Why can't my application locate cygncurses-8.dll? or cygintl-3.dll? or cygreadline6.dll? or ...?
Well, something has gone wrong somehow...
To repair the damage, you must run Cygwin Setup again, and re-install the
package which provides the missing DLL package.
If you already installed the package at one point, Cygwin Setup won't
show the option to install the package by default. In the
``Select packages to install'' dialog, click on the Full/Part
button. This lists all packages, even those that are already
installed. Scroll down to locate the missing package, for instance
libncurses8. Click on the ``cycle'' glyph until it says
``Reinstall''. Continue with the installation.
For a detailed explanation of the general problem, and how to extend
it to other missing DLLs and identify their containing packages, see
http://cygwin.com/ml/cygwin/2002-01/msg01619.html.
Why is Cygwin suddenly so slow?
If suddenly every command takes a
very long time, then something is probably attempting to
access a network share. You may have the obsolete //c
notation in your PATH or startup files. Using //c means
to contact the network server c, which
will slow things down tremendously if it does not exist.
Using //c (for C:) doesn't work. (Similarly for any drive
letter, e.g. //z for Z:) This
``feature'' has long been deprecated.
For a detailed discussion of why this change was made, and how deal
with it, refer to
http://sources.redhat.com/ml/cygwin/2001-09/msg00014.html.
Just note that, in contrast to what that posting claims, using
/ as the cygdrive prefix is not supported anymore for a
long time (though it still might work).
Why can't my services access network shares?
If your service is one of those which switch the user context
(sshd, inetd, etc), then it depends on the method used to switch to
another user. This problem as well as its solution is described in
detail in the Cygwin User's Guide, see
.
Workarounds include using public network share that does not require
authentication (for non-critical files), providing your password to a
net use command, or running the service as your own
user with cygrunsrv -u (see
/usr/share/doc/Cygwin/cygrunsrv.README for more
information).
How should I set my PATH?
This is done for you in the file /etc/profile, which is sourced by bash
when you start it from the Desktop or Start Menu shortcut, created by
setup.exe. The line is
PATH="/usr/local/bin:/usr/bin:/bin:$PATH"
Effectively, this prepends /usr/local/bin and /usr/bin to your
Windows system path. If you choose to reset your PATH, say in
$HOME/.bashrc, or by editing etc/profile directly, then you should
follow this rule. You must have /usr/bin in your PATH
before any Windows system directories. (And you must not omit
the Windows system directories!) Otherwise you will likely encounter
all sorts of problems running Cygwin applications.
If you're using another shell than bash (say, tcsh), the mechanism
is the same, just the names of the login scripts are different.
Bash (or another shell) says "command not found", but it's right there!
If you compile a program, you might find that you can't run it:
bash$ gcc -o hello hello.c
bash$ hello
bash: hello: command not found
Unlike the Windows default behaviour, Unix shells like bash do not look for programs in . (the current
directory) by default. You can add . to your PATH (see above),
but this is not recommended (at least on UNIX) for security reasons.
Just tell bash where to find it, when you type it on the command line:
bash$ gcc -o hello hello.c
bash$ ./hello
Hello World!
How do I convert between Windows and UNIX paths?
Use the 'cygpath' utility. Type 'cygpath --help' for
information. For example (on my installation):
bash$ cygpath --windows ~/.bashrc
D:\starksb\.bashrc
bash$ cygpath --unix C:/cygwin/bin/cygwin.bat
/usr/bin/cygwin.bat
bash$ cygpath --unix C:\\cygwin\\bin\\cygwin.bat
/usr/bin/cygwin.bat
Note that bash interprets the backslash '\' as an escape character, so
you must type it twice in the bash shell if you want it to be recognized
as such.
Why doesn't bash read my .bashrc file on startup?
Your .bashrc is read from your home directory specified by the HOME
environment variable. It uses /.bashrc if HOME is not set. So you need
to set HOME (and the home dir in your /etc/passwd entry) correctly.
How can I get bash filename completion to be case insensitive?
Add the following to your ~/.bashrc file:
shopt -s nocaseglob
and add the following to your ~/.inputrc file:
set completion-ignore-case on
Can I use paths/filenames containing spaces in them?
