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diff --git a/winsup/doc/faq-using.xml b/winsup/doc/faq-using.xml deleted file mode 100644 index 19e381624..000000000 --- a/winsup/doc/faq-using.xml +++ /dev/null @@ -1,1249 +0,0 @@ -<?xml version="1.0" encoding='UTF-8'?> -<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V4.5//EN" - "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"> - -<qandadiv id="faq.using"> -<title>Using Cygwin</title> - -<!-- faq-problems.xml --> -<qandaentry id="faq.using.missing-dlls"> -<question><para>Why can't my application locate cygncurses-8.dll? or cygintl-3.dll? or cygreadline6.dll? or ...?</para></question> -<answer> - -<para>Well, something has gone wrong somehow... -</para> -<para>To repair the damage, you must run Cygwin Setup again, and re-install the -package which provides the missing DLL package. -</para> -<para>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 <literal>Full/Part</literal> -button. This lists all packages, even those that are already -installed. Scroll down to locate the missing package, for instance -<literal>libncurses8</literal>. Click on the ``cycle'' glyph until it says -``Reinstall''. Continue with the installation. -</para> -<para>For a detailed explanation of the general problem, and how to extend -it to other missing DLLs and identify their containing packages, see -<ulink url="http://cygwin.com/ml/cygwin/2002-01/msg01619.html">http://cygwin.com/ml/cygwin/2002-01/msg01619.html</ulink>. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.slow"> -<question><para>Why is Cygwin suddenly <emphasis>so</emphasis> slow?</para></question> -<answer> - -<para>If suddenly <emphasis>every</emphasis> command takes a -<emphasis>very</emphasis> long time, then something is probably attempting to -access a network share. You may have the obsolete <literal>//c</literal> -notation in your PATH or startup files. Using <literal>//c</literal> means -to contact the <emphasis>network server</emphasis> <literal>c</literal>, which -will slow things down tremendously if it does not exist. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.shares"> -<question><para>Why can't my services access network shares?</para></question> -<answer> - -<para>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 -<ulink url="http://cygwin.com/cygwin-ug-net/ntsec.html" />. -</para> -<para>Workarounds include using public network share that does not require -authentication (for non-critical files), providing your password to a -<command>net use</command> command, or running the service as your own -user with <literal>cygrunsrv -u</literal> (see -<literal>/usr/share/doc/Cygwin/cygrunsrv.README</literal> for more -information). -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.path"> -<question><para>How should I set my PATH?</para></question> -<answer> - -<para>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 -<literal>setup.exe</literal>. The line is -</para> -<screen> - PATH="/usr/local/bin:/usr/bin:/bin:$PATH" -</screen> - -<para>Effectively, this <emphasis role='bold'>prepends</emphasis> /usr/local/bin and /usr/bin to your -Windows system path. If you choose to reset your PATH, say in -$HOME/.bashrc, or by editing etc/profile directly, then you should -follow this rule. You <emphasis role='bold'>must</emphasis> have <literal>/usr/bin</literal> in your PATH -<emphasis role='bold'>before</emphasis> 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. -</para> -<para>If you're using another shell than bash (say, tcsh), the mechanism -is the same, just the names of the login scripts are different. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.not-found"> -<question><para>Bash (or another shell) says "command not found", but it's right there!</para></question> -<answer> - -<para>If you compile a program, you might find that you can't run it: -</para> -<screen> - bash$ gcc -o hello hello.c - bash$ hello - bash: hello: command not found -</screen> - -<para>Unlike the Windows default behaviour, Unix shells like bash do not look for programs in <literal>.</literal> (the current -directory) by default. You can add <literal>.</literal> 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: -</para> -<screen> - bash$ gcc -o hello hello.c - bash$ ./hello - Hello World! -</screen> - -</answer></qandaentry> - -<qandaentry id="faq.using.converting-paths"> -<question><para>How do I convert between Windows and UNIX paths?</para></question> -<answer> - -<para>Use the 'cygpath' utility. Type '<literal>cygpath --help</literal>' for -information. For example (on my installation): -<screen> - bash$ cygpath --windows ~/.bashrc - D:\starksb\.bashrc - bash$ cygpath --unix C:/cygwin/bin/ls.exe - /usr/bin/ls.exe - bash$ cygpath --unix C:\\cygwin\\bin\\ls.exe - /usr/bin/ls.exe -</screen> -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. