Installation Instructions
*************************

Contents
========

There is only one recommended way to install Cygwin, which is to use the GUI installer ``Cygwin Setup''.  It is flexible and easy to use. You can pick and choose the packages you wish to install, and update them individually.  Full source code is available for all packages and tools.  More information on using Cygwin Setup may be found at http://cygwin.com/cygwin-ug-net/setup-net.html.

If you do it any other way, you're on your own!  That said, keep in mind that the GUI installer is a "work in progress", so there might be a few difficulties, especially if you are behind a firewall or have other specific requirements.  If something doesn't work right for you, and it's not covered here or in the latest development snapshot at http://cygwin.com/setup/, then by all means report it to the mailing list.

For a searchable list of packages that can be installed with Cygwin, see http://cygwin.com/packages/.

Installation using ``Cygwin Setup''
===================================

The Cygwin Setup program is the only recommended way to install Cygwin.

Why not install in C:\?
-----------------------

The Cygwin Setup program will prompt you for a "root" directory. The default is C:\cygwin, but you can change it.  You are urged not to choose something like C:\ (the root directory on the system drive) for your Cygwin root.  If you do, then critical Cygwin system directories like etc, lib and bin could easily be corrupted by other (non-Cygwin) applications or packages that use \etc, \lib or \bin.  Perhaps there is no conflict now, but who knows what you might install in the future?  It's also just good common sense to segregate your Cygwin "filesystems" from the rest of your Windows system disk.

(In the past, there had been genuine bugs that would cause problems for people who installed in C:\, but we believe those are gone now.)

Can I use Cygwin Setup to get old versions of packages (like gcc-2.95)?
-----------------------------------------------------------------------

Cygwin Setup can be used to install any packages that are on a Cygwin mirror, which usually includes one version previous to the current one. The complete list may be searched at http://cygwin.com/packages/.  There is no complete archive of older packages. If you have a problem with the current version of a Cygwin package, please report it to the mailing list using the guidelines at http://cygwin.com/problems.html.

That said, if you really need an older package, you may be able to find an outdated or archival mirror by searching the web for an old package version (for example, gcc2-2.95.3-10-src.tar.bz2), but keep in mind that this older version will not be supported by the mailing list and that installing the older version will not help improve Cygwin.

Is Cygwin Setup, or one of the packages, infected with a virus?
---------------------------------------------------------------

Unlikely.  Unless you can confirm it, please don't report it to the mailing list.  Anti-virus products have been known to detect false positives when extracting compressed tar archives.  If this causes problems for you, consider disabling your anti-virus software when running setup.  Read the next entry for a fairly safe way to do this.

My computer hangs when I run Cygwin Setup!
------------------------------------------

Both Network Associates (formerly McAfee) and Norton anti-virus products have been reported to "hang" when extracting Cygwin tar archives.  If this happens to you, consider disabling your anti-virus software when running Cygwin Setup.  The following procedure should be a fairly safe way to do that:

 1. Download setup.exe and scan it explicitly.

 2. Turn off the anti-virus software.

 3. Run setup to download and extract all the tar files.

 4. Re-activate your anti-virus software and scan everything in C:\cygwin (or wherever you chose to install), or your entire hard disk if you are paranoid.

This should be safe, but only if Cygwin Setup is not substituted by something malicious, and no mirror has been compromised.

What packages should I download? Where are 'make', 'gcc', 'vi', etc?
--------------------------------------------------------------------

When using Cygwin Setup for the first time, the default is to install a minimal subset of packages.  If you want anything beyond that, you will have to select it explicitly.  See http://cygwin.com/packages/ for a searchable list of available packages.

If you want to build programs, of course you'll need gcc, binutils, make and probably other packages from the ``Devel'' category. Text editors can be found under ``Editors''.

How do I just get everything?
-----------------------------

Long ago, the default was to install everything, much to the irritation of most users.  Now the default is to install only a basic core of packages.  Cygwin Setup is designed to make it easy to browse categories and select what you want to install or omit from those categories.  It's also easy to install everything:

 1. At the ``Select Packages'' screen, in ``Categories'' view, at the line marked ``All'', click on the word ``default'' so that it changes to ``install''.  (Be patient, there is some computing to do at this step. It may take a second or two to register the change.)  This tells Setup to install everything, not just what it thinks you should have by default.

 2. Now click on the ``View'' button (twice) until you get the ``Partial'' view.  This shows exactly which packages are about to be downloaded and installed.