Cygwin does support spaces in filenames and paths. That said, some
utilities that use the library may not, since files don't typically
contain spaces in Unix. If you stumble into problems with this, you
will need to either fix the utilities or stop using spaces in filenames
used by Cygwin tools.
In particular, bash interprets space as a word separator. You would have
to quote a filename containing spaces, or escape the space character.
For example:
bash-2.03$ cd '/cygdrive/c/Program Files'
or
bash-2.03$ cd /cygdrive/c/Program\ Files
Why can't I cd into a shortcut to a directory?
Cygwin does not follow MS Windows Explorer Shortcuts
(*.lnk files). It sees a shortcut as a regular file and this you
cannot "cd" into it.
Cygwin is also capable to create POSIX symlinks as Windows shortcuts
(see the CYGWIN environment variable option "winsymlinks"), but these
shortcuts are different from shortcuts created by native Windows
applications. Windows applications can usually make use of Cygwin
shortcuts but not vice versa. This is by choice. The reason is that
Windows shortcuts may contain a bunch of extra information which would
get lost, if, for example, Cygwin tar archives and extracts them as
symlinks.
Changing a Cygwin shortcut in Windows Explorer usually changes a Cygwin
shortcut into a Windows native shortcut. Afterwards, Cygwin will not
recognize it as symlink anymore.
I'm having basic problems with find. Why?
Make sure you are using the find that came with Cygwin and that you
aren't picking up the Win32 find command instead. You can verify that
you are getting the right one by doing a "type find" in bash.
If the path argument to find, including current directory (default), is
itself a symbolic link, then find will not traverse it unless you
specify the -follow option. This behavior is different than most
other UNIX implementations, but is not likely to change.
If find does not seem to be producing enough results, or seems to be
missing out some directories, you may be experiencing a problem with one
of find's optimisations. The absence of . and ..
directories on some filesystems, such as DVD-R UDF, can confuse find.
See the documentation for the option -noleaf in the man page.
Why doesn't su work?
The su command has been in and out of Cygwin distributions, but
it has not been ported to Cygwin and has never worked. It is
currently installed as part of the sh-utils, but again, it does not work.
You should rather install sshd and use
ssh username@localhost as a su
replacement.
For some technical background into why su doesn't work, read
http://www.cygwin.com/ml/cygwin/2003-06/msg00897.html and
related messages.
Why doesn't man -k (or apropos) work?
Before you can use man -k or apropos, you
must create the whatis database. Just run the command
/usr/sbin/makewhatis
(it may take a minute to complete).
Why doesn't chmod work?
The most common case is that your /etc/passwd
or /etc/group files are not properly set up. If
ls -l shows a group of mkpasswd
or mkgroup, you need to run one or both of those
commands.
If you're using FAT32 instead of NTFS, chmod
will fail since FAT32 does not provide any permission information.
You should really consider converting the drive to NTFS with
CONVERT.EXE. FAT and FAT32 are barely good enough
for memory cards or USB sticks to exchange pictures...
For other cases, understand that Cygwin attempts to show UNIX
permissions based on the security features of Windows, so the Windows
ACLs are likely the source of your problem. See the Cygwin User's
Guide at
for more information on how Cygwin maps Windows permissions.
Why doesn't my shell script work?
There are two basic problems you might run into. One is the fact that
/bin/sh is really bash.
It could be missing some features you might expect in
/bin/sh, if you are used to /bin/sh
actually being zsh (MacOS X "Panther") or
ksh (Tru64).
Or, it could be a permission problem, and Cygwin doesn't understand
that your script is executable. On NTFS or NFS just make the script
executable using chmod +x. However,
chmod may not work due to restrictions of the
filesystem (see FAQ entry above). In this case Cygwin must read the
contents of files to determine if they are executable. If your script
does not start with
#! /bin/sh
(or any path to a script interpreter, it does not have to be /bin/sh)
then Cygwin will not know it is an executable script. The Bourne shell
idiom
:
# This is the 2nd line, assume processing by /bin/sh
also works.
Note that you can use the filesystem flag cygexec in
/etc/fstab to force Cygwin to treat all files
under the mount point as executable. This can be used for individual
files as well as directories. Then Cygwin will not bother to read files
to determine whether they are executable.
How do I print under Cygwin?
lpr is available in the setup.exe cygutils package. Some usage hints are available courtesy of Rodrigo Medina.