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.bashrc"> -<question><para>Why doesn't bash read my .bashrc file on startup?</para></question> -<answer> - -<para>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. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.bash-insensitive"> -<question><para>How can I get bash filename completion to be case insensitive?</para></question> -<answer> - -<para>Add the following to your <literal>~/.bashrc</literal> file: -</para> -<screen> - shopt -s nocaseglob -</screen> - -<para>and add the following to your <literal>~/.inputrc</literal> file: -</para> -<screen> - set completion-ignore-case on -</screen> - -</answer></qandaentry> - -<qandaentry id="faq.using.filename-spaces"> -<question><para>Can I use paths/filenames containing spaces in them?</para></question> -<answer> - -<para>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. -</para> -<para>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: -<screen> - bash-2.03$ cd '/cygdrive/c/Program Files' -</screen> -or -<screen> - bash-2.03$ cd /cygdrive/c/Program\ Files -</screen> -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.shortcuts"> -<question><para>Why can't I cd into a shortcut to a directory?</para></question> -<answer> - -<para>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. -</para> -<para>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. -</para> -<para>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. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.find"> -<question><para>I'm having basic problems with find. Why?</para></question> -<answer> - -<para>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. -</para> -<para>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 <literal>-follow</literal> option. This behavior is different than most -other UNIX implementations, but is not likely to change. -</para> -<para>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 <literal>.</literal> and <literal>..</literal> -directories on some filesystems, such as DVD-R UDF, can confuse find. -See the documentation for the option <literal>-noleaf</literal> in the man page. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.su"> -<question><para>Why doesn't <literal>su</literal> work?</para></question> -<answer> - -<para>The <literal>su</literal> 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. -</para> -<para>You should rather install <literal>sshd</literal> and use -<literal>ssh username@localhost</literal> as a <literal>su</literal> -replacement. -</para> -<para>For some technical background into why <literal>su</literal> doesn't work, read -<ulink url="http://www.cygwin.com/ml/cygwin/2003-06/msg00897.html">http://www.cygwin.com/ml/cygwin/2003-06/msg00897.html</ulink> and -related messages. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.man"> -<question><para>Why doesn't <literal>man -k</literal>, -<literal>apropos</literal> or <literal>whatis</literal> work?</para></question> -<answer> - -<para>Before you can use <literal>man -k</literal>, <literal>apropos</literal> -or <literal>whatis</literal>, you -must create the whatis database. Just run the command -</para> -<screen> - /usr/sbin/makewhatis -</screen> - -<para>(it may take a minute to complete). -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.chmod"> -<question><para>Why doesn't <literal>chmod</literal> work?</para></question> -<answer> - -<para>The most common case is that your <literal>/etc/passwd</literal> -or <literal>/etc/group</literal> files are not properly set up. If -<literal>ls -l</literal> shows a group of <literal>mkpasswd</literal> -or <literal>mkgroup</literal>, you need to run one or both of those -commands. -</para> -<para>If you're using FAT32 instead of NTFS, <literal>chmod</literal> -will fail since FAT32 does not provide any permission information. -You should really consider converting the drive to NTFS with -<literal>CONVERT.EXE</literal>. FAT and FAT32 are barely good enough -for memory cards or USB sticks to exchange pictures... -</para> -<para>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 <ulink url="http://cygwin.com/cygwin-ug-net/ntsec.html" /> -for more information on how Cygwin maps Windows permissions. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.shell-scripts"> -<question><para>Why doesn't my shell script work?