newlib-cygwin/winsup/utils/utils.sgml

<sect1 id="using-utils"><title>Cygwin Utilities</title>

<para>Cygwin comes with a number of command-line utilities that are
used to manage the UNIX emulation portion of the Cygwin environment.
While many of these reflect their UNIX counterparts, each was written
specifically for Cygwin.  You may use the long or short option names 
interchangeably; for example, <literal>--help</literal> and 
<literal>-h</literal> function identically. All of the Cygwin 
command-line utilities support the <literal>--help</literal> and
<literal>--version</literal> options. 
</para>

<sect2 id="cygcheck"><title>cygcheck</title>

<screen>
Usage: cygcheck [-v] [-h] PROGRAM
       cygcheck -c [-d] [PACKAGE]
       cygcheck -s [-r] [-v] [-h]
       cygcheck -k
       cygcheck -f FILE [FILE]...
       cygcheck -l [PACKAGE]...
       cygcheck -p REGEXP
       cygcheck --delete-orphaned-installation-keys
       cygcheck --enable-unique-object-names Cygwin-DLL
       cygcheck --disable-unique-object-names Cygwin-DLL
       cygcheck --show-unique-object-names Cygwin-DLL
       cygcheck -h
List system information, check installed packages, or query package database.

At least one command option or a PROGRAM is required, as shown above.

  PROGRAM              list library (DLL) dependencies of PROGRAM
  -c, --check-setup    show installed version of PACKAGE and verify integrity
                       (or for all installed packages if none specified)
  -d, --dump-only      just list packages, do not verify (with -c)
  -s, --sysinfo        produce diagnostic system information (implies -c -d)
  -r, --registry       also scan registry for Cygwin settings (with -s)
  -k, --keycheck       perform a keyboard check session (must be run from a
                       plain console only, not from a pty/rxvt/xterm)
  -f, --find-package   find the package to which FILE belongs
  -l, --list-package   list contents of PACKAGE (or all packages if none given)
  -p, --package-query  search for REGEXP in the entire cygwin.com package
                       repository (requires internet connectivity)
  --delete-orphaned-installation-keys
                       Delete installation keys of old, now unused
                       installations from the registry.  Requires the right
                       to change the registry.
  --enable-unique-object-names Cygwin-DLL
  --disable-unique-object-names Cygwin-DLL
  --show-unique-object-names Cygwin-DLL
                       Enable, disable, or show the setting of the
                       \"unique object names\" setting in the Cygwin DLL
                       given as argument to this option.  The DLL path must
                       be given as valid Windows(!) path.
                       See the users guide for more information.
                       If you don't know what this means, don't change it.
  -v, --verbose        produce more verbose output
  -h, --help           annotate output with explanatory comments when given
                       with another command, otherwise print this help
  -V, --version        print the version of cygcheck and exit

Note: -c, -f, and -l only report on packages that are currently installed. To
  search all official Cygwin packages use -p instead.  The -p REGEXP matches
  package names, descriptions, and names of files/paths within all packages.
</screen>

<para>
The <command>cygcheck</command> program is a diagnostic utility for
dealing with Cygwin programs. If you are familiar with
<command>dpkg</command> or <command>rpm</command>,
<command>cygcheck</command> is similar in many ways. (The major difference
is that <command>setup.exe</command> handles installing and uninstalling
packages; see <xref linkend="internet-setup"></xref> for more information.)
</para>
<para>
The <literal>-c</literal> option checks the version and status of 
installed Cygwin packages. If you specify one or more package names,
<command>cygcheck</command> will limit its output to those packages,
or with no arguments it lists all packages. A package will be marked
<literal>Incomplete</literal> if files originally installed are no longer
present. The best thing to do in that situation is reinstall the package
with <command>setup.exe</command>. To see which files are missing, use the
<literal>-v</literal> option. If you do not need to know the status
of each package and want <command>cygcheck</command> to run faster, add the
<literal>-d</literal> option and <command>cygcheck</command> will only
output the name and version for each package.
</para>
<para>
If you list one or more programs on the command line,
<command>cygcheck</command> will diagnose the runtime environment of that
program or programs, providing the names of DLL files on which the program
depends.  If you specify the <literal>-s</literal> option,
<command>cygcheck</command> will give general system information.  If you
list one or more programs on the command line and specify
<literal>-s</literal>, <command>cygcheck</command> will report on
both.</para>
<para>
The <literal>-f</literal> option helps you to track down which package a
file came from, and <literal>-l</literal> lists all files in a package.
For example, to find out about <filename>/usr/bin/less</filename> and its
package:
<example id="utils-cygcheck-ex"><title>Example <command>cygcheck</command> usage</title>
<screen>
$ cygcheck -f /usr/bin/less
less-381-1

$ cygcheck -l less
/usr/bin/less.exe
/usr/bin/lessecho.exe
/usr/bin/lesskey.exe
/usr/man/man1/less.1
/usr/man/man1/lesskey.1
</screen>
</example>
</para>

<para>The <literal>-h</literal> option prints additional helpful
messages in the report, at the beginning of each section.  It also
adds table column headings.  While this is useful information, it also
adds some to the size of the report, so if you want a compact report
or if you know what everything is already, just leave this out.</para>

<para>The <literal>-v</literal> option causes the output to be more
verbose.  What this means is that additional information will be
reported which is usually not interesting, such as the internal
version numbers of DLLs, additional information about recursive DLL
usage, and if a file in one directory in the PATH also occurs in other
directories on the PATH.  </para>

<para>The <literal>-r</literal> option causes
<command>cygcheck</command> to search your registry for information
that is relevent to Cygwin programs.  These registry entries are the
ones that have "Cygwin" in the name.  If you are paranoid about
privacy, you may remove information from this report, but please keep
in mind that doing so makes it harder to diagnose your problems.</para>

<para>In contrast to the other options that search the packages that are
installed on your local system, the <literal>-p</literal> option can be used
to search the entire official Cygwin package repository.  It takes as argument
a Perl-compatible regular expression which is used to match package names, 
package descriptions, and path/filenames of the contents of packages.  This
feature requires an active internet connection, since it must query the
<literal>cygwin.com</literal> web site.  In fact, it is equalivant to the
search that is available on the <ulink url="http://cygwin.com/packages/">Cygwin
package listing</ulink> page.</para>

<para>For example, perhaps you are getting an error because you are missing a
certain DLL and you want to know which package includes that file:
<example id="utils-search-ex"><title>Searching all packages for a file</title>
<screen>
$ cygcheck -p 'cygintl-2\.dll'
Found 1 matches for 'cygintl-2\.dll'.

libintl2-0.12.1-3         GNU Internationalization runtime library

$ cygcheck -p 'libexpat.*\.a'
Found 2 matches for 'libexpat.*\.a'.

expat-1.95.7-1            XML parser library written in C
expat-1.95.8-1            XML parser library written in C

$ cygcheck -p '/ls\.exe'
Found 2 matches for '/ls\.exe'.

coreutils-5.2.1-5         GNU core utilities (includes fileutils, sh-utils and textutils)
coreutils-5.3.0-6         GNU core utilities (includes fileutils, sh-utils and textutils)
</screen>
</example>
</para>

<para>Note that this option takes a regular expression, not a glob or wildcard.
This means that you need to use <literal>.*</literal> if you want something
similar to the wildcard <literal>*</literal> commonly used in filename globbing.
Similarly, to match the period character you should use <literal>\.</literal>
since the <literal>.</literal> character in a regexp is a metacharacter that
will match any character.  Also be aware that the characters such as 
<literal>\</literal> and <literal>*</literal> are shell metacharacters, so 
they must be either escaped or quoted, as in the example above.</para>

<para>The third example above illustrates that if you want to match a whole 
filename, you should include the <literal>/</literal> path seperator.  In the
given example this ensures that filenames that happen to end in
<literal>ls.exe</literal> such as <literal>ncftpls.exe</literal> are not shown.
Note that this use does not mean "look for packages with <literal>ls</literal>
in the root directory," since the <literal>/</literal> can match anywhere in the
path.  It's just there to anchor the match so that it matches a full
filename.</para>

<para>By default the matching is case-sensitive.  To get a case insensitive
match, begin your regexp with <literal>(?i)</literal> which is a PCRE-specific
feature.  For complete documentation on Perl-compatible regular expression
syntax and options, read the <command>perlre</command> manpage, or one of many
websites such as <literal>perldoc.com</literal> that document the Perl
language.</para>

<para>The <command>cygcheck</command> program should be used to send
information about your system for troubleshooting when requested.  
When asked to run this command save the output so that you can email it,
for example:</para>

<screen>
<prompt>$</prompt> <userinput>cygcheck -s -v -r -h &gt; cygcheck_output.txt</userinput>
</screen>

<para>
Each Cygwin DLL stores its path and installation key in the registry.
This allows troubleshooting of problems which could be a result of having
multiple concurrent Cygwin installations.  However, if you're experimenting
a lot with different Cygwin installation paths, your registry could 
accumulate a lot of old Cygwin installation entries for which the
installation doesn't exist anymore.  To get rid of these orphaned registry
entries, use the <command>cygcheck --delete-orphaned-installation-keys</command>
command.</para>

<para>
Each Cygwin DLL generates a key value from its installation path.  This
value is not only stored in the registry, it's also used to generate
global object names used for interprocess communication.   This keeps
different Cygwin installations separate.  Processes running under a
Cygwin DLL installed in C:\cygwin don't see processes running under a
Cygwin DLL installed in C:\Program Files\cygwin.  This allows
running multiple versions of Cygwin DLLs without these versions to
interfere with each other, or to run small third-party installations
for a specific purpose independently from a Cygwin net distribution.
</para>

<para>
For debugging purposes it could be desired that the various Cygwin DLLs
use the same key, independently from their installation paths.  If the
DLLs have different versions, trying to run processes under these DLLs
concurrently will result in error messages like this one:</para>