Jason Tishler has written a couple of messages that explain how to use
a2ps (for nicely formatted text in PostScript) and ghostscript (to print
PostScript files on non-PostScript Windows printers). Start at
http://cygwin.com/ml/cygwin/2001-04/msg00657.html. Note that the
file command is now available as part of Cygwin setup.
Alternatively, on NT, you can use the Windows print
command. (It does not seem to be available on Win9x.) Type
bash$ print /\?
for usage instructions (note the ? must be escaped from the
shell).
Finally, you can simply cat the file to the printer's share name:
bash$ cat myfile > //host/printer
You may need to press the formfeed button on your printer or append the
formfeed character to your file.
Why don't international (Unicode) characters work?
Internationalization is a complex issue. The short answer is that
Cygwin relies on the setting of the setting of LANG/LC_xxx environment
variables. The long answer can be found in the User's Guide in the
section Internationalization
To get UTF-8 support you must set the LANG, LC_ALL, or LC_CTYPE
environment variables. To get UTF-8 support you can set, for instance,
$LANG to "en_US.UTF-8". This will give you support for the UTF-8 character
set. Note that the language part has to contain a valid language specifier,
but is otherwise so far ignored. There's no support for correct
language-specific collation, monetary or date/time-related
string handling. This is planned for a later release, though.
To type international characters (£äö) in
bash, check if the following settings are available in
your bash, and if not, add them to your
~/.inputrc file and restart bash:
set meta-flag on
set convert-meta off
set output-meta on
set input-meta on
These are options to the readline library, which
you can read about in the bash(1) and
readline(3) man pages. Other tools that do not use
readline for display, such as less
and ls, might require additional settings for doublebyte
or multibyte charsets, which could be put
in your ~/.bashrc, for instance:
alias less='/bin/less -r'
alias ls='/bin/ls -F --color=tty --show-control-chars'
My application prints international characters but I only
see gray boxes
Very likely you didn't set your Console character set to the preferred
character set before the first Cygwin application was started in the
console. To make sure the console is using the desired character set,
maile sure that one of the internationalization environment variables
LC_ALL, LC_CTYPE, or LANG is set before the first Cygwin process starts.
You can do that, for instance, by setting the variable in your
Cygwin.bat file from which you start your Cygwin shell.
For a more detailed explanation see the section
The Windows Console character set in the Cygwin User's Guide.
Is it OK to have multiple copies of the DLL?
You should only have one copy of the Cygwin DLL on your system. If you
have multiple versions, they will conflict and cause problems.
If you get the error "shared region is corrupted" or "shared region
version mismatch" it means you have multiple versions of cygwin1.dll
running at the same time which conflict with each other. This could happen,
for example, if you update cygwin1.dll without exiting
all Cygwin apps (including inetd) beforehand.
The only DLL that is sanctioned by the Cygwin project is the one that
you get by running setup.exe,
installed in the directory controlled by this program. If you have other
versions on your system and desire help from the cygwin project, you should
delete or rename all DLLs that are not installed by
setup.exe.
If you're trying to find multiple versions of the DLL that are causing
this problem, reboot first, in case DLLs still loaded in memory are the
cause. Then use the Windows System find utility to search your whole
machine, not just components in your PATH (as 'type' would do) or
cygwin-mounted filesystems (as Cygwin 'find' would do).
I read the above but I want to bundle Cygwin with a product, and ship it
to customer sites. How can I do this without conflicting with any
Cygwin installed by the user?
Third party developers who wish to use Cygwin should check if
there is a version of cygwin installed and use the installed
version if it is newer, or conditionally upgrade if it is not.
(If you write a tool to make this easy, consider contributing
it for others to use)
Can I bundle Cygwin with my product for free?
Only if you comply with Cygwin's license very carefully. If you
choose to distribute cygwin1.dll, you must be willing to distribute the
exact source code used to build that copy of cygwin1.dll as per the
terms of the GPL. If you ship applications that link with cygwin1.dll,
you must either provide those applications' source code under a
GPL-compatible license, *or* purchase a cygwin license from Red Hat.
So I can't install a private version of the Cygwin DLL without
conflicting with the system cygwin?