</para></question> -<answer> - -<para>There are two basic problems you might run into. One is the fact that -<command>/bin/sh</command> is really <command>bash</command>. -It could be missing some features you might expect in -<command>/bin/sh</command>, if you are used to <command>/bin/sh</command> -actually being <command>zsh</command> (MacOS X "Panther") or -<command>ksh</command> (Tru64). -</para> - -<para>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 <literal>chmod +x</literal>. However, -<literal>chmod</literal> 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 -</para> -<screen> - #! /bin/sh -</screen> - -<para>(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 -</para> -<screen> - : - # This is the 2nd line, assume processing by /bin/sh -</screen> - -<para>also works. -</para> -<para>Note that you can use the filesystem flag <literal>cygexec</literal> in -<filename>/etc/fstab</filename> 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. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.printing"> -<question><para>How do I print under Cygwin?</para></question> -<answer> - -<para>lpr is available in the cygutils package. Some <ulink url="http://cygwin.com/ml/cygwin/2008-05/msg00123.html">usage hints</ulink> are available courtesy of Rodrigo Medina. -</para> -<para>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 -<ulink url="http://cygwin.com/ml/cygwin/2001-04/msg00657.html">http://cygwin.com/ml/cygwin/2001-04/msg00657.html</ulink>. Note that the -<literal>file</literal> command is now available as part of Cygwin setup. -</para> -<para>Alternatively, you can use the Windows <literal>print</literal> -command. (It does not seem to be available on Win9x.) Type -</para> -<screen> - bash$ print /\? -</screen> - -<para>for usage instructions (note the <literal>?</literal> must be escaped from the -shell). -</para> -<para>Finally, you can simply <literal>cat</literal> the file to the printer's share name: -</para> -<screen> - bash$ cat myfile > //host/printer -</screen> - -<para>You may need to press the formfeed button on your printer or append the -formfeed character to your file. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.unicode"> -<question><para>Why don't international (Unicode) characters work?</para></question> -<answer> - -<para>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 <ulink url="http://cygwin.com/cygwin-ug-net/setup-locale.html">Internationalization</ulink> -</para> - -<para> Cygwin uses UTF-8 by default. To use a different character set, you -need to set the LC_ALL, LC_CTYPE or LANG environment variables.</para> -</answer></qandaentry> - -<qandaentry id="faq.using.weirdchars"> -<question><para>My application prints international characters but I only -see gray boxes</para></question> -<answer> -<para>In the case of Cygwin programs, this likely means that the -character set as determined by the LC_ALL, LC_CTYPE or LANG environment -variables does not match the one set on the Text page of the Cygwin Terminal's -options. Setting the locale in the terminal's options will set the LANG -variable accordingly.</para> -<para>Non-Cygwin programs in the Cygwin Terminal do not usually take -heed of the locale environment variables. Instead, they often use the -so-called console codepage, which can be determined with the command -<command>cmd /c chcp</command> followed by the appropriate Windows -codepage number. The codepage number for Cygwin's default UTF-8 character -set is 65001.</para> -</answer></qandaentry> - -<qandaentry id="faq.using.multiple-copies"> -<question><para>Is it OK to have multiple copies of the DLL?</para></question> -<answer> -<para>Yes, as long as they are used in strictly separated installations.</para> -<para>The Cygwin DLL has to handle various sharing situations between -multiple processes. It has to keep a process table. It has to maintain -a mount table which is based on the installation path of the Cygwin DLL.</para> -<para>For that reason, the Cygwin DLL maintains shared resources based on -a hash value created from its own installation path. Each Cygwin DLL -on the machine constitutes a Cygwin installation, with the directory -the Cygwin DLL resides in treated as "/bin", the parent directory as "/". -</para> -<para>Therefore, you can install two or more separate Cygwin distros on -a single machine. Each of these installations use their own Cygwin DLL, -and they don't share the default POSIX paths, nor process tables, nor -any other shared resource used to maintain the installation.</para> -<para>However, a clean separation requires that you don't try to run -executables of one Cygwin installation from processes running in another -Cygwin installation. This may or may not work, but the chances that the -result is not what you expect are pretty high.