<screen>
*** shared version mismatch detected - 0x8A88009C/0x75BE0074.
This problem is probably due to using incompatible versions of the cygwin DLL.
Search for cygwin1.dll using the Windows Start->Find/Search facility
and delete all but the most recent version.  The most recent version *should*
reside in x:\\cygwin\\bin, where 'x' is the drive on which you have
installed the cygwin distribution.  Rebooting is also suggested if you
are unable to find another cygwin DLL.
</screen>

<para>
To disable the usage of a unique key value of a certain Cygwin DLL, use
the <command>cygcheck --disable-unique-object-names Cygwin-DLL</command>
command.  <literal>Cygwin-DLL</literal> is the Windows path (*not* a 
Cygwin POSIX path) to the DLL for which you want to disable this feature.
Note that you have to stop all Cygwin processes running under this DLL,
before you're allowed to change this setting.  For instance, run
<command>cygcheck</command> from a DOS command line for this purpose.</para>

<para>To re-enable the usage of a unique key, use the
<command>cygcheck --enable-unique-object-names Cygwin-DLL</command> command.
This option has the same characteristics as the
<literal>--disable-unique-object-names</literal> option</para>

<para>Finally, you can use
<command>cygcheck --show-unique-object-names Cygwin-DLL</command> to find out
if the given Cygwin DLL use unique object names or not.  In contrast to the
<literal>--disable-...</literal> and <literal>--enable-...</literal> options,
the <literal>--show-unique-object-names</literal> option also works for
Cygwin DLLs which are currently in use.</para>

</sect2>

<sect2 id="cygpath"><title>cygpath</title>

<screen>
Usage: cygpath (-d|-m|-u|-w|-t TYPE) [-f FILE] [OPTION]... NAME...
       cygpath [-c HANDLE] 
       cygpath [-ADHOPSW] 
       cygpath [-F ID] 
Convert Unix and Windows format paths, or output system path information

Output type options:
  -d, --dos             print DOS (short) form of NAMEs (C:\PROGRA~1\)
  -m, --mixed           like --windows, but with regular slashes (C:/WINNT)
  -M, --mode            report on mode of file (currently binmode or textmode)
  -u, --unix            (default) print Unix form of NAMEs (/cygdrive/c/winnt)
  -w, --windows         print Windows form of NAMEs (C:\WINNT)
  -t, --type TYPE       print TYPE form: 'dos', 'mixed', 'unix', or 'windows'
Path conversion options:
  -a, --absolute        output absolute path
  -l, --long-name       print Windows long form of NAMEs (with -w, -m only)
  -p, --path            NAME is a PATH list (i.e., '/bin:/usr/bin')
  -s, --short-name      print DOS (short) form of NAMEs (with -w, -m only)
  -C, --codepage CP     print DOS, Windows, or mixed pathname in Windows
                        codepage CP.  CP can be a numeric codepage identifier,
                        or one of the reserved words ANSI, OEM, or UTF8.
                        If this option is missing, cygpath defaults to the
                        character set defined by the current locale.
System information:
  -A, --allusers        use `All Users' instead of current user for -D, -P
  -D, --desktop         output `Desktop' directory and exit
  -H, --homeroot        output `Profiles' directory (home root) and exit
  -O, --mydocs          output `My Documents' directory and exit
  -P, --smprograms      output Start Menu `Programs' directory and exit
  -S, --sysdir          output system directory and exit
  -W, --windir          output `Windows' directory and exit
  -F, --folder ID       output special folder with numeric ID and exit
Other options:
  -f, --file FILE       read FILE for input; use - to read from STDIN
  -o, --option          read options from FILE as well (for use with --file)
  -c, --close HANDLE    close HANDLE (for use in captured process)
  -i, --ignore          ignore missing argument
  -h, --help            output usage information and exit
  -v, --version         output version information and exit
</screen>

<para>The <command>cygpath</command> program is a utility that
converts Windows native filenames to Cygwin POSIX-style pathnames and
vice versa.  It can be used when a Cygwin program needs to pass a file 
name to a native Windows program, or expects to get a file name from a
native Windows program.  Alternatively, <command>cygpath</command> can 
output information about the location of important system directories 
in either format.  
</para>

<para>The <literal>-u</literal> and <literal>-w</literal> options
indicate whether you want a conversion to UNIX (POSIX) format 
(<literal>-u</literal>) or to Windows format (<literal>-w</literal>).  
Use the <literal>-d</literal> to get DOS-style (8.3) file and path names.
The <literal>-m</literal> option will output Windows-style format
but with forward slashes instead of backslashes.  This option is 
especially useful in shell scripts, which use backslashes as an escape 
character.</para>

<para> In combination with the <literal>-w</literal> option, you can use
the <literal>-l</literal> and <literal>-s</literal> options to use normal
(long) or DOS-style (short) form. The <literal>-d</literal> option is 
identical to <literal>-w</literal> and <literal>-s</literal> together.
</para>

<para>The <literal>-C</literal> option allows to specify a Windows codepage
to print DOS and Windows paths created with one of the <literal>-d</literal>,
<literal>-m</literal>, or <literal>-w</literal> options.  The default is to
use the character set of the current locale defined by one of the
internationalization environment variables <envar>LC_ALL</envar>,
<envar>LC_CTYPE</envar>, or <envar>LANG</envar>, see
<xref linkend="setup-locale"></xref>.  This is sometimes not sufficent for
interaction with native Windows tools, which might expect native, non-ASCII
characters in a specific Windows codepage.  Console tools, for instance, might
expect pathnames in the current OEM codepage, while graphical tools like
Windows Explorer might expect pathnames in the current ANSI codepage.</para>

<para>The <literal>-C</literal> option takes a single parameter:</para>
<itemizedlist spacing="compact">
<listitem><para><literal>ANSI</literal>, to specify the current ANSI codepage</para></listitem>
<listitem><para><literal>OEM</literal>, to specify the current OEM (console) codepage</para></listitem>
<listitem><para><literal>UTF8</literal>, to specify UTF-8.</para></listitem>
<listitem><para>A numerical, decimal codepage number, for instance 936 for GBK,
28593 for ISO-8859-3, etc.  A full list of supported codepages is listed on the
Microsoft MSDN page
<ulink url="http://msdn.microsoft.com/en-us/library/dd317756(VS.85).aspx">Code Page Identifiers</ulink>.  A codepage of 0 is the same as if the
<literal>-C</literal> hasn't been specified at all.</para></listitem>
</itemizedlist>

<para>The <literal>-p</literal> option means that you want to convert
a path-style string rather than a single filename.  For example, the
PATH environment variable is semicolon-delimited in Windows, but
colon-delimited in UNIX.  By giving <literal>-p</literal> you are
instructing <command>cygpath</command> to convert between these
formats.</para>

<para>The <literal>-i</literal> option supresses the print out of the
usage message if no filename argument was given.  It can be used in
make file rules converting variables that may be omitted
to a proper format.  Note that <command>cygpath</command> output may 
contain spaces (C:\Program Files) so should be enclosed in quotes.
</para>


<example id="utils-cygpath-ex"><title>Example <command>cygpath</command> usage</title>
<screen>
<![CDATA[
#!/bin/sh
if [ "${1}" = "" ];
	then
		XPATH=".";
	else
		XPATH="$(cygpath -C ANSI -w "${1}")";
fi
explorer $XPATH &
]]>
</screen>
</example>

<para>The capital options 
<literal>-D</literal>, <literal>-H</literal>, <literal>-P</literal>, 
<literal>-S</literal>, and <literal>-W</literal> output directories used 
by Windows that are not the same on all systems, for example 
<literal>-S</literal> might output C:\WINNT\system32 or C:\Windows\System32. 
The <literal>-H</literal> shows the Windows profiles directory that can 
be used as root of home.  The <literal>-A</literal> option forces use of 
the "All Users" directories instead of the current user for the 
<literal>-D</literal>, <literal>-O</literal> and <literal>-P</literal> 
options.
The <literal>-F</literal> outputs other special folders specified by
their internal numeric code (decimal or 0xhex). For valid codes and
symbolic names, see the CSIDL_* definitions in the include file
/usr/include/w32api/shlobj.h from package w32api. The current valid
range of codes for folders is 0 (Desktop) to 59 (CDBurn area).
By default the output is in UNIX (POSIX) format; 
use the <literal>-w</literal> or <literal>-d</literal> options to get
other formats.</para>

</sect2>

<sect2 id="dumper"><title>dumper</title>

<screen>
Usage: dumper [OPTION] FILENAME WIN32PID
Dump core from WIN32PID to FILENAME.core

-d, --verbose  be verbose while dumping
-h, --help     output help information and exit
-q, --quiet    be quiet while dumping (default)
-v, --version  output version information and exit
</screen>

<para>The <command>dumper</command> utility can be used to create a
core dump of running Windows process. This core dump can be later loaded
to <command>gdb</command> and analyzed. One common way to use 
<command>dumper</command> is to plug it into cygwin's Just-In-Time 
debugging facility by adding

<screen>
error_start=x:\path\to\dumper.exe
</screen>

to the <emphasis>CYGWIN</emphasis> environment variable. Please note that
<literal>x:\path\to\dumper.exe</literal> is Windows-style and not cygwin
path. If <literal>error_start</literal> is set this way, then dumper will
be started whenever some program encounters a fatal error.
</para>

<para>
<command>dumper</command> can be also be started from the command line to 
create a core dump of any running process. Unfortunately, because of a Windows 
API limitation, when a core dump is created and <command>dumper</command> 
exits, the target process is terminated too.
</para>

<para>
To save space in the core dump, <command>dumper</command> doesn't write those
portions of target process' memory space that are loaded from executable and
dll files and are unchangeable, such as program code and debug info. Instead,
<command>dumper</command> saves paths to files which contain that data. When a
core dump is loaded into gdb, it uses these paths to load appropriate files.
That means that if you create a core dump on one machine and try to debug it on
another, you'll need to place identical copies of the executable and dlls in 
the same directories as on the machine where the core dump was created.
</para>

</sect2>

<sect2 id="getfacl"><title>getfacl</title>

<screen>
Usage: getfacl [-adn] FILE [FILE2...]
Display file and directory access control lists (ACLs).

