin, the cache is no longer necessary, but you may want to retain the packages as backups, for installing Cygwin to another system, or in case you need to reinstall a package.

Connection Method

The Direct Connection method of downloading will directly connect. If your system is configured to use a proxy server or auto-configuration scripts, the Use System Proxy Settings method uses those settings. Alternatively, you can manually enter proxy settings into the Use HTTP/FTP Proxy section.

Choosing Mirrors

Since there is no way of knowing from where you will be downloading Cygwin, you need to choose at least one mirror site. Cygwin mirrors are geographically distributed around the world; check the list at https://cygwin.com/mirrors.html to find one near you. You can select multiple mirrors by holding down CTRL and clicking on each one. If you have the URL of an unlisted mirror (for example, if your organization has an internal Cygwin mirror) you can add it.

Choosing Packages

For each selected mirror site, setup.exe downloads a small text file called setup.bz2 that contains a list of packages available from that site along with some basic information about each package which setup.exe parses and uses to create the chooser window. For details about the format of this file, see the setup.exe homepage.

The chooser is the most complex part of setup.exe . Packages are grouped into categories, and one package may belong to multiple categories (assigned by the volunteer package maintainer). Each package can be found under any of those categories in the hierarchical chooser view. By default, setup.exe will install only the packages in the Base category and their dependencies, resulting in a minimal Cygwin installation. However, this will not include many commonly used tools such as gcc (which you will find in the Devel category). Since setup.exe automatically selects dependencies, be careful not to unselect any required packages. In particular, everything in the Base category is required.

You can change setup.exe ‘s view style, which is helpful if you know the name of a package you want to install but not which category it is in. Click on the View button and it will rotate between Category (the default), Full (all packages), and Pending (only packages to be installed, removed or upgraded). If you are familiar with Unix, you will probably want to at least glance through the Full listing for your favorite tools.

Once you have an existing Cygwin installation, the setup.exe chooser is also used to manage your Cygwin installation. Information on installed packages is kept in the /etc/setup/ directory of your Cygwin installation; if setup.exe cannot find this directory it will act as if you have no Cygwin installation. If setup.exe finds a newer version of an installed package available, it will automatically mark it to be upgraded. To Uninstall , Reinstall , or get the Source for an existing package, click on Keep to toggle it. Also, to avoid the need to reboot after upgrading, make sure to close all Cygwin windows and stop all Cygwin processes before setup.exe begins to install the upgraded package.

To avoid unintentionally upgrading, use the Pending view to see which packages have been marked for upgrading. If you don’t want to upgrade a package, click on the new version number to toggle it until it says Keep . All packages can be set to stay at the installed version by pressing the Keep button in the top right part of the chooser window.

A previous version of each package is usually available, in case downgrading is required to avoid a serious bug in the current version of the package. Packages also occasionally have testing (or «experimental») versions available. Previous and experimental versions can be chosen by clicking on the package’s New column until the required version appears.

All available experimental packages can be selected by pressing the Exp in the top right part of the chooser window. Be warned, however, that the next time you run setup.exe it will try to replace all old or experimental versions with the current version, unless told otherwise.

Download and Installation Progress

First, setup.exe will download all selected packages to the local directory chosen earlier. Before installing, setup.exe performs a checksum on each package. If the local directory is a slow medium (such as a network drive) this can take a long time. During the download and installation, setup.exe shows progress bars for the current task and total remaining disk space.

Shortcuts

You may choose to install «Cygwin Terminal» shortcuts on the Desktop and/or Start Menu. These shortcuts run mintty , which will start your default shell as specified in /etc/passwd .