This procedure only works for packages that are currently available. There is no way to tell Cygwin Setup to install all packages by default from now on.  As new packages become available that would not be installed by default, you have to repeat the above procedure to get them.

In general, a better method (in my opinion), is to:

 1. First download & install all packages that would normally be installed by default.  This includes fundamental packages and any updates to what you have already installed.  Then...

 2. Run Cygwin Setup again, and apply the above technique to get all new packages that would not be installed by default.  You can check the list in the Partial View before proceeding, in case there's something you really don't want.

 3. In the latest version of Cygwin Setup, if you click the ``View'' button (twice) more, it shows packages not currently installed.  You ought to check whether you really want to install everything!

How much disk space does Cygwin require?
----------------------------------------

That depends, obviously, on what you've chosen to download and install.  A full installation today is probably larger than 800MB installed, not including the package archives themselves nor the source code.

After installation, the package archives remain in your ``Local Package Directory'', by default the location of setup.exe.  You may conserve disk space by deleting the subdirectories there.  These directories will have very weird looking names, being encoded with their URLs.

What if setup fails?
--------------------

First, make sure that you are using the latest version of Cygwin Setup.  The latest version is always available from the 'Install Cygwin now' link on the Cygwin Home Page at http://cygwin.com/.

If you are downloading from the Internet, setup will fail if it cannot download the list of mirrors at http://cygwin.com/mirrors.html.  It could be that the network is too busy.  Something similar could be the cause of a download site not working.  Try another mirror, or try again later.

If setup refuses to download a package that you know needs to be upgraded, try deleting that package's entry from /etc/setup.  If you are reacting quickly to an announcement on the mailing list, it could be that the mirror you are using doesn't have the latest copy yet.  Try another mirror, or try again tomorrow.

If setup has otherwise behaved strangely, check the files setup.log and setup.log.full in /var/log (C:\cygwin\var\log by default).  It may provide some clues as to what went wrong and why.

If you're still baffled, search the Cygwin mailing list for clues. Others may have the same problem, and a solution may be posted there. If that search proves fruitless, send a query to the Cygwin mailing list.  You must provide complete details in your query: version of setup, options you selected, contents of setup.log and setup.log.full, what happened that wasn't supposed to happen, etc.

My Windows logon name has a space in it, will this cause problems?
------------------------------------------------------------------

Most definitely yes!  UNIX shells (and thus Cygwin) use the space character as a word delimiter.  Under certain circumstances, it is possible to get around this with various shell quoting mechanisms, but you are much better off if you can avoid the problem entirely.

On Windows NT/2000/XP you have two choices:

 1. You can rename the user in the Windows User Manager GUI and then run mkpasswd.

 2. You can simply edit the /etc/passwd file and change the Cygwin user name (first field). It's also a good idea to avoid spaces in the home directory.

On Windows 95/98/ME you can create a new user and run mkpasswd, or you can delete the offending entry from /etc/passwd. Cygwin will then use the name in the default entry with uid 500.

My HOME environment variable is not what I want.
------------------------------------------------

When starting Cygwin from Windows, HOME is determined as follows in order of decreasing priority:

 1. HOME from the Windows environment, translated to POSIX form.

 2. The entry in /etc/passwd

 3. HOMEDRIVE and HOMEPATH from the Windows environment

 4. /

When using Cygwin from the network (telnet, ssh,...), HOME is set from /etc/passwd.

If your HOME is set to a value such as /cygdrive/c, it is likely that it was set in Windows. Start a DOS Command Window and type "set HOME" to verify if this is the case.

Access to shared drives is often restricted when starting from the network, thus Domain users may wish to have a different HOME in the Windows environment (on shared drive) than in /etc/passwd (on local drive). Note that ssh only considers /etc/passwd, disregarding HOME.

How do I uninstall individual packages?
---------------------------------------

Run Cygwin Setup as you would to install packages.  In the list of packages to install, browse the relevant category or click on the ``View'' button to get a full listing.  Click on the cycle glyph until the action reads ``Uninstall''.  Proceed by clicking ``Next''.

How do I uninstall all of Cygwin?
---------------------------------

Setup has no automatic uninstall facility.  The recommended method to remove all of Cygwin is as follows:

 1. Remove all Cygwin services.  If a service is currently running, it must first be stopped with cygrunsrv -E name, where name is the name of the service.  Then use cygrunsrv -R name to uninstall the service from the registry.  Repeat this for all services that you installed. Common services that might have been installed are sshd, cron, cygserver, inetd, apache, and so on.