</para> -<para>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. Apart from -mixing executables of different Cygwin installations, this could also happen -if you have one a single Cygwin installation, for example, if you update the -Cygwin package without exiting <emphasis>all</emphasis> Cygwin apps (including -services like sshd) beforehand.</para> -<para>The only DLL that is sanctioned by the Cygwin project is the one that -you get by running <ulink url="http://cygwin.com/install.html">setup.exe</ulink>, -installed in a 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 -<filename>setup.exe</filename>. -</para> -<para>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). -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.third-party.multiple-copies"> -<question><para> -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? -</para></question> -<answer><para> -Usually, if you keep your installation separate, nothing bad should happen. -However, for the user's convenience, and to avoid potential problems which -still can occur, consider to integrate your product with an already existing -Cygwin installation on the user's machine, or, if there is none, consider -to install the official Cygwin distro on behalf of the user and integrate -your tools from there. (If you write a tool to make this easy, consider -contributing it for others to use) -</para></answer></qandaentry> - -<qandaentry id="faq.using.bundling-cygwin"> -<question><para> -Can I bundle Cygwin with my product for free? -</para></question> -<answer><para> -Only if you comply with Cygwin's <ulink -url="http://cygwin.com/licensing.html">license</ulink> 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. -</para></answer></qandaentry> - -<qandaentry id="faq.using.older-cygwin-conflict"> -<question><para> -But doesn't that mean that if some application installs an older Cygwin -DLL on top of a newer DLL, my application will break? -</para></question> -<answer><para> -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 -<xref linkend="faq.using.third-party.multiple-copies"></xref> apply. -If the application installs an older version of the DLL in /bin then you -should complain loudly to the application provider. -</para><para> -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. -</para></answer></qandaentry> - -<qandaentry id="faq.using.missing-packages"> -<question><para>Why isn't package XYZ available in Cygwin?</para></question> -<answer> - -<para>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 -<ulink url="http://cygwin.com/setup.html">http://cygwin.com/setup.html</ulink>. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.old-packages"> -<question><para>Why is the Cygwin package of XYZ so out of date?</para></question> -<answer> - -<para>(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?) -</para> -<para>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. -</para> -<para>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. -</para> -<para>Remember that the operative term here is "volunteer". -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.accessing-drives"> -<question><para>How can I access other drives?</para></question> -<answer> - -<para>You have some flexibility here. -</para> -<para>Cygwin has a builtin "cygdrive prefix" for drives that are not mounted. -You can access any drive, say Z:, as '/cygdrive/z/'. -</para> -<para>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: -<screen> - bash$ cd C:/Windows - bash$ pwd - /cygdrive/c/Windows -</screen> -and -<screen> - bash$ cd C:/cygwin - bash$ pwd - / -</screen> -for a default setup. You could also use backward-slashes in the -Windows path, but these would have to be escaped from the shell. -</para> -<para><emphasis role='bold'>Warning:</emphasis> 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. -</para> -<para>You can avoid the ambiguity of Windows paths, and avoid typing -"/cygdrive", by explicitly mounting drives to posix paths. For example: -<screen> - bash$ mkdir /c - bash$ mount c:/ /c - bash$ ls /c -</screen> -Then <literal>/cygdrive/c/Windows</literal> becomes <literal>/c/Windows</literal> which is a -little less typing. -</para> -<para>Note that you have to enter the mount point into the -<filename>/etc/fstab</filename> file to keep it indefinitely. -The mount command will only add the mount point for the lifetime -of your current Cygwin session. -</para> -<para>You can change the default <literal>cygdrive</literal> prefix and whether it is binmode or textmode using the <filename>/etc/fstab</filename> file -as well. See the Cygwin User's Guide at -<ulink url="http://cygwin.com/cygwin-ug-net/using.html#mount-table">http://cygwin.com/cygwin-ug-net/using.html#mount-table</ulink> -for more details. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.copy-and-paste"> -<question><para>How can I copy and paste into Cygwin console windows?</para></question> -<answer> - -<para>First, consider using mintty instead of the standard console -window. In mintty, selecting with the left-mouse also copies, -and middle-mouse pastes. It couldn't be easier! -</para> -<para>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. -</para> -<para>You can also bind the insert key to paste from the clipboard by adding -the following line to your .inputrc file: -<screen> - "\e[2~": paste-from-clipboard -</screen> -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.firewall"> -<question><para>What firewall should I use with Cygwin? </para></question> -<answer> - -<para>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). -</para> -<para>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. -</para> -<para>See also <ulink url="http://cygwin.com/faq/faq.html#faq.using.bloda" /> -for a list of applications that have been known, at one time or another, to -interfere with the normal functioning of Cygwin. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.sharing-files"> -<question><para>How can I share files between Unix and Windows?</para></question> -<answer> - -<para>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 <literal>scp</literal>, <literal>ftp</literal>, -<literal>rsync</literal>, ... -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.case-sensitive"> -<question><para>Is Cygwin case-sensitive??</para></question> -<answer> - -<para>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 -<literal>Makefile</literal> and <literal>makefile</literal>. Windows can't -tell the difference between files with just different case, so the -configuration fails. -</para> -<para>To help with this problem, Cygwin supports case sensitivity -starting with Cygwin 1.7.0. For a detailed description how to use that -feature see the Cygwin User's Guilde at -<ulink url="http://cygwin.com/cygwin-ug-net/using-specialnames.html">http://cygwin.com/cygwin-ug-net/using-specialnames.html</ulink>. -</para> - -</answer></qandaentry> - -<qandaentry id="faq.using.dos-filenames"> -<question><para>What about DOS special filenames?</para></question> -<answer> - -<para>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 -<literal>aux.sh</literal>. The perl configuration tries to make sure that -<literal>aux.sh</literal> is there, but an operation on a file with the magic -letters 'aux' in it will hang. -</para> -<para>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 -<ulink url="http://cygwin.com/cygwin-ug-net/using-specialnames.html">http://cygwin.com/cygwin-ug-net/using-specialnames.html</ulink> -for a detailed description of what's possible with filenames and what is not. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.hangs"> -<question><para>When it hangs, how do I get it back?</para></question> -<answer> - -<para>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. -</para> -<para>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. -</para> -<para>And, if all else fails, there's always the reset button/power switch. -In theory this should never be necessary, though. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.directory-structure"> -<question><para>Why the weird directory structure?</para></question> -<answer> - -<para>Why do /lib and /usr/lib (and /bin, /usr/bin) point to the same thing? -</para> -<para>Why use mounts instead of symbolic links? -</para> -<para>Can I use a disk root (e.g., C:\) as Cygwin root? Why is this discouraged? -</para> -<para>After a new installation in the default location, your mount points will -look something like this: -</para> -<screen> - bash$ mount - C:\cygwin\bin on /usr/bin type ntfs (binary,auto) - C:\cygwin\lib on /usr/lib type ntfs (binary,auto) - C:\cygwin on / type ntfs (binary,auto) - C: on /cygdrive/c type ntfs (binary,posix=0,user,noumount,auto) -</screen> - -<para>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 <emphasis>really</emphasis> know what you are doing. -</para> -<para>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. -</para> -<para>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. -</para> -<para>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. <emphasis>So don't do this!</emphasis> -</para> -<para>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?) -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.anti-virus"> -<question><para>How do anti-virus programs like Cygwin?