  -a, --all      display the filename, the owner, the group, and
                 the ACL of the file
  -d, --dir      display the filename, the owner, the group, and
                 the default ACL of the directory, if it exists
  -h, --help     output usage information and exit
  -n, --noname   display user and group IDs instead of names
  -v, --version  output version information and exit

When multiple files are specified on the command line, a blank
line separates the ACLs for each file.
</screen>

<para>
For each argument that is a regular file, special file or
directory, <command>getfacl</command> displays the owner, the group, and the 
ACL.  For directories <command>getfacl</command> displays additionally the 
default ACL.  With no options specified, <command>getfacl</command> displays 
the filename, the owner, the group, and both the ACL and the default ACL, if 
it exists. For more information on Cygwin and Windows ACLs, see
<xref linkend="ntsec"></xref> in the Cygwin User's Guide.
The format for ACL output is as follows:
<screen>
     # file: filename
     # owner: name or uid
     # group: name or uid
     user::perm
     user:name or uid:perm
     group::perm
     group:name or gid:perm
     mask:perm
     other:perm
     default:user::perm
     default:user:name or uid:perm
     default:group::perm
     default:group:name or gid:perm
     default:mask:perm
     default:other:perm
</screen>
</para>
</sect2>

<sect2 id="kill"><title>kill</title>

<screen>
Usage: kill [-f] [-signal] [-s signal] pid1 [pid2 ...]
       kill -l [signal]
Send signals to processes

 -f, --force     force, using win32 interface if necessary
 -l, --list      print a list of signal names
 -s, --signal    send signal (use kill --list for a list)
 -h, --help      output usage information and exit
 -v, --version   output version information and exit
</screen>

<para>The <command>kill</command> program allows you to send arbitrary
signals to other Cygwin programs.  The usual purpose is to end a
running program from some other window when ^C won't work, but you can
also send program-specified signals such as SIGUSR1 to trigger actions
within the program, like enabling debugging or re-opening log files.
Each program defines the signals they understand.</para>

<para>You may need to specify the full path to use <command>kill</command> 
from within some shells, including <command>bash</command>, the default Cygwin
shell. This is because <command>bash</command> defines a 
<command>kill</command> builtin function; see the <command>bash</command>
man page under <emphasis>BUILTIN COMMANDS</emphasis> for more information.
To make sure you are using the Cygwin version, try

<screen>
$ /bin/kill --version
</screen>

which should give the Cygwin <command>kill</command> version number and
copyright information.
</para>

<para>Unless you specific the <literal>-f</literal> option, the "pid" values 
used by <command>kill</command> are the Cygwin pids, not the Windows pids.  
To get a list of running programs and their Cygwin pids, use the Cygwin
<command>ps</command> program. <command>ps -W</command> will display
<emphasis>all</emphasis> windows pids.</para>

<para>The <command>kill -l</command> option prints the name of the
given signal, or a list of all signal names if no signal is given.</para>

<para>To send a specific signal, use the <literal>-signN</literal>
option, either with a signal number or a signal name (minus the "SIG"
part), as shown in these examples:</para>

<example id="utils-kill-ex"><title>Using the kill command</title>
<screen>
<prompt>$</prompt> <userinput>kill 123</userinput>
<prompt>$</prompt> <userinput>kill -1 123</userinput>
<prompt>$</prompt> <userinput>kill -HUP 123</userinput>
<prompt>$</prompt> <userinput>kill -f 123</userinput>
</screen>
</example>

<para>Here is a list of available signals, their numbers, and some
commentary on them, from the file
<literal>&lt;sys/signal.h&gt;</literal>, which should be considered
the official source of this information.</para>

<screen>
SIGHUP       1    hangup
SIGINT       2    interrupt
SIGQUIT      3    quit
SIGILL       4    illegal instruction (not reset when caught)
SIGTRAP      5    trace trap (not reset when caught)
SIGABRT      6    used by abort
SIGEMT       7    EMT instruction
SIGFPE       8    floating point exception
SIGKILL      9    kill (cannot be caught or ignored)
SIGBUS      10    bus error
SIGSEGV     11    segmentation violation
SIGSYS      12    bad argument to system call
SIGPIPE     13    write on a pipe with no one to read it
SIGALRM     14    alarm clock
SIGTERM     15    software termination signal from kill
SIGURG      16    urgent condition on IO channel
SIGSTOP     17    sendable stop signal not from tty
SIGTSTP     18    stop signal from tty
SIGCONT     19    continue a stopped process
SIGCHLD     20    to parent on child stop or exit
SIGCLD      20    System V name for SIGCHLD
SIGTTIN     21    to readers pgrp upon background tty read
SIGTTOU     22    like TTIN for output if (tp-&gt;t_local&amp;LTOSTOP)
SIGIO       23    input/output possible
SIGPOLL     23    System V name for SIGIO
SIGXCPU     24    exceeded CPU time limit
SIGXFSZ     25    exceeded file size limit
SIGVTALRM   26    virtual time alarm
SIGPROF     27    profiling time alarm
SIGWINCH    28    window changed
SIGLOST     29    resource lost (eg, record-lock lost)
SIGPWR      29    power failure
SIGUSR1     30    user defined signal 1
SIGUSR2     31    user defined signal 2
</screen>

</sect2>

<sect2 id="locale"><title>locale</title>

<screen>
Usage: locale [-amsuUvh]
   or: locale [-ck] NAME
Get locale-specific information.

Options:

  -a, --all-locales    List all available supported locales
  -c, --category-name  List information about given category NAME
  -k, --keyword-name   Print information about given keyword NAME
  -m, --charmaps       List all available character maps
  -s, --system         Print system default locale
  -u, --user           Print user's default locale
  -U, --utf            Attach ".UTF-8" to the result
  -v, --verbose        More verbose output
  -h, --help           This text
</screen>

<para><command>locale</command> without parameters prints information about
the current locale environment settings.</para>

<para>The <literal>-u</literal> option prints the current user's Windows
default locale to stdout.  The <literal>-s</literal> option prints the
systems default locale instead.  With the <literal>-U</literal> option
<command>locale</command> appends a ".UTF-8".  This can be used in scripts
to set the Cygwin locale to the Windows user or system default, for instance:
</para>

<screen>
bash$ export LANG=$(locale -uU)
bash$ echo $LANG
en_US.UTF-8
</screen>

<para>The <literal>-a</literal> option is helpful to learn which locales
are supported by your Windows machine.  It prints all available locales
and the allowed modifiers.  Example:</para>

<screen>
bash$ locale -a
C
C.utf8
POSIX
af_ZA
af_ZA.utf8
am_ET
am_ET.utf8
...
be_BY
be_BY.utf8
be_BY@latin
...
ca_ES
ca_ES.utf8
ca_ES@euro
catalan
...
</screen>

<para>The <literal>-v</literal> option prints more detailed information about
each available locale.  Example:</para>

<screen>
bash$ locale -av
locale: af_ZA           archive: /cygdrive/c/Windows/system32/kernel32.dll
-------------------------------------------------------------------------------
 language | Afrikaans
territory | South Africa
  codeset | ISO-8859-1

locale: af_ZA.utf8      archive: /cygdrive/c/Windows/system32/kernel32.dll
-------------------------------------------------------------------------------
 language | Afrikaans
territory | South Africa
  codeset | UTF-8

...

locale: ca_ES@euro      archive: /cygdrive/c/Windows/system32/kernel32.dll
-------------------------------------------------------------------------------
 language | Catalan
territory | Spain
  codeset | ISO-8859-15

locale: catalan         archive: /usr/share/locale/locale.alias
-------------------------------------------------------------------------------
 language | Catalan
territory | Spain
  codeset | ISO-8859-1

...
</screen>

<para>The <literal>-m</literal> option prints the names of the available
charmaps supported by Cygwin to stdout.</para>

<para>Otherwise, if arguments are given, <command>locale</command> prints
the values assigned to these arguments.  Arguments can be names of locale
categories (for instance: LC_CTYPE, LC_MONETARY), or names of keywords
supported in the locale categories (for instance: thousands_sep, charmap).
The <literal>-c</literal> option prints additionally the name of the category.
The <literal>-k</literal> option prints additionally the name of the keyword.
Example:</para>

<screen>
bash$ locale -ck LC_MESSAGES
LC_MESSAGES
yesexpr="^[yY]"
noexpr="^[nN]"
yesstr="yes"
nostr="no"
messages-codeset="UTF-8"
bash$ locale noexpr
^[nN]
</screen>

</sect2>

<sect2 id="mkgroup"><title>mkgroup</title>

<screen>
Usage: mkgroup [OPTION]...
Print /etc/group file to stdout

Options:
   -l,--local [machine[,offset]]
                           print local groups with gid offset offset
                           (from local machine if no machine specified)
   -L,--Local [machine[,offset]]
                           ditto, but generate groupname with machine prefix
   -d,--domain [domain[,offset]]
                           print domain groups with gid offset offset
                           (from current domain if no domain specified)
   -D,--Domain [domain[,offset]]
                           ditto, but generate groupname with machine prefix
   -c,--current            print current group
   -C,--Current            ditto, but generate groupname with machine or
                           domain prefix
   -S,--separator char     for -L, -D, -C use character char as domain\group
                           separator in groupname instead of the default '\'
   -o,--id-offset offset   change the default offset (10000) added to gids
                           in domain or foreign server accounts.
   -g,--group groupname    only return information for the specified group
                           one of -l, -L, -d, -D must be specified, too
   -b,--no-builtin         don't print BUILTIN groups
   -U,--unix grouplist     additionally print UNIX groups when using -l or -L
                           on a UNIX Samba server
                           grouplist is a comma-separated list of groupnames
                           or gid ranges (root,-25,50-100).
			   (enumerating large ranges can take a long time!)
   -s,--no-sids            (ignored)
   -u,--users              (ignored)
   -h,--help               print this message
   -v,--version            print version information and exit