Actually, if you are very careful, you can have two different versions
of the Cygwin DLL installed on your system at the same time but they
must be run serially. The only exception from this rule is, if one of
the DLLs is a pre-1.7 DLL and the other is a 1.7.0 or later DLL. These
DLLs can work concurrently without knowing about each other due to
massive changes using shared resources in Cygwin 1.7. However,
processes using different DLLs will not interact with each other
correctly, so keep them separate except you really really know what
you're doing.
This usage is not recommeded for novices. Only limited support will be
provided in the mailing lists
if you run into problems.
But doesn't that mean that if some application installs an older Cygwin
DLL on top of a newer DLL, my application will break?
It depends on what you mean by "break". If the application installs a
version of the Cygwin DLL in another location than Cygwin's /bin
directory then the rules in
apply.
If the application installs an older version of the DLL in /bin then you
should complain loudly to the application provider.
Remember that the Cygwin DLL strives to be backwards compatible so a
newer version of the DLL should always work with older executables. So,
in general, it is always best to keep one version of the DLL on your
system and it should always be the latest version which matches your
installed distribution.
Why isn't package XYZ available in Cygwin?
Probably because there is nobody willing or able to maintain it. It
takes time, and the priority for the Cygwin Team is the Cygwin package.
The rest is a volunteer effort. Want to contribute? See
http://cygwin.com/setup.html.
Why is the Cygwin package of XYZ so out of date?
(Also: Why is the version of package XYZ older than the version that I
can download from the XYZ web site? Why is the version of package XYZ
older than the version that I installed on my linux system? Is there
something special about Cygwin which requires that only an older version
of package XYZ will work on it?)
Every package in the Cygwin distribution has a maintainer who is
responsible for sending out updates of the package. This person is a
volunteer who is rarely the same person as the official developer of the
package. If you notice that a version of a package seems to be out of
date, the reason is usually pretty simple -- the person who is
maintaining the package hasn't gotten around to updating it yet. Rarely,
the newer package actually requires complex changes that the maintainer
is working out.
If you urgently need an update, sending a polite message to the cygwin
mailing list pinging the maintainer is perfectly acceptable. There are
no guarantees that the maintainer will have time to update the package
or that you'll receive a response to your request, however.
Remember that the operative term here is "volunteer".
How can I access other drives?
You have some flexibility here.
Cygwin has a builtin "cygdrive prefix" for drives that are not mounted.
You can access any drive, say Z:, as '/cygdrive/z/'.
In some applications (notably bash), you can use the familiar windows
<drive>:/path/, using posix forward-slashes ('/') instead of Windows
backward-slashes ('\'). (But see the warning below!) This maps in the
obvious way to the Windows path, but will be converted internally to use
the Cygwin path, following mounts (default or explicit). For example:
bash$ cd C:/Windows
bash$ pwd
/cygdrive/c/Windows
and
bash$ cd C:/cygwin
bash$ pwd
/
for a default setup. You could also use backward-slashes in the
Windows path, but these would have to be escaped from the shell.
Warning: There is some ambiguity in going from a Windows path
to the posix path, because different posix paths, through different
mount points, could map to the same Windows directory. This matters
because different mount points may be binmode or textmode, so the
behavior of Cygwin apps will vary depending on the posix path used to
get there.
You can avoid the ambiguity of Windows paths, and avoid typing
"/cygdrive", by explicitly mounting drives to posix paths. For example:
bash$ mkdir /c
bash$ mount c:/ /c
bash$ ls /c
Then /cygdrive/c/Windows becomes /c/Windows which is a
little less typing.
Note that you have to enter the mount point into the
/etc/fstab file to keep it indefinitely.
The mount command will only add the mount point for the lifetime
of your current Cygwin session.
You can change the default cygdrive prefix and whether it is binmode or textmode using the /etc/fstab file
as well. See the Cygwin User's Guide at
http://cygwin.com/1.7/cygwin-ug-net/using.html#mount-table
for more details.
How can I copy and paste into Cygwin console windows?
First, consider using rxvt or mintty instead of the standard console
window. In rxvt/mintty, selecting with the left-mouse also copies,
and middle-mouse pastes. It couldn't be easier!
In Windows's console window, open the properties dialog.
The options contain a toggle button, named "Quick edit mode". It must
be ON. Save the properties.