</para></question> -<answer> - -<para>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.) -</para> -<para>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. -</para> -<para>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 <literal>C:\cygwin\bin</literal>. Obviously, this could be -exploited by a hostile non-Cygwin program, so do this at your own risk. -</para> -<para>See also <ulink url="http://cygwin.com/faq/faq.html#faq.using.bloda" /> -for a list of applications that have been known, at one time or another, to -interfere with the normal functioning of Cygwin. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.emacs"> -<question><para>Is there a Cygwin port of GNU Emacs?</para></question> -<answer> - -<para>Yes. Install the emacs package. This provides everything you -need in order to run GNU emacs in a terminal window. If you also want -to be able to use the X11 -(<ulink url="http://x.cygwin.com/">http://x.cygwin.com/</ulink>) -GUI, install the emacs-X11 package. In either case, you run emacs by -typing 'emacs' or '/usr/bin/emacs'. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.xemacs"> -<question><para>Is there a Cygwin port of XEmacs?</para></question> -<answer> - -<para>Yes. It can be used in three different modes:</para> -<para><itemizedlist> -<listitem><para>X11 (<ulink url="http://x.cygwin.com/">http://x.cygwin.com/</ulink>) GUI</para></listitem> -</itemizedlist></para> -<para>You have to <emphasis>set</emphasis> the DISPLAY environment variable -before starting xemacs.</para> -<screen> - bash$ DISPLAY=127.0.0.1:0 xemacs & -</screen> -<para><itemizedlist> -<listitem><para>Windows native GUI</para></listitem> -</itemizedlist></para> -<para>You have to <emphasis>unset</emphasis> the DISPLAY environment variable -before starting xemacs.</para> -<screen> - bash$ DISPLAY= xemacs & -</screen> -<para><itemizedlist> -<listitem><para>Console mode</para></listitem> -</itemizedlist></para> -<para>Start xemacs with -nw in a terminal (native or X11) window</para> -<screen> - bash$ xemacs -nw -</screen> -<para>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. -</para> -<para>To use all the standard packages with XEmacs you should download the following -two packages:</para> -<para><itemizedlist> -<listitem><para>xemacs-sumo - XEmacs standard packages</para></listitem> -<listitem><para>xemacs-mule-sumo - XEmacs MULE (MUlti Lingual Emacs) packages</para></listitem> -</itemizedlist></para> -<para>An alternative <emphasis>native</emphasis> distribution of XEmacs for -Windows based systems can be downloaded from -<ulink url="http://xemacs.org/Download/win32/index.html">http://xemacs.org/Download/win32/index.html</ulink>. -It uses an <emphasis>InnoSetup Kit</emphasis> based installer.</para> -</answer></qandaentry> - -<qandaentry id="faq.using.ntemacs"> -<question><para>What about NT Emacs?</para></question> -<answer> - -<para>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 -<ulink url="http://www.gnu.org/software/emacs/windows/Getting-Emacs.html#Getting-Emacs">Where can I get pre-compiled versions?</ulink> in NT Emacs FAQ. - -</para> -<para>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 (<ulink url="http://jdee.sunsite.dk/">http://jdee.sunsite.dk/</ulink>). The following -settings are for Emacs 21.1: -</para> -<screen> - - ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - ;; 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]*[$] ?")))) - -</screen> - -<para>If you want NT Emacs to understand Cygwin paths, get -cygwin-mount.el from <ulink url="http://www.emacswiki.org/elisp/index.html">http://www.emacswiki.org/elisp/index.html</ulink>. -</para> -<para>Note that all of this ``just works'' if you use the Cygwin port of -Emacs or XEmacs from Cygwin Setup. -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.symlinkstoppedworking"> -<question><para>Why don't some of my old symlinks work anymore?</para></question> -<answer> - -<para>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.</para> - -<para>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.</para> -</answer></qandaentry> - -<qandaentry id="faq.using.symlinks-samba"> -<question><para>Why don't symlinks work on Samba-mounted filesystems?</para></question> -<answer> - -<para>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: -</para> -<screen> - map system = yes - create mask = 0775 -</screen> - -<para>Note that the 0775 can be anything as long as the 0010 bit is set. -</para> -<para>Alternatively, use Windows shortcuts as symlinks. See the CYGWIN -environment variable option "winsymlinks" -<ulink url="http://cygwin.com/cygwin-ug-net/using-cygwinenv.html">http://cygwin.com/cygwin-ug-net/using-cygwinenv.html</ulink> -</para> -</answer></qandaentry> - -<qandaentry id="faq.using.sshd-in-domain"> -<question><para>How do I setup sshd in a domain?