Richard's Cygwin Tips
Cygwin is a free Unix/Linux-like (POSIX) environment for Windows. It
The official Cygwin home page is http://cygwin.com/.
- a DLL (cygwin1.dll) which acts as a Linux API emulation
- a collection of programs, config files, documentation,
etc., providing a Linux look-and-feel
- The MS-DOS/Windows console and command line shell is almost
there are few available console programs (with very ad hoc behaviour),
and there is no package management.
- The Unix world has much better consoles and shells, loads
standardized and very useful programs, and the Cygwin installer program
handles downloads and updates for you.
How does it work?
- It is not an emulator or
virtual machine - the programs
normal Win32 executables that just use the Cygwin DLL.
- The whole point of the Cygwin DLL is that programs written
Unix/Linux don't have to be rewritten in order to run under Windows.
- This means that huge amounts
of free/open source
Unix software is available also on Windows.
- However, the programs believe that they are running in
a Unix environment!
- By default, they assume that newlines are LF, not
CRLF, but this is
usually not a problem (see the
on the CR/LF issue for further info.
- For programs that are sensitive to newline
conventions, you should
keep DOS/Windows files separate from Cygwin/Unix files.
- You can use the dos2unix and unix2dos
commands to convert or normalize newlines in files.
- The programs see the Windows file system as if it was a
system, with Unix user/group permissions, etc.
- A Unix program compiled under Cygwin does not have
to understand MS-DOS drive letters. Instead of
"C:\...", it just sees a normal Unix-like path "/cygdrive/c/...".
- You can use the cygpath command
in scripts to convert between Unix- and Windows-style paths.
- Go to http://cygwin.com
and download the file setup.exe
- Save this file somewhere for future use and make a shortcut
You will run it later every time you want to update or add packages.
- Run the setup.exe program
once, without changing any settings
(except for possibly the install
directory). Keep all RECOMMENDED settings and
don't add or remove
- ftp.sunet.se is a good mirror if
you're in Sweden.
- Detailed setup help can be found here
- After installation, click one of the new icons to start a
check that things are working.
- Whenever you want to check for updates, just run the
setup.exe program again (without changing any
settings). If there are updated versions of packages you
already have, they will be automatically installed.
- If you want to add or remove packages, do the same thing,
the package tree and select/deselect packages as you like.
When you click the icon to start a Cygwin shell, it runs
C:\Cygwin\cygwin.bat (if you used C:\Cygwin
as the install directory).
You should edit this file to set up some things:
- Set the CYGWIN environment variable
to "ntsec" (if you have
NTFS partitions). Look here
for more details.
- Set the HOME environment variable to
the DOS path to your home directory. If you used
C:\Cygwin as install directory, then HOME
C:\Cygwin\home\username, but there is nothing
stopping you from changing this to somewhere else.
- You might want to specialize your PATH
settings for Cygwin shells. For example:
- Many "plain Windows" console programs don't work
if they are called from a Cygwin-shell; in particular, programs that
want to ask the user questions about password etc. tend to hang or not
print the question until you have pressed enter. There is more details
on this problem in the PuttyCyg
- Because of package dependencies, you may get
Cygwin-versions of languages like Perl, Python, Ruby, etc., that you
might already have
native Windows versions of. It can be tricky to make sure that you run
the right version at the right time. In general, don't try to run the
Windows versions of such languages from the Cygwin shell, but run them
from a normal Windows console instead.
- Although you might think it would be convenient to have
Cygwin utilities even when you're not in a Cygwin shell, by putting
C:/cygwin/bin in your global Windows PATH,
this may cause DLL conflicts where there are two types of
DLLs with the same name (tcl84.dll is a common
example), or just get you into trouble with having both a
Cygwin executable and a Windows executable with the same name (find.exe
is one example). The general advice is do not put
cygwin/bin in your Windows PATH!
to get the most common Unix tools as native Windows programs
instead, and put those in your Windows path.
A better console window
By default, Cygwin will use the standard Windows console to run the
command line interpreter in. Since this sucks in many ways, you should
The thing with rxvt is that it is really an X11 application, but it
also works on Windows without an X11 server running. Either way, you
can configure it in your
$HOME/.Xresources file; e.g., like this:
- Run setup.exe again, and just skip to
In the group shells, you should find rxvt:
"VT102 terminal emulator for
both X and Windows". Select this, and click Next to finish the
- Edit C:\Cygwin\cygwin.bat again, and
change the line that starts
bash (or whatever shell you use) to the
rxvt -e bash --login -i
rxvt.boldFont: Lucida Console-12
rxvt.font: Lucida Console-12
Configuring tab-completion etc.
The shell (bash) uses the GNU Readline library to
read lines of input. This is where the input
history, tab-completion, etc., is handled. You can configure it by
editing your $HOME/.inputrc file. Here is an
# These are for proper 8-bit characters (едц, etc.)
Run "man readline" for details and more options. An easy way of checking the control sequence generated by a keypress is to run the command "od -c" and type away. End by pressing Ctrl-d twice. Where the output says "033", use "\e" in the file.
set meta-flag on
set input-meta on
set output-meta on
set convert-meta off
# Just flash screen, don't beep
set bell-style visible
# Be case-insensitive (nice on Windows machines)
set completion-ignore-case on
# These are also nice for tab-completion
set completion-query-items 16
set mark-symlinked-directories on
set print-completions-horizontally on
set show-all-if-unmodified on
# Home Key
# End Key
# Ctrl-cursor right/left
# (change to end-of-line/beginning-of-line if you prefer)
# Alt-cursor right/left
# Page up/down for beginning/end of history
Starting an X server
An X server is useful for running GUI programs on remote Unix machines,
but have the windows pop up on your local screen instead.
First, you need to run the Cygwin
setup.exe program and install at least the
package xorg-x11-base (in the package group X11).
for detailed help.
After installation, the easiest way to start the X server
is probably by creating a shortcut to the file
shouldn't need to edit the
.bat file, but you might want to take a look
at it just to see what it is doing.
More details here.
Note that when the server is running, you can control it
through an icon in the Windows tray.
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