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newlib/winsup/utils/utils.sgml
Christopher Faylor 801d6cc753 * strace.cc (show_usecs): Renamed from 'usecs'. 
(main): Use show_usecs rather than usecs.  Toggle delta if '-u' is specified.
(handle_output_debug_string): Avoid printing microsecond timestamp if
show_usecs == 0.
* utils.sgml (strace): Add words to describe '-u'.
2005-12-05 16:39:06 +00:00

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<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 PROGRAM [ -v ] [ -h ]
cygcheck -c [ PACKAGE ... ] [ -d ]
cygcheck -s [ -r ] [ -v ] [ -h ]
cygcheck -k
cygcheck -f FILE [ FILE ... ]
cygcheck -l [ PACKAGE ... ]
cygcheck -p REGEXP
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 that FILE belongs to
-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 (requies internet connectivity)
-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><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><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>C:\cygwin&gt;</prompt> <userinput>cygcheck -s -v -r -h &gt; cygcheck_output.txt</userinput>
</screen>
</sect2>
<sect2 id="cygpath"><title>cygpath</title>
<screen>
Usage: cygpath (-d|-m|-u|-w|-t TYPE) [-f FILE] [OPTION]... NAME...
cygpath [-c HANDLE]
cygpath [-ADHPSW]
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)
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
-P, --smprograms output Start Menu `Programs' directory and exit
-S, --sysdir output system directory and exit
-W, --windir output `Windows' directory 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>Caveat: The <literal>-l</literal> option does not work if the
<emphasis>check_case</emphasis> parameter of <emphasis>CYGWIN</emphasis>
is set to <emphasis>strict</emphasis>, since Cygwin is not able to match
any Windows short path in this mode.
</para>
<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><title>Example <command>cygpath</command> usage</title>
<screen>
<![CDATA[
#!/bin/sh
if [ "${1}" = "" ];
then
XPATH=".";
else
XPATH="$(cygpath -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\SYSTEM.
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> and <literal>-P</literal> options.
On Win9x systems with only a single user, <literal>-A</literal> has no
effect; <literal>-D</literal> and <literal>-AD</literal> would have the
same output. 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
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), like these examples:</para>
<example><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
SIGTTIN 21 to readers pgrp upon background tty read
SIGTTOU 22 like TTIN for output if (tp-&gt;t_local&amp;LTOSTOP)
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)
SIGUSR1 30 user defined signal 1
SIGUSR2 31 user defined signal 2
</screen>
</sect2>
<sect2 id="mkgroup"><title>mkgroup</title>
<screen>
Usage: mkgroup [OPTION]... [domain]...
Prints /etc/group file to stdout
Options:
-l,--local print local group information
-c,--current print current group, if a domain account
-d,--domain print global group information (from current
domain if no domains specified).
-o,--id-offset offset change the default offset (10000) added to gids
in domain accounts.
-s,--no-sids don't print SIDs in pwd field
(this affects ntsec)
-u,--users print user list in gr_mem field
-g,--group groupname only return information for the specified group\n");
-h,--help print this message
-v,--version print version information and exit
One of `-l' or `-d' must be given on NT/W2K.
</screen>
<para>The <command>mkgroup</command> program can be used to help
configure your Windows system to be more UNIX-like by creating an
initial <filename>/etc/group</filename>.
Its use is essential on the NT series (Windows NT, 2000, and XP) to
include Windows security information.
It can also be used on the Win9x series (Windows 95, 98, and Me) to
create a file with the correct format.
To initially set up your machine if you are a local user, you'd do
something like this:</para>
<example><title>Setting up the groups file for local accounts</title>
<screen>
<prompt>$</prompt> <userinput>mkdir /etc</userinput>
<prompt>$</prompt> <userinput>mkgroup -l &gt; /etc/group</userinput>
</screen>
</example>
<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</literal> and <literal>-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</literal> option the program contacts the Domain
Controller, which my be unreachable or have restricted access.
An entry for the current domain user can then be created by using the
option <literal>-c</literal> together with <literal>-l</literal>,
but <literal>-c</literal> has no effect when used with <literal>-d</literal>.
The <literal>-o</literal> option allows for special cases
(such as multiple domains) where the GIDs might match otherwise.
The <literal>-s</literal>
option omits the NT Security Identifier (SID). For more information on
SIDs, see <xref linkend="ntsec"></xref> in the Cygwin User's Guide. The
<literal>-u</literal> option causes <command>mkgroup</command> to
enumerate the users for each group, placing the group members in the
gr_mem (last) field. Note that this can greatly increase
the time for <command>mkgroup</command> to run in a large domain.
Having gr_mem fields is helpful when a domain user logs in remotely
while the local machine is disconnected from the Domain Controller.
The <literal>-g</literal> option only prints the information for
one group.
</para>
</sect2>
<sect2 id="mkpasswd"><title>mkpasswd</title>
<screen>
Usage: mkpasswd [OPTION]... [domain]...
Prints /etc/passwd file to stdout
Options:
-l,--local print local user accounts
-c,--current print current account, if a domain account
-d,--domain print domain accounts (from current domain
if no domains specified)
-o,--id-offset offset change the default offset (10000) added to uids
in domain accounts.