</para></question> -<answer> - -<para> -If you want to be able to logon with domain accounts to a domain member -machine, you should make sure that the "cyg_server" account under which -the sshd service is usually running, is a domain account. Otherwise you -might end up with weird problems. For instance, sshd might fail to load -the child process when trying to login with a domain account. A potential, -confirmed error message is -</para> - -<screen> - *** fatal error - unable to load user32.dll, Win32 error 1114 -</screen>. - -<para> -Here's how you set up a sshd with a domain service account. -</para> - -<para> -First of all, create a new domain account called "cyg_server". This -account must be an administrative account, so make sure it's in the -"Administrators" group. Now create a domain policy which is propagated -to all machines which are supposed to run an sshd service. This domain -policy should give the following user rights to the "cyg_server" account: -</para> - -<screen> - Act as part of the operating system (SeTcbPrivilege) - Create a token object (SeCreateTokenPrivilege) - Replace a process level token (SeAssignPrimaryTokenPrivilege) -</screen> - -<para> -Now to install sshd on the member machine, logon to that machine as -an admin. Make sure the aforementioend global policy has been propagated -to this machine. Examine the Local Security Policy settings and, if -necessary, call gpupdate. -</para> - -<para> -If everything looks ok, run bash. Starting with Windows Vista, make -sure you're running bash elevated. -</para> - -<para> -If "cyg_server" is not already in <literal>/etc/passwd</literal>, add it -using <literal>mkpasswd</literal>. Make sure all domain accounts which are -supposed to be able to logon via ssh are in <literal>/etc/passwd</literal>. -Also make sure that all important domain groups are in -<literal>/etc/group</literal>. If in doubt, call -</para> - -<screen> - $ mkpasswd -l -d your_domain > /etc/passwd - $ mkgroup -l -d your_domain > /etc/group -</screen> - -<para> -Then run ssh-host-config. Answer all questions so that "cyg_server" is -used to run the service. When done, check ownership of -<literal>/var/empty</literal> and all <literal>/etc/ssh*</literal> -files. All of them must be owned by "cyg_server". If that's ok, you're -usually all set and you can start the sshd service via -</para> - -<screen> - $ cygrunsrv -S sshd -</screen> - -<para>or</para> - -<screen> - $ net start sshd -</screen> - -</answer></qandaentry> - -<qandaentry id="faq.using.tcl-tk"> -<question><para>Why do my Tk programs not work anymore?</para></question> -<answer> - -<para>Previous versions of Tcl/Tk distributed with Cygwin (e.g. tclsh84.exe, -wish84.exe) were not actually "Cygwin versions" of those tools. -They were built as native libraries, which means they did not understand -Cygwin mounts or symbolic links. This lead to all sorts of problems interacting -with true Cygwin programs.</para> - -<para>As of February 2012, this was replaced with a version of Tcl/Tk which -uses Cygwin's POSIX APIs and X11 for GUI functionality. If you get a message -such as this when trying to start a Tk app:</para> - -<screen> - Application initialization failed: couldn't connect to display "" -</screen> - -<para>Then you need to start an X server, or if one is already running, set the -<literal>DISPLAY</literal> variable to the proper value. The Cygwin distribution -includes an X server; please see the <ulink url="http://x.cygwin.com/docs/ug/cygwin-x-ug.html">Cygwin/X User Guide</ulink> -for installation and startup instructions. -</para></answer></qandaentry> - -<qandaentry id="faq.using.ipv6"> -<question><para>Why do I get "Address family not supported" errors when playing with IPv6?</para></question> -<answer> - -<para>IPv6 is only fully supported and available right from the start -beginning with Windows Vista and Windows Server 2008.</para> - -<para>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. Note, however, that the IPv6 stack on these systems -don't fully support all features of IPv6.</para> - -<para>For more information about IPv6 on Windows and how to install the -IPv6 stack, see the <ulink url="http://www.microsoft.com/technet/network/ipv6/ipv6faq.mspx">Microsoft TechNet IPv6 FAQ article</ulink> -</para></answer></qandaentry> - -<qandaentry id="faq.using.bloda" xreflabel="BLODA"> -<question><para>What applications have been found to interfere with Cygwin?