You can also bind the insert key to paste from the clipboard by adding
the following line to your .inputrc file:
"\e[2~": paste-from-clipboard
What firewall should I use with Cygwin?
We have had good reports about Kerio Personal Firewall, ZoneLabs
Integrity Desktop, and the built-in firewall in Windows XP. Other
well-known products including ZoneAlarm and Norton Internet Security have
caused problems for some users but work fine for others. At last report,
Agnitum Outpost did not work with Cygwin. If you are having strange
connection-related problems, disabling the firewall is a good
troubleshooting step (as is closing or disabling all other running
applications, especially resource-intensive processes such as indexed
search).
On the whole, Cygwin doesn't care which firewall is used. The few rare
exceptions have to do with socket code.
Cygwin uses sockets to implement many of its functions, such as IPC.
Some overzealous firewalls install themselves deeply into the winsock
stack (with the 'layered service provider' API) and install hooks
throughout. Sadly the mailing list archives are littered with examples
of poorly written firewall-type software that causes things to break.
Note that with many of these products, simply disabling the firewall
does not remove these changes; it must be completely uninstalled.
See also
for a list of applications that have been known, at one time or another, to
interfere with the normal functioning of Cygwin.
How can I share files between Unix and Windows?
During development, we have Linux boxes running Samba and NFS as well
as Windows machines. We often build with cross-compilers under Linux and copy
binaries and source to the Windows system or just toy with them
directly off the Samba-mounted partition. Or, we use the Microsoft NFS
client and just use NFS shares on Linux from Windows. And then there are
tools like scp, ftp,
rsync, ...
Is Cygwin case-sensitive??
Several Unix programs expect to be able to use to filenames
spelled the same way, but with different case. A prime example
of this is perl's configuration script, which wants
Makefile and makefile. Windows can't
tell the difference between files with just different case, so the
configuration fails.
To help with this problem, Cygwin supports casesensitivity
starting with Cygwin 1.7.0. For a detailed description how to use that
feature see the Cygwin User's Guilde at
http://cygwin.com/1.7/cygwin-ug-net/using-specialnames.html.
What about DOS special filenames?
In Windows, files cannot be named com1, lpt1, or aux (to name a few);
either as the root filename or as the extension part. If you do, you'll have
trouble. Unix programs don't avoid these names which can make things
interesting. E.g., the perl distribution has a file called
aux.sh. The perl configuration tries to make sure that
aux.sh is there, but an operation on a file with the magic
letters 'aux' in it will hang.
At least that's what happens when using native Windows tools. Cygwin
1.7.0 and later can deal with these filenames just fine. Again, see the
User's Guide at
http://cygwin.com/1.7/cygwin-ug-net/using-specialnames.html
for a detailed description of what's possible with filenames and what is not.
When it hangs, how do I get it back?
If something goes wrong and the tools hang on you for some reason (easy
to do if you try and read a file called aux.sh), first try hitting ^C to
return to bash or the cmd prompt.
If you start up another shell, and applications don't run, it's a good
bet that the hung process is still running somewhere. Use the Task
Manager, pview, or a similar utility to kill the process.
And, if all else fails, there's always the reset button/power switch.
In theory this should never be necessary, though.
Why the weird directory structure?
Why do /lib and /usr/lib (and /bin, /usr/bin) point to the same thing?
Why use mounts instead of symbolic links?
Can I use a disk root (e.g., C:\) as Cygwin root? Why is this discouraged?
After a new installation in the default location, your mount points will
look something like this:
bash$ mount
C:\cygwin\bin on /usr/bin type system (binmode)
C:\cygwin\lib on /usr/lib type system (binmode)
C:\cygwin on / type system (binmode)
(Exactly what you see depends on what options you gave to setup.exe.)
Note that /bin and /usr/bin point to the same location, as do /lib and
/usr/lib. This is intentional, and you should not undo these mounts
unless you really know what you are doing.
Various applications and packages may expect to be installed in /lib or
/usr/lib (similarly /bin or /usr/bin). Rather than distinguish between
them and try to keep track of them (possibly requiring the occasional
duplication or symbolic link), it was decided to maintain only one
actual directory, with equivalent ways to access it.
Symbolic links had been considered for this purpose, but were dismissed
because they do not always work on Samba drives. Also, mounts are
faster to process because no disk access is required to resolve them.