Default is to print local groups on stand-alone machines, plus domain
groups on domain controllers and domain member machines.
</screen>

<para>The <command>mkgroup</command> program can be used to help
configure Cygwin by creating a <filename>/etc/group</filename>
file.  Its use is essential to include Windows security information.</para>

<para>The command is initially called by <command>setup.exe</command> to
create a default <filename>/etc/group</filename>.  This should be
sufficient in most circumstances.  However, especially when working
in a multi-domain environment, you can use <command>mkgroup</command>
manually to create a more complete <filename>/etc/group</filename> file for
all domains.  Especially when you have the same group name used on
multiple machines or in multiple domains, you can use the <literal>-D</literal>,
<literal>-L</literal> and <literal>-C</literal> options to create unique
domain\group style groupnames.</para>
  
<para>Note that this information is static.  If you change the group
information in your system, you'll need to regenerate the group file
for it to have the new information.</para>

<para>The <literal>-d/-D</literal> and <literal>-l/-L</literal> options
allow you to specify where the information comes from, the
local SAM of a machine or from the domain, or both.
With the <literal>-d/-D</literal> options the program contacts a Domain
Controller, which my be unreachable or have restricted access.
Comma-separated from the machine or domain, you can specify an offset
which is used as base added to the group's RID to compute the gid
(offset + RID = gid).  This allows you to create the same gids every time you
re-run <command>mkgroup</command>.
For very simple needs, an entry for the current user's group can be
created by using the option <literal>-c</literal> or <literal>-C</literal>.
If you want to use one of the <literal>-D</literal>, <literal>-L</literal>
or <literal>-C</literal> options, but you don't like the backslash as
domain/group separator, you can specify another separator using the
<literal>-S</literal> option, for instance:</para>

<example id="utils-mkgroup-ex"><title>Setting up group entry for current user with different domain/group separator</title>
<screen>
<prompt>$</prompt> <userinput>mkgroup -C -S+ &gt; /etc/group</userinput>
<prompt>$</prompt> <userinput>cat /etc/group</userinput>
DOMAIN+my_group:S-1-5-21-2913048732-1697188782-3448811101-1144:11144:
</screen>
</example>

<para>The <literal>-o</literal> option allows for special cases
(such as multiple domains) where the GIDs might match otherwise.
The <literal>-g</literal> option only prints the information for one group.
The <literal>-U</literal> option allows you to enumerate the standard UNIX
groups on a Samba machine.  It's used together with
<literal>-l samba-server</literal> or <literal>-L samba-server</literal>.
The normal UNIX groups are usually not enumerated, but they can show
up as a group in <command>ls -l</command> output.
</para>

</sect2>

<sect2 id="mkpasswd"><title>mkpasswd</title>

<screen>
Usage: mkpasswd [OPTIONS]...
Print /etc/passwd file to stdout

Options:
   -l,--local [machine[,offset]]
                           print local user accounts with uid offset offset
                           (from local machine if no machine specified)
   -L,--Local [machine[,offset]]
                           ditto, but generate username with machine prefix
   -d,--domain [domain[,offset]]
                           print domain accounts with uid offset offset
                           (from current domain if no domain specified)
   -D,--Domain [domain[,offset]]
                           ditto, but generate username with domain prefix
   -c,--current            print current user
   -C,--Current            ditto, but generate username with machine or
                           domain prefix
   -S,--separator char     for -L, -D, -C use character char as domain\user
                           separator in username instead of the default '\'
   -o,--id-offset offset   change the default offset (10000) added to uids
                           in domain or foreign server accounts.
   -u,--username username  only return information for the specified user
                           one of -l, -L, -d, -D must be specified, too
   -p,--path-to-home path  use specified path instead of user account home dir
                           or /home prefix
   -m,--no-mount           don't use mount points for home dir
   -U,--unix userlist      additionally print UNIX users when using -l or -L\
                           on a UNIX Samba server
                           userlist is a comma-separated list of usernames
                           or uid ranges (root,-25,50-100).
                           (enumerating large ranges can take a long time!)
   -s,--no-sids            (ignored)
   -g,--local-groups       (ignored)
   -h,--help               displays this message
   -v,--version            version information and exit

Default is to print local accounts on stand-alone machines, domain accounts
on domain controllers and domain member machines.
</screen>

<para>The <command>mkpasswd</command> program can be used to help
configure Cygwin by creating a <filename>/etc/passwd</filename> from
your system information.
Its use is essential to include Windows security information.  However,
the actual passwords are determined by Windows, not by the content of
<filename>/etc/passwd</filename>.</para>

<para>The command is initially called by <command>setup.exe</command> to
create a default <filename>/etc/passwd</filename>.  This should be
sufficient in most circumstances.  However, especially when working
in a multi-domain environment, you can use <command>mkpasswd</command>
manually to create a more complete <filename>/etc/passwd</filename> file for
all domains.  Especially when you have the same user name used on
multiple machines or in multiple domains, you can use the <literal>-D</literal>,
<literal>-L</literal> and <literal>-C</literal> options to create unique
domain\user style usernames.</para>
  
<para>Note that this information is static.  If you change the user
information in your system, you'll need to regenerate the passwd file
for it to have the new information.</para>

<para>The <literal>-d/-D</literal> and <literal>-l/-L</literal> options
allow you to specify where the information comes from, the
local machine or the domain (default or given), or both.
With the  <literal>-d/-D</literal> options the program contacts the Domain
Controller, which may be unreachable or have restricted access.
Comma-separated from the machine or domain, you can specify an offset
which is used as base added to the user's RID to compute the uid
(offset + RID = uid).  This allows to create the same uids every time you
re-run <command>mkpasswd</command>.
An entry for the current user can be created by using the
option <literal>-c</literal> or  <literal>-C</literal>.
If you want to use one of the <literal>-D</literal>, <literal>-L</literal>
or <literal>-C</literal> options, but you don't like the backslash as
domain/group separator, you can specify another separator using the
<literal>-S</literal> option, similar to the <command>mkgroup</command>.
The <literal>-o</literal> option allows for special cases
(such as multiple domains) where the UIDs might match otherwise.
The <literal>-m</literal> option bypasses the current
mount table so that, for example, two users who have a Windows home 
directory of H: could mount them differently.  For more information on
SIDs, see <xref linkend="ntsec"></xref> in the Cygwin User's Guide.  The
<literal>-p</literal> option causes <command>mkpasswd</command> to
use the specified prefix instead of the account home dir or <literal>/home/
</literal>. For example, this command:

<example id="utils-althome-ex"><title>Using an alternate home root</title>
<screen>
<prompt>$</prompt> <userinput>mkpasswd -l -p "$(cygpath -H)" &gt; /etc/passwd</userinput>
</screen>
</example>

would put local users' home directories in the Windows 'Profiles' directory. 
The <literal>-u</literal> option creates just an entry for
the specified user.
The <literal>-U</literal> option allows you to enumerate the standard UNIX
users on a Samba machine.  It's used together with
<literal>-l samba-server</literal> or <literal>-L samba-server</literal>.
The normal UNIX users are usually not enumerated, but they can show
up as file owners in <command>ls -l</command> output.
</para>

</sect2>

<sect2 id="mount"><title>mount</title>

<screen>
Usage: mount [OPTION] [&lt;win32path&gt; &lt;posixpath&gt;]
       mount -a
       mount &lt;posixpath&gt;
Display information about mounted filesystems, or mount a filesystem

  -a, --all                     mount all filesystems mentioned in fstab
  -c, --change-cygdrive-prefix  change the cygdrive path prefix to &lt;posixpath&gt;
  -f, --force                   force mount, don't warn about missing mount
                                point directories
  -h, --help                    output usage information and exit
  -m, --mount-entries           write fstab entries to replicate mount points
                                and cygdrive prefixes
  -o, --options X[,X...]        specify mount options
  -p, --show-cygdrive-prefix    show user and/or system cygdrive path prefix
  -v, --version                 output version information and exit
</screen>

<para>The <command>mount</command> program is used to map your drives
and shares onto Cygwin's simulated POSIX directory tree, much like as is
done by mount commands on typical UNIX systems.  However, in contrast to
mount points given in <filename>/etc/fstab</filename>, mount points
created or changed with <command>mount</command> are not persistent.  They
disappear immediately after the last process of the current user exited.
Please see <xref linkend="mount-table"></xref> for more information on the
concepts behind the Cygwin POSIX file system and strategies for using
mounts. To remove mounts temporarily, use <command>umount</command></para>

<sect3 id="utils-mount"><title>Using mount</title>

<para>If you just type <command>mount</command> with no parameters, it
will display the current mount table for you.</para>

<example id="utils-mount-ex">
<title>Displaying the current set of mount points</title>
<screen>
<prompt>$</prompt> <userinput>mount</userinput>
C:/cygwin/bin on /usr/bin type ntfs (binary)
C:/cygwin/lib on /usr/lib type ntfs (binary)
C:/cygwin on / type ntfs (binary)
C: on /mnt/c type ntfs (binary,user,noumount)
D: on /mnt/d type fat (binary,user,noumount)
</screen>
</example>