</para></question> -<answer> - -<para>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. -</para> -<para>Among the software that has been found to cause difficulties are:</para> -<para><itemizedlist> -<listitem><para>Sonic Solutions burning software containing DLA component (when DLA disabled)</para></listitem> -<listitem><para>Norton/McAfee/Symantec antivirus or antispyware</para></listitem> -<listitem><para>Logitech webcam software with "Logitech process monitor" service</para></listitem> -<listitem><para>Kerio, Agnitum or ZoneAlarm Personal Firewall</para></listitem> -<listitem><para>Iolo System Mechanic/AntiVirus/Firewall</para></listitem> -<listitem><para>LanDesk</para></listitem> -<listitem><para>Windows Defender </para></listitem> -<listitem><para>Various programs by Wave Systems Corp using wxvault.dll, including Embassy Trust Suite and Embassy Security Center</para></listitem> -<listitem><para>NOD32 Antivirus</para></listitem> -<listitem><para>ByteMobile laptop optimization client</para></listitem> -<listitem><para>Earthlink Total-Access</para></listitem> -<listitem><para>Spybot S&D TeaTimer</para></listitem> -<listitem><para>AR Soft RAM Disk</para></listitem> -<listitem><para>ATI Catalyst (some versions)</para></listitem> -<listitem><para>NVIDIA GeForce (some versions)</para></listitem> -<listitem><para>Windows LiveOneCare</para></listitem> -<listitem><para>Webroot Spy Sweeper with Antivirus</para></listitem> -<listitem><para>COMODO Firewall Pro</para></listitem> -<listitem><para>PC Tools Spyware Doctor</para></listitem> -<listitem><para>Avira AntiVir</para></listitem> -<listitem><para>Panda Internet Security</para></listitem> -<listitem><para>BitDefender</para></listitem> -<listitem><para>Google Desktop</para></listitem> -<listitem><para>Sophos Anti-Virus 7</para></listitem> -<listitem><para>Bufferzone from Trustware</para></listitem> -<listitem><para>Lenovo IPS Core Service (ipssvc)</para></listitem> -<listitem><para>Credant Guardian Shield</para></listitem> -<listitem><para>AVAST (disable FILESYSTEM and BEHAVIOR realtime shields)</para></listitem> -<listitem><para>Citrix Metaframe Presentation Server/XenApp (see <ulink url="http://support.citrix.com/article/CTX107825">Citrix Support page</ulink>)</para></listitem> -</itemizedlist></para> -<para>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. -</para> -<para>Some of the symptoms you may experience are:</para> -<para><itemizedlist> -<listitem> -<para>Random fork() failures.</para> -<para>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. -</para> -</listitem> -<listitem> -<para>File access problems.</para> -<para>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. -</para> -</listitem> -<listitem> -<para>Networking issues</para> -<para>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.</para> -</listitem> -<listitem> -<para>Memory and/or handle leaks</para> -<para>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.</para> -</listitem> -</itemizedlist></para> -</answer></qandaentry> - -<qandaentry id='faq.using.fixing-fork-failures'> - <question><para>How do I fix <literal>fork()</literal> failures?</para></question> - <answer> - <para>Unfortunately, Windows does not use the fork/exec model of process creation - found in UNIX-like OSes, so it is difficult for Cygwin to implement a reliable and - correct <literal>fork()</literal>, which can lead to error messages such as:</para> - <para><itemizedlist> - <listitem>unable to remap <emphasis>somedll</emphasis> to same address as parent</listitem> - <listitem>couldn't allocate heap</listitem> - <listitem>died waiting for dll loading</listitem> - <listitem>child -1 - died waiting for longjmp before initialization</listitem> - <listitem>STATUS_ACCESS_VIOLATION</listitem> - <listitem>resource temporarily unavailable</listitem> - </itemizedlist></para> - <para>Potential solutions for the above errors:</para> - <para><itemizedlist> - <listitem>Restart whatever process is trying (and failing) to use - <literal>fork()</literal>. Sometimes Windows sets up a process - environment that is even more hostile to fork() than usual.</listitem> - <listitem>Ensure that you have eliminated (not just disabled) all - software on the <xref linkend="faq.using.bloda"/>. - </listitem> - <listitem>Read the 'rebase' package README in - <literal>/usr/share/doc/rebase/</literal>, and follow the - instructions there to run 'rebaseall'.</listitem> - </itemizedlist></para> - <para>Please note that installing new packages or updating existing - ones undoes the effects of rebaseall and often causes fork() failures - to reappear. If so, just run rebaseall again. - </para> - <para>See the <ulink url="http://cygwin.com/cygwin-ug-net/highlights.html#ov-hi-process"> - process creation</ulink> section of the User's Guide for the technical reasons it is so - difficult to make <literal>fork()</literal> work reliably.</para> -</answer> -</qandaentry> -</qandadiv> |