Note that non-cygwin applications will not observe Cygwin mounts (or
symlinks for that matter). For example, if you use WinZip to unpack the
tar distribution of a Cygwin package, it may not get installed to the
correct Cygwin path. So don't do this!
It is strongly recommended not to make the Cygwin root directory the
same as your drive's root directory, unless you know what you are doing
and are prepared to deal with the consequences. It is generally easier
to maintain the Cygwin hierarchy if it is isolated from, say, C:\. For
one thing, you avoid possible collisions with other (non-cygwin)
applications that may create (for example) \bin and \lib directories.
(Maybe you have nothing like that installed now, but who knows about
things you might add in the future?)
How do anti-virus programs like Cygwin?
Users have reported that NAI (formerly McAfee) VirusScan for NT (and
others?) is incompatible with Cygwin. This is because it tries to scan
the newly loaded shared memory in cygwin1.dll, which can cause fork() to
fail, wreaking havoc on many of the tools. (It is not confirmed that
this is still a problem, however.)
There have been several reports of NAI VirusScan causing the system to
hang when unpacking tar.gz archives. This is surely a bug in VirusScan,
and should be reported to NAI. The only workaround is to disable
VirusScan when accessing these files. This can be an issue during
setup, and is discussed in that FAQ entry.
Some users report a significant performance hit using Cygwin when their
anti-virus software is enabled. Rather than disable the anti-virus
software completely, it may be possible to specify directories whose
contents are exempt from scanning. In a default installation, this
would be C:\cygwin\bin. Obviously, this could be
exploited by a hostile non-Cygwin program, so do this at your own risk.
See also
for a list of applications that have been known, at one time or another, to
interfere with the normal functioning of Cygwin.
Is there a Cygwin port of GNU Emacs?
Yes. It uses the X11 (http://cygwin.com/xfree/) GUI. Right now the package is old and outdated.
Consider using XEmacs for now.
Is there a Cygwin port of XEmacs?
Yes. It can be used in three different modes:
X11 (http://cygwin.com/xfree/) GUI
You have to set the DISPLAY environment variable
before starting xemacs.
bash$ DISPLAY=127.0.0.1:0 xemacs &
Windows native GUI
You have to unset the DISPLAY environment variable
before starting xemacs.
bash$ DISPLAY= xemacs &
Console mode
Start xemacs with -nw in a terminal (native or X11) window
bash$ xemacs -nw
The current stable Cygwin version of XEmacs is 21.4.x. But there is also a
Cygwin test release version (21.5.x) available for download via setup.exe.
To use all the standard packages with XEmacs you should download the following
two packages:
xemacs-sumo - XEmacs standard packages
xemacs-mule-sumo - XEmacs MULE (MUlti Lingual Emacs) packages
An alternative native distribution of XEmacs for
Windows based systems can be downloaded from
http://xemacs.org/Download/win32/index.html.
It uses an InnoSetup Kit based installer.
What about NT Emacs?
If you want GNU Emacs with a native Microsoft GUI interface,
then you can either use XEmacs (see above), or native
NT Emacs: see section
Where can I get pre-compiled versions? in NT Emacs FAQ.
NT Emacs uses the Windows command shell by default. Since it is not a
Cygwin application, it has no knowledge of Cygwin mounts. With those
points in mind, you need to add the following code to your ~/.emacs
(or ~/_emacs) file in order to use Cygwin bash. This is particularly useful
for the JDEE package (http://jdee.sunsite.dk/). The following
settings are for Emacs 21.1:
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Initial setup
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This assumes that Cygwin is installed in C:\cygwin (the
;; default) and that C:\cygwin\bin is not already in your
;; Windows Path (it generally should not be).
(setq exec-path (cons "C:/cygwin/bin" exec-path))
(setenv "PATH" (concat "C:\\cygwin\\bin;" (getenv "PATH")))
;; LOGNAME and USER are expected in many Emacs packages
;; Check these environment variables.
(if (and (null (getenv "USER"))
;; Windows includes variable USERNAME, which is copied to
;; LOGNAME and USER respectively.