<para>In this example, c:/cygwin is the POSIX root and the D drive is
mapped to <filename>/mnt/d</filename>.  Note that in this case, the root
mount is a system-wide mount point that is visible to all users running
Cygwin programs, whereas the <filename>/mnt/d</filename> mount is only
visible to the current user.</para>

<para>The <command>mount</command> utility is also the mechanism for
adding new mounts to the mount table in memory.  The following example
demonstrates how to mount the directory
<filename>//pollux/home/joe/data</filename> to <filename>/data</filename>
for the duration of the current session.
</para>

<example id="utils-mount-add-ex">
<title>Adding mount points</title>
<screen>
<prompt>$</prompt> <userinput>ls /data</userinput>
ls: /data: No such file or directory
<prompt>$</prompt> <userinput>mount //pollux/home/joe/data /data</userinput>
mount: warning - /data does not exist!
<prompt>$</prompt> <userinput>mount</userinput>
//pollux/home/joe/data on /data type smbfs (binary)
C:/cygwin/bin on /usr/bin type ntfs (binary)
C:/cygwin/lib on /usr/lib type ntfs (binary)
C:/cygwin on / type ntfs (binary)
C: on /c type ntfs (binary,user,noumount)
D: on /d type fat (binary,user,noumount)
</screen>
</example>

<para>A given POSIX path may only exist once in the mount table.  Attempts to
replace the mount will fail with a busy error.  The <literal>-f</literal>
(force) option causes the old mount to be silently replaced with the new one,
provided the old mount point was a user mount point.  It's not valid to
replace system-wide mount points.  Additionally, the <literal>-f</literal>
option will silence warnings about the non-existence of directories at the
Win32 path location.</para>

<para>
The <literal>-o</literal> option is the method via which various options about
the mount point may be recorded.  The following options are available (note that
most of the options are duplicates of other mount flags):</para>

<screen>
  acl        - Use the filesystem's access control lists (ACLs) to
               implement real POSIX permissions (default).
  binary     - Files default to binary mode (default).
  bind       - Allows to remount part of the file hierarchy somewhere else.
               Different from other mount calls, the first argument 
	       specifies an absolute POSIX path, rather than a Win32 path.
	       This POSIX path is remounted to the POSIX path specified as
	       the second parameter.  The conversion to a Win32 path is done
	       within Cygwin immediately at the time of the call.  Note that
	       symlinks are ignored while performing this path conversion.
  cygexec    - Treat all files below mount point as cygwin executables.
  dos        - Always convert leading spaces and trailing dots and spaces to
	       characters in the UNICODE private use area.  This allows to use
	       broken filesystems which only allow DOS filenames, even if they
	       are not recognized as such by Cygwin.
  exec       - Treat all files below mount point as executable.
  ihash      - Always fake inode numbers rather than using the ones returned
	       by the filesystem.  This allows to use broken filesystems which
	       don't return unambiguous inode numbers, even if they are not
	       recognized as such by Cygwin.
  noacl      - Ignore ACLs and fake POSIX permissions.
  nosuid     - No suid files are allowed (currently unimplemented)
  notexec    - Treat all files below mount point as not executable.
  override   - Override immutable mount points.
  posix=0    - Switch off case sensitivity for paths under this mount point.
  posix=1    - Switch on case sensitivity for paths under this mount point
               (default).
  text       - Files default to CRLF text mode line endings.
</screen>

<para>For a more complete description of the mount options and the
<filename>/etc/fstab</filename> file, see
<xref linkend="mount-table"></xref>.</para>

<para>Note that all mount points added with <command>mount</command> are
user mount points.  System mount points can only be specified in
the <filename>/etc/fstab</filename> file.</para>

<para>If you added mount points to <filename>/etc/fstab</filename> or your
<filename>/etc/fstab.d/&lt;username&gt;</filename> file, you can add these
mount points to your current user session using the <literal>-a/--all</literal>
option, or by specifing the posix path alone on the command line.  As an
example, consider you added a mount point with the POSIX path
<filename>/my/mount</filename>.  You can add this mount point with either
one of the following two commands to your current user session.</para>

<screen>
<prompt>$</prompt> <userinput>mount /my/mount</userinput>
<prompt>$</prompt> <userinput>mount -a</userinput>
</screen>

<para>The first command just adds the <filename>/my/mount</filename> mount
point to your current session, the <command>mount -a</command> adds all
new mount points to your user session.</para>

<para>If you change a mount point to point to another native path, or
if you changed the flags of a mount point, you have to <command>umount</command>
the mount point first, before you can add it again.  Please note that
all such added mount points are added as user mount points, and that the
rule that system mount points can't be removed or replaced in a running
session still applies.</para>

<para>To bind a POSIX path to another POSIX path, use the
<literal>bind</literal> mount flag.</para>

<screen>
<prompt>$</prompt> <userinput>mount -o bind /var /usr/var</userinput>
</screen>

<para>This command makes the file hirarchy under <filename>/var</filename>
additionally available under <filename>/usr/var</filename>.</para>

<para>
The <literal>-m</literal> option causes the <command>mount</command> utility
to output the current mount table in a series of fstab entries.
You can save this output as a backup when experimenting with the mount table.
Copy the output to <filename>/etc/fstab</filename> to restore the old state.
It also makes moving your settings to a different machine much easier.</para>

</sect3>

<sect3 id="utils-cygdrive"><title>Cygdrive mount points</title>

<para>Whenever Cygwin cannot use any of the existing mounts to convert
from a particular Win32 path to a POSIX one, Cygwin will, instead,
convert to a POSIX path using a default mount point:
<filename>/cygdrive</filename>.  For example, if Cygwin accesses
<filename>z:\foo</filename> and the z drive is not currently in the
mount table, then <filename>z:\</filename> will be accessible as
<filename>/cygdrive/z</filename>.  The <command>mount</command> utility 
can be used to change this default automount prefix through the use of the
"--change-cygdrive-prefix" option.  In the following example, we will
set the automount prefix to <filename>/mnt</filename>:</para>

<example id="utils-cygdrive-ex">
<title>Changing the default prefix</title>
<screen>
<prompt>$</prompt> <userinput>mount --change-cygdrive-prefix /mnt</userinput>
</screen>
</example>

<para>Note that the cygdrive prefix can be set both per-user and system-wide, 
and that as with all mounts, a user-specific mount takes precedence over the 
system-wide setting.  The <command>mount</command> utility creates system-wide 
mounts by default if you do not specify a type.
You can always see the user and system cygdrive prefixes with the 
<literal>-p</literal> option.  Using the <literal>--options</literal>
flag with <literal>--change-cygdrive-prefix</literal> makes all new 
automounted filesystems default to this set of options.  For instance
(using the short form of the command line flags)</para>

<example id="utils-cygdrive-ex2">
<title>Changing the default prefix with specific mount options</title>
<screen>
<prompt>$</prompt> <userinput>mount -c /mnt -o binary,noacl</userinput>
</screen>
</example>


</sect3>

<sect3 id="utils-limitations"><title>Limitations</title>

<para>Limitations: there is a hard-coded limit of 30 mount
points.  Also, although you can mount to pathnames that do not start
with "/", there is no way to make use of such mount points.</para>

<para>Normally the POSIX mount point in Cygwin is an existing empty
directory, as in standard UNIX. If this is the case, or if there is a
place-holder for the mount point (such as a file, a symbolic link
pointing anywhere, or a non-empty directory), you will get the expected
behavior. Files present in a mount point directory before the mount
become invisible to Cygwin programs.
</para>

<para>It is sometimes desirable to mount to a non-existent directory,
for example to avoid cluttering the root directory with names
such as
<filename>a</filename>, <filename>b</filename>, <filename>c</filename>
pointing to disks.
Although <command>mount</command> will give you a warning, most
everything will work properly when you refer to the mount point
explicitly.  Some strange effects can occur however.
For example if your current working directory is
<filename>/dir</filename>,
say, and <filename>/dir/mtpt</filename> is a mount point, then
<filename>mtpt</filename> will not show up in an <command>ls</command>
or
<command>echo *</command> command and <command>find .</command> will
not
find <filename>mtpt</filename>.
</para>

</sect3>

</sect2>

<sect2 id="passwd"><title>passwd</title>

<screen>
Usage: passwd [OPTION] [USER]
Change USER's password or password attributes.

User operations:
  -l, --lock               lock USER's account.
  -u, --unlock             unlock USER's account.
  -c, --cannot-change      USER can't change password.
  -C, --can-change         USER can change password.
  -e, --never-expires      USER's password never expires.
  -E, --expires            USER's password expires according to system's
                           password aging rule.
  -p, --pwd-not-required   no password required for USER.
  -P, --pwd-required       password is required for USER.
  -R, --reg-store-pwd      enter password to store it in the registry for
                           later usage by services to be able to switch
                           to this user context with network credentials.

System operations:
  -i, --inactive NUM       set NUM of days before inactive accounts are disabled
                           (inactive accounts are those with expired passwords).
  -n, --minage DAYS        set system minimum password age to DAYS days.
  -x, --maxage DAYS        set system maximum password age to DAYS days.
  -L, --length LEN         set system minimum password length to LEN.

Other options:
  -d, --logonserver SERVER connect to SERVER (e.g. domain controller).
                           Default server is the local system, unless
                           changing the current user, in which case the
                           default is the content of $LOGONSERVER.
  -S, --status             display password status for USER (locked, expired,
                           etc.) plus global system password settings.
  -h, --help               output usage information and exit.
  -v, --version            output version information and exit.

If no option is given, change USER's password.  If no user name is given,
operate on current user.  System operations must not be mixed with user
operations.  Don't specify a USER when triggering a system operation. 