 2. Stop the X11 server if it is running, and terminate any Cygwin programs that might be running in the background.  Remove all mount information by typing umount -A and then exit the command prompt and ensure that no Cygwin processes remain.  Note: If you want to save your mount points for a later reinstall, first save the output of mount -m as described at http://cygwin.com/cygwin-ug-net/using-utils.html#mount.

 3. Delete the Cygwin root folder and all subfolders.  If you get an error that an object is in use, then ensure that you've stopped all services and closed all Cygwin programs.  If you get a 'Permission Denied' error then you will need to modify the permissions and/or ownership of the files or folders that are causing the error.  For example, sometimes files used by system services end up owned by the SYSTEM account and not writable by regular users.

     The quickest way to delete the entire tree if you run into this problem is to change the ownership of all files and folders to your account.  To do this in Windows Explorer, right click on the root Cygwin folder, choose Properties, then the Security tab.  Select Advanced, then go to the Owner tab and make sure your account is listed as the owner.  Select the 'Replace owner on subcontainers and objects' checkbox and press Ok.  After Explorer applies the changes you should be able to delete the entire tree in one operation.  Note that you can also achieve this in Cygwin by typing chown -R user / or by using other tools such as CACLS.EXE.

 4. Delete the Cygwin shortcuts on the Desktop and Start Menu, and anything left by setup.exe in the download directory.  However, if you plan to reinstall Cygwin it's a good idea to keep your setup.exe download directory since you can reinstall the packages left in its cache without redownloading them.

 5. If you added Cygwin to your system path, you should remove it unless you plan to reinstall Cygwin to the same location.  Similarly, if you set your CYGWIN environment variable system-wide and don't plan to reinstall, you should remove it.

 6. Finally, if you want to be thorough you can delete the registry tree Software\Cygnus Solutions under HKEY_LOCAL_MACHINE and/or HKEY_CURRENT_USER.  However, if you followed the directions above you will have already removed all the mount information which is typically the only thing stored in the registry.

How do I install snapshots?
---------------------------

First, are you sure you want to do this?  Snapshots are risky.  They have not been tested.  Use them only if there is a feature or bugfix that you need to try, and you are willing to deal with any problems.

Before installing a snapshot, you must first Close all Cygwin applications, including shells and services (e.g. inetd, sshd), before updating cygwin1.dll.  You may have to restart Windows to clear the DLL from memory.

You cannot use Setup to install a snapshot.

You should generally install the full cygwin-inst-YYYYMMDD.tar.bz2 update, rather than just the DLL, otherwise some components may be out of sync.  Cygwin tar won't be able to update /usr/bin/cygwin1.dll, but it should succeed with everything else.

 1. Download the snapshot, and run:

          	cd /
                  tar jxvf /posix/path/to/cygwin-inst-YYYYMMDD.tar.bz2 --exclude=usr/bin/cygwin1.dll
                  cd /tmp
                  tar jxvf /posix/path/to/cygwin-inst-YYYYMMDD.tar.bz2 usr/bin/cygwin1.dll

 2. After closing all Cygwin apps (see above), use Explorer or the Windows command shell to move C:\cygwin\tmp\usr\bin\cygwin1.dll to C:\cygwin\bin\cygwin1.dll.

Can Cygwin Setup maintain a ``mirror''?
---------------------------------------

NO.  Cygwin Setup cannot do this for you.  Use a tool designed for this purpose.  See http://rsync.samba.org/, http://wget.sunsite.dk/ for utilities that can do this for you. For more information on setting up a custom Cygwin package server, see the Cygwin Setup homepage at http://sources.redhat.com/cygwin-apps/setup.html.

How can I make my own portable Cygwin on CD?
--------------------------------------------

While some users have successfully done this, for example Indiana University's XLiveCD http://xlivecd.indiana.edu/, there is no easy way to do it. Full instructions for constructing a porttable Cygwin on CD by hand can be found on the mailing list at http://www.cygwin.com/ml/cygwin/2003-07/msg01117.html.  (Thanks to fergus at bonhard dot uklinux dot net for these instructions.)

How do I save, restore, delete, or modify the Cygwin information stored in the registry?
----------------------------------------------------------------------------------------

Currently Cygwin stores its mount table information in the registry.  It is recommended that you use the mount and umount commands to manipulate the mount information instead of directly modifying the registry.

To save the mount information to a file for later restoration, use mount -m > mounts.bat To remove all mount information use umount -A.  To reincorporate saved mount information just run the batch file. For more information on using mount, see http://cygwin.com/cygwin-ug-net/using-utils.html#mount.