(getenv "USERNAME"))
(setenv "USER" (getenv "USERNAME")))
(if (and (getenv "LOGNAME")
;; Bash shell defines only LOGNAME
(null (getenv "USER")))
(setenv "USER" (getenv "LOGNAME")))
(if (and (getenv "USER")
(null (getenv "LOGNAME")))
(setenv "LOGNAME" (getenv "USER")))
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; (A) M-x shell: This change M-x shell permanently
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Would call Windows command interpreter. Change it.
(setq shell-file-name "bash")
(setenv "SHELL" shell-file-name)
(setq explicit-shell-file-name shell-file-name)
;; Remove C-m (^M) characters that appear in output
(add-hook 'comint-output-filter-functions
'comint-strip-ctrl-m)
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; (B) *OR* call following function with M-x my-bash
;; The M-x shell would continue to run standard Windows shell
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun my-bash (&optional buffer)
"Run Cygwin Bash shell in optional BUFFER; default *shell-bash*."
(autoload 'comint-check-proc "comint")
(interactive
(let ((name "*shell-bash*"))
(if current-prefix-arg
(setq name (read-string
(format "Cygwin shell buffer (default %s): " name)
(not 'initial-input)
(not 'history)
name)))
(list name)))
(or buffer
(setq buffer "*shell-bash*"))
(if (comint-check-proc buffer)
(pop-to-buffer buffer)
(let* ((shell-file-name "bash")
(explicit-shell-file-name shell-file-name)
(explicit-sh-args '("--login" "-i"))
(explicit-bash-args explicit-sh-args)
(w32-quote-process-args ?\"));; Use Cygwin quoting rules.
(shell buffer)
;; By default Emacs sends "\r\n", but bash wants plain "\n"
(set-buffer-process-coding-system 'undecided-dos 'undecided-unix)
;; With TAB completion, add slash path separator, none to filenames
(make-local-variable 'comint-completion-addsuffix)
(setq comint-completion-addsuffix '("/" . ""))
;; This variable is local to buffer
(setq comint-prompt-regexp "^[ \n\t]*[$] ?"))))
If you want NT Emacs to understand Cygwin paths, get
cygwin-mount.el from http://www.emacswiki.org/elisp/index.html.
Note that all of this ``just works'' if you use the Cygwin port of
Emacs or XEmacs from Cygwin Setup.
Is there a better alternative to the standard console window?
Yes! Use rxvt or mintty instead. Both are optional packages in
Cygwin Setup. You can use rxvt with or without X11, while mintty is a
Cygwin application providing a native GUI.
Why do some of my old symlinks don't work anymore?
Beginning with Cygwin 1.7, Cygwin supports multiple character sets.
Symlinks created with Cygwin 1.7 are using the UTF-16 character set, which is
portable across all character sets. Old symlinks were written using your
current Windows codepage, which is not portable across all character sets.
If the target of the symlink doesn't resolve anymore, it's very likely that
the symlink points to a target filename using native, non-ASCII characters,
and you're now using another character set than way back when you created
the symlink.
Solution: Delete the symlink and create it again under you new Cygwin.
The new symlink will be correctly point to the target no matter what character
set you're using in future.
Why don't symlinks work on samba-mounted filesystems?
Symlinks are marked with "system" file attribute. Samba does not
enable this attribute by default. To enable it, consult your Samba
documentation and then add these lines to your samba configuration
file:
map system = yes
create mask = 0775
Note that the 0775 can be anything as long as the 0010 bit is set.
Alternatively, use Windows shortcuts as symlinks. See the CYGWIN
environment variable option "winsymlinks"
http://cygwin.com/1.7/cygwin-ug-net/using-cygwinenv.html
Why doesn't Cygwin tcl/tk understand Cygwin paths?
The versions of Tcl/Tk distributed with Cygwin (e.g. cygtclsh80.exe,
cygwish80.exe) are not actually "Cygwin versions" of those tools.
They are built as native libraries, which means they do not understand
Cygwin mounts or symbolic links.
See the entry "How do I convert between Windows and UNIX paths?"
elsewhere in this FAQ.
Why do I get "Address family not supported" errors when playing with IPv6?
IPv6 is fully supported and available right from the start with
Windows Vista and Windows Server 2008.
The previous generation of Windows,
Windows XP and Windows Server 2003, only support IPv6 on an "experimental"
basis. On these Windows versions, the IPv6 TCP/IP stack is not installed
automatically, rather the system administrator has to install it manually.