Don't specify a user or any other option together with the -R option.
Non-Admin users can only store their password if cygserver is running.
Note that storing even obfuscated passwords in the registry is not overly
secure.  Use this feature only if the machine is adequately locked down.
Don't use this feature if you don't need network access within a remote
session.  You can delete your stored password by using `passwd -R' and
specifying an empty password.
</screen>

<para> <command>passwd</command> changes passwords for user accounts.
A normal user may only change the password for their own account,
but administrators may change passwords on any account.
<command>passwd</command> also changes account information, such as
password expiry dates and intervals.</para>

<para>For password changes, the user is first prompted for their old
password, if one is present.  This password is then encrypted and
compared against the stored password.  The user has only one chance to
enter the correct password.  The administrators are permitted to
bypass this step so that forgotten passwords may be changed.</para>

<para>The user is then prompted for a replacement password.
<command>passwd</command> will prompt twice for this replacement and 
compare the second entry against the first.  Both entries are required to 
match in order for the password to be changed.</para>

<para>After the password has been entered, password aging information
is checked to see if the user is permitted to change their password
at this time.  If not, <command>passwd</command> refuses to change the
password and exits.</para>

<para>
To get current password status information, use the
<literal>-S</literal> option. Administrators can use
<command>passwd</command> to perform several account maintenance
functions (users may perform some of these functions on their own
accounts).  Accounts may be locked with the <literal>-l</literal> flag
and unlocked with the <literal>-u</literal> flag.  Similarly,
<literal>-c</literal> disables a user's ability to change passwords, and
<literal>-C</literal> allows a user to change passwords.  For password
expiry, the <literal>-e</literal> option disables expiration, while the
<literal>-E</literal> option causes the password to expire according to
the system's normal aging rules.  Use <literal>-p</literal> to disable
the password requirement for a user, or <literal>-P</literal> to require
a password.
</para>

<para>Administrators can also use <command>passwd</command> to change
system-wide password expiry and length requirements with the
<literal>-i</literal>, <literal>-n</literal>, <literal>-x</literal>,
and <literal>-L</literal> options.  The <literal>-i</literal>
option is used to disable an account after the password has been expired
for a number of days.  After a user account has had an expired password
for <emphasis>NUM</emphasis> days, the user may no longer sign on to
the account.  The <literal>-n</literal> option is
used to set the minimum number of days before a password may be changed.
The user will not be permitted to change the password until
<emphasis>MINDAYS</emphasis> days have elapsed.  The
<literal>-x</literal> option is used to set the maximum number of days
a password remains valid.  After <emphasis>MAXDAYS</emphasis> days, the
password is required to be changed.  Allowed values for the above options 
are 0 to 999.  The <literal>-L</literal> option sets the minimum length of 
allowed passwords for users who don't belong to the administrators group
to <emphasis>LEN</emphasis> characters.  Allowed values for the minimum
password length are 0 to 14.  In any of the above cases, a value of 0
means `no restrictions'.</para>

<para>
All operations affecting the current user are by default run against
the logon server of the current user (taken from the environment
variable <envar>LOGONSERVER</envar>.  When password or account information
of other users should be changed, the default server is the local system.
To change a user account on a remote machine, use the <literal>-d</literal>
option to specify the machine to run the command against.  Note that the
current user must be a valid member of the administrators group on the remote
machine to perform such actions.
</para>

<para>Users can use the <command>passwd -R</command> to enter
a password which then gets stored in a special area of the registry on the
local system, which is also used by Windows to store passwords of accounts
running Windows services.  When a privileged Cygwin application calls the
<command>set{e}uid(user_id)</command> system call, Cygwin checks if a
password for that user has been stored in this registry area.  If so, it
uses this password to switch to this user account using that password.
This allows you to logon through, for instance, <command>ssh</command> with
public key authentication and get a full qualified user token with
all credentials for network access.  However, the method has some
drawbacks security-wise.  This is explained in more detail in
<xref linkend="ntsec"></xref>.</para>

<para>Please note that storing passwords in that registry area is a
privileged operation which only administrative accounts are allowed to
do.  If normal, non-admin users should be allowed to enter their
passwords using <command>passwd -R</command>, it's required to run
<command>cygserver</command> as a service under the LocalSystem account
before running <command>passwd -R</command>.  This only affects storing
passwords.  Using passwords in privileged processes does not require
<command>cygserver</command> to run.</para>

<para>Limitations: Users may not be able to change their password on
some systems.</para>

</sect2>

<sect2 id="ps"><title>ps</title>

<screen>
Usage: ps [-aefls] [-u UID]
Report process status

 -a, --all       show processes of all users
 -e, --everyone  show processes of all users
 -f, --full      show process uids, ppids
 -h, --help      output usage information and exit
 -l, --long      show process uids, ppids, pgids, winpids
 -p, --process   show information for specified PID
 -s, --summary   show process summary
 -u, --user      list processes owned by UID
 -v, --version   output version information and exit
 -W, --windows   show windows as well as cygwin processes
With no options, ps outputs the long format by default
</screen>

<para>The <command>ps</command> program gives the status of all the
Cygwin processes running on the system (ps = "process status").  Due
to the limitations of simulating a POSIX environment under Windows,
there is little information to give.  
</para>

<para>
The PID column is the process ID you need to give to the 
<command>kill</command> command. The PPID is the parent process ID,
and PGID is the process group ID.  The WINPID column is the process 
ID displayed by NT's Task Manager program. The TTY column gives which 
pseudo-terminal a process is running on, or a <literal>'?'</literal>
for services. The UID column shows which user owns each process. 
STIME is the time the process was started, and COMMAND gives the name
of the program running. Listings may also have a status flag in
column zero; <literal>S</literal> means stopped or suspended (in other
words, in the background), <literal>I</literal> means waiting for
input or interactive (foreground), and <literal>O</literal> means
waiting to output. 
</para>

<para>
By default, <command>ps</command> will only show processes owned by the
current user. With either the <literal>-a</literal> or <literal>-e</literal>
option, all user's processes (and system processes) are listed. There are
historical UNIX reasons for the synonomous options, which are functionally
identical. The <literal>-f</literal> option outputs a "full" listing with
usernames for UIDs. The <literal>-l</literal> option is the default display
mode, showing a "long" listing with all the above columns. The other display
option is <literal>-s</literal>, which outputs a shorter listing of just
PID, TTY, STIME, and COMMAND. The <literal>-u</literal> option allows you
to show only processes owned by a specific user. The <literal>-p</literal>
option allows you to show information for only the process with the
specified PID. The <literal>-W</literal>
option causes <command>ps</command> show non-Cygwin Windows processes as 
well as Cygwin processes. The WINPID is also the PID, and they can be killed
with the Cygwin <command>kill</command> command's <literal>-f</literal>
option.
</para>

</sect2>

<sect2 id="regtool"><title>regtool</title>

<screen>
Usage: regtool [OPTION] (add|check|get|list|remove|unset|load|unload|save) KEY
View or edit the Win32 registry

Actions:
 add KEY\SUBKEY             add new SUBKEY
 check KEY                  exit 0 if KEY exists, 1 if not
 get KEY\VALUE              prints VALUE to stdout
 list KEY                   list SUBKEYs and VALUEs
 remove KEY                 remove KEY
 set KEY\VALUE [data ...]   set VALUE
 unset KEY\VALUE            removes VALUE from KEY
 load KEY\SUBKEY PATH       load hive from PATH into new SUBKEY
 unload KEY\SUBKEY          unload hive and remove SUBKEY
 save KEY\SUBKEY PATH       save SUBKEY into new hive PATH

Options for 'list' Action:
 -k, --keys           print only KEYs
 -l, --list           print only VALUEs
 -p, --postfix        like ls -p, appends '\' postfix to KEY names

Options for 'get' Action:
 -b, --binary         print REG_BINARY data as hex bytes
 -n, --none           print data as stream of bytes as stored in registry
 -x, --hex            print numerical data as hex numbers

Options for 'set' Action:
 -b, --binary         set type to REG_BINARY (hex args or '-')
 -D, --dword-be       set type to REG_DWORD_BIG_ENDIAN
 -e, --expand-string  set type to REG_EXPAND_SZ
 -i, --integer        set type to REG_DWORD
 -m, --multi-string   set type to REG_MULTI_SZ
 -n, --none           set type to REG_NONE
 -Q, --qword          set type to REG_QWORD
 -s, --string         set type to REG_SZ

Options for 'set' and 'unset' Actions:
 -K&lt;c&gt;, --key-separator[=]&lt;c&gt;  set key separator to &lt;c&gt; instead of '\'

Other Options:
 -h, --help     output usage information and exit
 -q, --quiet    no error output, just nonzero return if KEY/VALUE missing
 -v, --verbose  verbose output, including VALUE contents when applicable
 -w, --wow64    access 64 bit registry view (ignored on 32 bit Windows)
 -W, --wow32    access 32 bit registry view (ignored on 32 bit Windows)
 -V, --version  output version information and exit

KEY is in the format [host]\prefix\KEY\KEY\VALUE, where host is optional
remote host in either \\hostname or hostname: format and prefix is any of:
  root     HKCR  HKEY_CLASSES_ROOT (local only)
  config   HKCC  HKEY_CURRENT_CONFIG (local only)
  user     HKCU  HKEY_CURRENT_USER (local only)
  machine  HKLM  HKEY_LOCAL_MACHINE
  users    HKU   HKEY_USERS

You can use forward slash ('/') as a separator instead of backslash, in
that case backslash is treated as escape character
Example: regtool.exe get '\user\software\Microsoft\Clock\iFormat'
</screen>

<para>The <command>regtool</command> program allows shell scripts
to access and modify the Windows registry.  Note that modifying the
Windows registry is dangerous, and carelessness here can result
in an unusable system.  Be careful.</para>

<para>The <literal>-v</literal> option means "verbose".  For most
commands, this causes additional or lengthier messages to be printed.
Conversely, the <literal>-q</literal> option supresses error messages,
so you can use the exit status of the program to detect if a key
exists or not (for example).</para>

<para>The <literal>-w</literal> option allows you to access the 64 bit view
of the registry.  Several subkeys exist in a 32 bit and a 64 bit version
when running on Windows 64.  Since Cygwin is running in 32 bit mode, it
only has access to the 32 bit view of these registry keys.  When using
the <literal>-w</literal> switch, the 64 bit view is used and
<command>regtool</command> can access the entire registry.
This option is simply ignored when running on 32 bit Windows versions.
</para>

<para>The <literal>-W</literal> option allows you to access the 32 bit view
on the registry.  The purpose of this option is mainly for symmetry.  It
permits creation of OS agnostic scripts which would also work in a hypothetical
64 bit version of Cygwin.</para>

<para>You must provide <command>regtool</command> with an 
<emphasis>action</emphasis> following options (if any). Currently,
the action must be <literal>add</literal>, <literal>set</literal>,
<literal>check</literal>, <literal>get</literal>, <literal>list</literal>,
<literal>remove</literal>, <literal>set</literal>, or <literal>unset</literal>.
</para>

<para>The <literal>add</literal> action adds a new key.  The 
<literal>check</literal> action checks to see if a key exists (the 
exit code of the program is zero if it does, nonzero if it does not).
The <literal>get</literal> action gets the value of a key,
and prints it (and nothing else) to stdout.  Note: if the value
doesn't exist, an error message is printed and the program returns a
non-zero exit code.  If you give <literal>-q</literal>, it doesn't
print the message but does return the non-zero exit code.</para>

<para>
The <literal>list</literal> action lists the subkeys and values
belonging to the given key. With <literal>list</literal>, the 
<literal>-k</literal> option instructs <command>regtool</command>
to print only KEYs, and the <literal>-l</literal> option to print
only VALUEs. The <literal>-p</literal> option postfixes a 
<literal>'/'</literal> to each KEY, but leave VALUEs with no
postfix.  The <literal>remove</literal> action 
removes a key.  Note that you may need to remove everything in the key 
before you may remove it, but don't rely on this stopping you from 
accidentally removing too much.  
</para>

<para>The <literal>get</literal> action prints a value within a key.
With the <literal>-b</literal> option, data is printed as hex bytes.
<literal>-n</literal> allows to print the data as a typeless stream of
bytes.  Integer values (REG_DWORD, REG_QWORD) are usually printed
as decimal values.  The <literal>-x</literal> option allows to print
the numbers as hexadecimal values.</para>

<para>The <literal>set</literal> action sets a value within a key.
<literal>-b</literal> means it's binary data (REG_BINARY).
The binary values are specified as hex bytes in the argument list.
If the argument is <literal>'-'</literal>, binary data is read
from stdin instead.
<literal>-d</literal> or <literal>-i</literal> means the value is a 32 bit
integer value (REG_DWORD).
<literal>-D</literal> means the value is a 32 bit integer value in
Big Endian representation (REG_DWORD_BIG_ENDIAN).
<literal>-Q</literal> means the value is a 64 bit integer value (REG_QWORD).
<literal>-s</literal> means the value is a string (REG_SZ).
<literal>-e</literal> means it's an expanding string (REG_EXPAND_SZ)
that contains embedded environment variables.  
<literal>-m</literal> means it's a multi-string (REG_MULTI_SZ).  
If you don't specify one of these, <command>regtool</command> tries to
guess the type based on the value you give.  If it looks like a
number, it's a DWORD, unless it's value doesn't fit into 32 bit, in which
case it's a QWORD.  If it starts with a percent, it's an expanding
string.  If you give multiple values, it's a multi-string.  Else, it's
a regular string.</para>

<para>The <literal>unset</literal> action removes a value from a key.</para>

<para>The <literal>load</literal> action adds a new subkey and loads
the contents of a registry hive into it.
The parent key must be HKEY_LOCAL_MACHINE or HKEY_USERS.
The <literal>unload</literal> action unloads the file and removes
the subkey.
</para>

<para>The <literal>save</literal> action saves a subkey into a
registry hive.
</para>

<para>
By default, the last "\" or "/" is assumed to be the separator between the
key and the value.  You can use the <literal>-K</literal> option to provide 
an alternate key/value separator character.
</para>

</sect2>

<sect2 id="setfacl"><title>setfacl</title>

<screen>
Usage: setfacl [-r] (-f ACL_FILE | -s acl_entries) FILE...
       setfacl [-r] ([-d acl_entries] [-m acl_entries]) FILE...
Modify file and directory access control lists (ACLs)

  -d, --delete     delete one or more specified ACL entries
  -f, --file       set ACL entries for FILE to ACL entries read
                   from a ACL_FILE
  -m, --modify     modify one or more specified ACL entries
  -r, --replace    replace mask entry with maximum permissions
                   needed for the file group class
  -s, --substitute substitute specified ACL entries for the
                   ACL of FILE
  -h, --help       output usage information and exit
  -v, --version    output version information and exit

At least one of (-d, -f, -m, -s) must be specified
</screen>

<para>
For each file given as parameter, <command>setfacl</command> will 
either replace its complete ACL (<literal>-s</literal>, <literal>-f</literal>), 
or it will add, modify, or delete ACL entries.
For more information on Cygwin and Windows ACLs, see
see <xref linkend="ntsec"></xref> in the Cygwin User's Guide.
</para>

<para>
Acl_entries are one or more comma-separated ACL entries 
from the following list:
<screen>
         u[ser]::perm
         u[ser]:uid:perm
         g[roup]::perm
         g[roup]:gid:perm
         m[ask]::perm
         o[ther]::perm
</screen>
Default entries are like the above with the additional
default identifier. For example: 
<screen>
         d[efault]:u[ser]:uid:perm
</screen>
</para>

<para>
<emphasis>perm</emphasis> is either a 3-char permissions string in the form
"rwx" with the character <literal>'-'</literal> for no permission
or it is the octal representation of the permissions, a
value from 0 (equivalent to "---") to 7 ("rwx").
<emphasis>uid</emphasis> is a user name or a numerical uid.
<emphasis>gid</emphasis> is a group name or a numerical gid.
</para>

<para>
The following options are supported:
</para>

<para>
<literal>-d</literal>
Delete one or more specified entries from the file's ACL.
The owner, group and others entries must not be deleted.
Acl_entries to be deleted should be specified without
permissions, as in the following list:
<screen>
         u[ser]:uid
         g[roup]:gid
         d[efault]:u[ser]:uid
         d[efault]:g[roup]:gid
         d[efault]:m[ask]:
         d[efault]:o[ther]:
</screen>
</para>

<para>
<literal>-f</literal>
Take the Acl_entries from ACL_FILE one per line. Whitespace
characters are ignored, and the character "#" may be used
to start a comment.  The special filename "-" indicates
reading from stdin. Note that you can use this with 
<command>getfacl</command> and <command>setfacl</command> to copy 
ACLs from one file to another:
<screen>
$ getfacl source_file | setfacl -f - target_file
</screen>
</para>

<para>
Required entries are: 
one user entry for the owner of the file,
one group entry for the group of the file, and
one other entry.
</para>

<para>
If additional user and group entries are given:
a mask entry for the file group class of the file, and 
no duplicate user or group entries with the same uid/gid.
</para>

<para>
If it is a directory:
one default user entry for the owner of the file,
one default group entry for the group of the file,
one default mask entry for the file group class, and
one default other entry.
</para>

<para>
<literal>-m</literal>
Add or modify one or more specified ACL entries.  Acl_entries is a 
comma-separated list of entries from the same list as above.
</para>

<para>
<literal>-r</literal>   
Causes the permissions specified in the mask 
entry to be ignored and replaced by the maximum permissions needed for 
the file group class.
</para>

<para>
<literal>-s</literal>   
Like <literal>-f</literal>, but substitute the 
file's ACL with Acl_entries specified in a comma-separated list on the 
command line.
</para>

<para>
While the <literal>-d</literal> and <literal>-m</literal> options may be used 
in the same command, the <literal>-f</literal> and <literal>-s</literal> 
options may be used only exclusively.
</para>

<para>
Directories may contain default ACL entries.  Files created
in a directory that contains default ACL entries will have
permissions according to the combination of the current umask,
the explicit permissions requested and the default ACL entries
</para>

<para>
Limitations: Under Cygwin, the default ACL entries are not taken into
account currently.
</para>

</sect2>

<sect2 id="ssp"><title>ssp</title>

<screen>
Usage: ssp [options] low_pc high_pc command...
Single-step profile COMMAND

 -c, --console-trace  trace every EIP value to the console. *Lots* slower.
 -d, --disable        disable single-stepping by default; use
                      OutputDebugString ("ssp on") to enable stepping
 -e, --enable         enable single-stepping by default; use
                      OutputDebugString ("ssp off") to disable stepping
 -h, --help           output usage information and exit
 -l, --dll            enable dll profiling.  A chart of relative DLL usage
                      is produced after the run.
 -s, --sub-threads    trace sub-threads too.  Dangerous if you have
                      race conditions.
 -t, --trace-eip      trace every EIP value to a file TRACE.SSP.  This
                      gets big *fast*.
 -v, --verbose        output verbose messages about debug events.
 -V, --version        output version information and exit

Example: ssp 0x401000 0x403000 hello.exe
</screen>

<para>
SSP - The Single Step Profiler
</para>

<para>
Original Author:  DJ Delorie 
</para>

<para>
The SSP is a program that uses the Win32 debug API to run a program
one ASM instruction at a time.  It records the location of each
instruction used, how many times that instruction is used, and all
function calls.  The results are saved in a format that is usable by
the profiling program <command>gprof</command>, although 
<command>gprof</command> will claim the values
are seconds, they really are instruction counts.  More on that later.
</para>