Unless this has already been done on your machine, your machine is not
IPv6-capable and that's why you see the "Address family not supported"
error message.
There's also a very experimental IPv6 stack for Windows 2000, and
Cygwin will try its best to support it, but it's not recommended to install
it. Windows NT4 or older never saw IPv6 at all.
For more information about IPv6 on Windows and how to install the
IPv6 stack, see the Microsoft TechNet IPv6 FAQ article
What applications have been found to interfere with Cygwin?
From time to time, people have reported strange failures and problems in
Cygwin and Cygwin packages that seem to have no rational explanation. Among
the most common symptoms they report are fork failures, memory leaks, and file
access denied problems. These problems, when they have been traced, often appear
to be caused by interference from other software installed on the same PC. Security
software, in particular, such as anti-virus, anti-spyware, and firewall applications,
often implements its functions by installing hooks into various parts of the system,
including both the Explorer shell and the underlying kernel. Sometimes these hooks
are not implemented in an entirely transparent fashion, and cause changes in the
behaviour which affect the operation of other programs, such as Cygwin.
Among the software that has been found to cause difficulties are:
Sonic Solutions burning software containing DLA component (when DLA disabled)
Norton/MacAfee/Symantec antivirus or antispyware
Logitech webcam software with "Logitech process monitor" service
Kerio, Agnitum or ZoneAlarm Personal Firewall
Iolo System Mechanic/AntiVirus/Firewall
LanDesk
Windows Defender
Embassy Trust Suite fingerprint reader software wxvault.dll
NOD32 Antivirus
ByteMobile laptop optimization client
Earthlink Total-Access
Spybot S&D TeaTimer
AR Soft RAM Disk
ATI Catalyst drivers
Windows LiveOneCare
Webroot Spy Sweeper with Antivirus
COMODO Firewall Pro
PC Tools Spyware Doctor
Avira AntiVir
Panda Internet Security
BitDefender
Google Desktop
Sophos Anti-Virus 7
Bufferzone from Trustware
Sometimes these problems can be worked around, by temporarily or partially
disabling the offending software. For instance, it may be possible to disable
on-access scanning in your antivirus, or configure it to ignore files under the
Cygwin installation root. Often, unfortunately, this is not possible; even disabling
the software may not work, since many applications that hook the operating system
leave their hooks installed when disabled, and simply set them into what is intended
to be a completely transparent pass-through mode. Sometimes this pass-through is not
as transparent as all that, and the hooks still interfere with Cygwin; in these cases,
it may be necessary to uninstall the software altogether to restore normal operation.
Some of the symptoms you may experience are:
Random fork() failures.
Caused by hook DLLs that load themselves into every process in the
system. POSIX fork() semantics require that the memory map of the child process
must be an exact duplicate of the parent process' layout. If one of these DLLs
loads itself at a different base address in the child's memory space as compared
to the address it was loaded at in the parent, it can end up taking the space that
belonged to a different DLL in the parent. When Cygwin can't load the original
DLL at that same address in the child, the fork() call has to fail.
File access problems.
Some programs (e.g., virus scanners with on-access scanning) scan or
otherwise operate on every file accessed by all the other software running on
your computer. In some cases they may retain an open handle on the file even
after the software that is really using the file has closed it. This has been
known to cause operations such as deletes, renames and moves to fail with
access denied errors. In extreme cases it has been known for scanners to leak
file handles, leading to kernel memory starvation.
Networking issues
Firewall software sometimes gets a bit funny about Cygwin. It's not
currently understood why; Cygwin only uses the standard Winsock2 API, but
perhaps in some less-commonly used fashion that doesn't get as well tested
by the publishers of firewalls. Symptoms include mysterious failures to
connect, or corruption of network data being sent or received.
Memory and/or handle leaks
Some applications that hook into the Windows operating system exhibit
bugs when interacting with Cygwin that cause them to leak allocated memory
or other system resources. Symptoms include complaints about out-of-memory
errors and even virtual memory exhaustion dialog boxes from the O/S; it is
often possible to see the excess memory allocation using a tool such as
Task Manager or Sysinternals' Process Explorer, although interpreting the
statistics they present is not always straightforward owing to complications
such as virtual memory paging and file caching.