<para>
Because the SSP was originally designed to profile the cygwin DLL, it
does not automatically select a block of code to report statistics on.
You must specify the range of memory addresses to keep track of
manually, but it's not hard to figure out what to specify.  Use the
"objdump" program to determine the bounds of the target's ".text"
section.  Let's say we're profiling cygwin1.dll.  Make sure you've
built it with debug symbols (else <command>gprof</command> won't run) 
and run objdump like this:

<screen>
$ objdump -h cygwin1.dll
</screen>

It will print a report like this:
<screen>
cygwin1.dll:     file format pei-i386

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         0007ea00  61001000  61001000  00000400  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE, DATA
  1 .data         00008000  61080000  61080000  0007ee00  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  . . .
</screen>
</para>

<para>
The only information we're concerned with are the VMA of 
the .text section and the VMA of the section after it 
(sections are usually contiguous; you can also add the 
Size to the VMA to get the end address).  In this case, 
the VMA is 0x61001000 and the ending address is either 
0x61080000 (start of .data method) or 0x0x6107fa00 (VMA+Size
method).
</para>

<para>
There are two basic ways to use SSP - either profiling a whole
program, or selectively profiling parts of the program.
</para>

<para>
To profile a whole program, just run <command>ssp</command> without options.  
By default, it will step the whole program.  Here's a simple example, using 
the numbers above:

<screen>
$ ssp 0x61001000 0x61080000 hello.exe
</screen>

This will step the whole program.  It will take at least 8 minutes on
a PII/300 (yes, really).  When it's done, it will create a file called
"gmon.out".  You can turn this data file into a readable report with
<command>gprof</command>:

<screen>
$ gprof -b cygwin1.dll
</screen>

The "-b" means 'skip the help pages'.  You can omit this until you're
familiar with the report layout.  The <command>gprof</command> documentation 
explains a lot about this report, but <command>ssp</command> changes a few 
things.  For example, the first part of the report reports the amount of time 
spent in each function, like this:

<screen>
Each sample counts as 0.01 seconds.
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 10.02    231.22    72.43       46  1574.57  1574.57  strcspn
  7.95    288.70    57.48      130   442.15   442.15  strncasematch
</screen>

The "seconds" columns are really CPU opcodes, 1/100 second per opcode.
So, "231.22" above means 23,122 opcodes.  The ms/call values are 10x
too big; 1574.57 means 157.457 opcodes per call.  Similar adjustments
need to be made for the "self" and "children" columns in the second
part of the report.
</para>

<para>
OK, so now we've got a huge report that took a long time to generate,
and we've identified a spot we want to work on optimizing.  Let's say
it's the time() function.  We can use SSP to selectively profile this
function by using OutputDebugString() to control SSP from within the
program.  Here's a sample program:

<screen>
	#include &lt;windows.h&gt;
	main()
	{
	  time_t t;
	  OutputDebugString("ssp on");
	  time(&amp;t);
	  OutputDebugString("ssp off");
	}
</screen>
</para>

<para>
Then, add the <literal>-d</literal> option to ssp to default to 
*disabling* profiling.  The program will run at full speed until the first 
OutputDebugString, then step until the second.
You can then use <command>gprof</command> (as usual) to see the performance 
profile for just that portion of the program's execution.
</para>

<para>
There are many options to ssp.  Since step-profiling makes your
program run about 1,000 times slower than normal, it's best to
understand all the options so that you can narrow down the parts
of your program you need to single-step.
</para>

<para>
<literal>-v</literal> - verbose.  This prints messages about threads 
starting and stopping, OutputDebugString calls, DLLs loading, etc.
</para>

<para>
<literal>-t</literal> and <literal>-c</literal> - tracing.  
With <literal>-t</literal>, *every* step's address is written
to the file "trace.ssp".  This can be used to help debug functions,
since it can trace multiple threads.  Clever use of scripts can match
addresses with disassembled opcodes if needed.  Warning: creates
*huge* files, very quickly.  <literal>-c</literal> prints each address to 
the console, useful for debugging key chunks of assembler.  Use 
<literal>addr2line -C -f -s -e foo.exe &lt; trace.ssp &gt; lines.ssp</literal>
and then <literal>perl cvttrace</literal> to convert to symbolic traces.
</para>

<para>
<literal>-s</literal> - subthreads.  Usually, you only need to trace the 
main thread, but sometimes you need to trace all threads, so this enables that.
It's also needed when you want to profile a function that only a
subthread calls.  However, using OutputDebugString automatically
enables profiling on the thread that called it, not the main thread.
</para>

<para>
<literal>-l</literal> - dll profiling.  Generates a pretty table of how much 
time was spent in each dll the program used.  No sense optimizing a function in
your program if most of the time is spent in the DLL.
I usually use the <literal>-v</literal>, <literal>-s</literal>, and 
<literal>-l</literal> options:

<screen>
$ ssp <literal>-v</literal> <literal>-s</literal> <literal>-l</literal> <literal>-d</literal> 0x61001000 0x61080000 hello.exe
</screen>
</para>
</sect2>

<sect2 id="strace"><title>strace</title>

<screen>
Usage: strace.exe [OPTIONS] &lt;command-line&gt;
Usage: strace.exe [OPTIONS] -p &lt;pid&gt;
Trace system calls and signals

  -b, --buffer-size=SIZE       set size of output file buffer
  -d, --no-delta               don't display the delta-t microsecond timestamp
  -f, --trace-children         trace child processes (toggle - default true)
  -h, --help                   output usage information and exit
  -m, --mask=MASK              set message filter mask
  -n, --crack-error-numbers    output descriptive text instead of error
                               numbers for Windows errors
  -o, --output=FILENAME        set output file to FILENAME
  -p, --pid=n                  attach to executing program with cygwin pid n
  -q, --quiet                  toggle "quiet" flag.  Defaults to on if "-p",
                               off otherwise.
  -S, --flush-period=PERIOD    flush buffered strace output every PERIOD secs
  -t, --timestamp              use an absolute hh:mm:ss timestamp insted of 
                               the default microsecond timestamp.  Implies -d
  -T, --toggle                 toggle tracing in a process already being
  -u, --usecs                  toggle printing of microseconds timestamp
                               traced. Requires -p &lt;pid&gt;
  -v, --version                output version information and exit
  -w, --new-window             spawn program under test in a new window

    MASK can be any combination of the following mnemonics and/or hex values
    (0x is optional).  Combine masks with '+' or ',' like so:

                      --mask=wm+system,malloc+0x00800

    Mnemonic Hex     Corresponding Def  Description
    =========================================================================
    all      0x000001 (_STRACE_ALL)      All strace messages.
    flush    0x000002 (_STRACE_FLUSH)    Flush output buffer after each message.
    inherit  0x000004 (_STRACE_INHERIT)  Children inherit mask from parent.
    uhoh     0x000008 (_STRACE_UHOH)     Unusual or weird phenomenon.
    syscall  0x000010 (_STRACE_SYSCALL)  System calls.
    startup  0x000020 (_STRACE_STARTUP)  argc/envp printout at startup.
    debug    0x000040 (_STRACE_DEBUG)    Info to help debugging. 
    paranoid 0x000080 (_STRACE_PARANOID) Paranoid info.
    termios  0x000100 (_STRACE_TERMIOS)  Info for debugging termios stuff.
    select   0x000200 (_STRACE_SELECT)   Info on ugly select internals.
    wm       0x000400 (_STRACE_WM)       Trace Windows msgs (enable _strace_wm).
    sigp     0x000800 (_STRACE_SIGP)     Trace signal and process handling.
    minimal  0x001000 (_STRACE_MINIMAL)  Very minimal strace output.
    pthread  0x002000 (_STRACE_PTHREAD)	Pthread calls.
    exitdump 0x004000 (_STRACE_EXITDUMP) Dump strace cache on exit.
    system   0x008000 (_STRACE_SYSTEM)   Serious error; goes to console and log.
    nomutex  0x010000 (_STRACE_NOMUTEX)  Don't use mutex for synchronization.
    malloc   0x020000 (_STRACE_MALLOC)   Trace malloc calls.
    thread   0x040000 (_STRACE_THREAD)   Thread-locking calls.
    special  0x100000 (_STRACE_SPECIAL)  Special debugging printfs for
                                         non-checked-in code
</screen>

<para>The <command>strace</command> program executes a program, and
optionally the children of the program, reporting any Cygwin DLL output
from the program(s) to stdout, or to a file with the <literal>-o</literal>
option.  With the <literal>-w</literal> option, you can start an strace
session in a new window, for example:

<screen>
$ strace -o tracing_output -w sh -c 'while true; do echo "tracing..."; done' &amp;
</screen>
This is particularly useful for <command>strace</command> sessions that
take a long time to complete.
</para>

<para>
Note that <command>strace</command> is a standalone Windows program and so does 
not rely on the Cygwin DLL itself (you can verify this with 
<command>cygcheck</command>). As a result it does not understand symlinks.
This program is mainly useful for debugging the Cygwin DLL itself.</para>

</sect2>

<sect2 id="umount"><title>umount</title>

<screen>
Usage: umount.exe [OPTION] [&lt;posixpath&gt;]
Unmount filesystems

  -h, --help                    output usage information and exit
  -U, --remove-user-mounts      remove all user mounts
  -v, --version                 output version information and exit
</screen>

<para>The <command>umount</command> program removes mounts from the
mount table in the current session.  If you specify a POSIX path that
corresponds to a current mount point, <command>umount</command> will
remove it from the current mount table.  Note that you can only remove
user mount points.  The <literal>-U</literal> flag may be used to
specify removing all user mount points from the current user session.</para>

<para>See <xref linkend="mount-table"></xref> for more information on the mount
table.</para>
</sect2>

</sect1>