-g,--local-groups print local group information too
if no domains specified
-m,--no-mount don't use mount points for home dir
-s,--no-sids don't print SIDs in GCOS field
(this affects ntsec)
-p,--path-to-home path use specified path and not user account home dir or /home
-u,--username username only return information for the specified user
-h,--help displays this message
-v,--version version information and exit
One of `-l', `-d' or `-g' must be given on NT/W2K.
</screen>
<para>The <command>mkpasswd</command> program can be used to help
configure your Windows system to be more UNIX-like by creating an
initial <filename>/etc/passwd</filename> from your system information.
Its use is essential on the NT series (Windows NT, 2000, and XP) to
include Windows security information, but the actual passwords are
determined by Windows, not by the content of <filename>/etc/passwd</filename>.
On the Win9x series (Windows 95, 98, and Me) the password field must be
replaced by the output of <userinput>crypt your_password</userinput>
if remote access is desired.
To initially set up your machine if you are a local user, you'd do
something like this:</para>
<example><title>Setting up the passwd file for local accounts</title>
<screen>
<prompt>$</prompt> <userinput>mkdir /etc</userinput>
<prompt>$</prompt> <userinput>mkpasswd -l &gt; /etc/passwd</userinput>
</screen>
</example>
<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</literal> and <literal>-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</literal> option the program contacts the Domain
Controller, which my be unreachable or have restricted access.
An entry for the current domain user can then be created by using the
option <literal>-c</literal> together with <literal>-l</literal>,
but <literal>-c</literal> has no effect when used with <literal>-d</literal>.
The <literal>-o</literal> option allows for special cases
(such as multiple domains) where the UIDs might match otherwise.
The <literal>-g</literal> option creates a local
user that corresponds to each local group. This is because NT assigns groups
file ownership. 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. The <literal>-s</literal>
option omits the NT Security Identifier (SID). 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><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.
On Win9x machines the <literal>-u</literal> option creates an entry for
the specified user. On the NT series it restricts the output to that user,
greatly reducing the amount of time it takes in a large domain.</para>
</sect2>
<sect2 id="mount"><title>mount</title>
<screen>
Usage: mount [OPTION] [&lt;win32path&gt; &lt;posixpath&gt;]
Display information about mounted filesystems, or mount a filesystem
-b, --binary (default) text files are equivalent to binary files
(newline = \n)
-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-commands write mount commands to replicate user and
system mount points and cygdrive prefixes
-o, --options X[,X...] specify mount options
-p, --show-cygdrive-prefix show user and/or system cygdrive path prefix
-s, --system (default) add system-wide mount point
-t, --text text files get \r\n line endings
-u, --user add user-only mount point
-v, --version output version information and exit
-x, --executable treat all files under mount point as executables
-E, --no-executable treat all files under mount point as
non-executables
-X, --cygwin-executable treat all files under mount point as cygwin
executables
</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. 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, use <command>umount</command></para>
<sect3><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>
<title>Displaying the current set of mount points</title>
<screen>
<prompt>c:\cygwin\&gt;</prompt> <userinput>mount</userinput>
c:\cygwin\bin on /usr/bin type system (binmode)
c:\cygwin\lib on /usr/lib type system (binmode)
c:\cygwin on / type system (binmode)
c: on /c type user (binmode,noumount)
d: on /d type user (binmode,noumount)
</screen>
</example>
<para>In this example, c:\cygwin is the POSIX root and D drive is mapped to
<filename>/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>/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. The following example
demonstrates how to mount the directory
<filename>\\pollux\home\joe\data</filename> to <filename>/data</filename>.
</para>
<example>
<title>Adding mount points</title>
<screen>
<prompt>c:\cygwin\&gt;</prompt> <userinput>ls /data</userinput>
ls: /data: No such file or directory
<prompt>c:\cygwin\&gt;</prompt> <userinput>mount \\pollux\home\joe\data /data</userinput>
mount: warning - /data does not exist!
<prompt>c:\cygwin\&gt;</prompt> <userinput>mount</userinput>
\\pollux\home\joe\data on /data type sytem (binmode)
c:\cygwin\bin on /usr/bin type system (binmode)
c:\cygwin\lib on /usr/lib type system (binmode)
c:\cygwin on / type system (binmode)
c: on /c type user (binmode,noumount)
d: on /d type user (binmode,noumount)
</screen>
</example>
<para>Note that <command>mount</command> was invoked from the Windows
command shell in the previous example. In many Unix shells, including
bash, it is legal and convenient to use the forward "/" in Win32
pathnames since the "\" is the shell's escape character. </para>
<para>The <literal>-s</literal> flag to <command>mount</command> is used to add a mount
in the system-wide mount table used by all Cygwin users on the system,
instead of the user-specific one. System-wide mounts are displayed
by <command>mount</command> as being of the "system" type, as is the
case for the <filename>/</filename> partition in the last example.
Under Windows NT, only those users with Administrator priviledges are
permitted to modify the system-wide mount table.</para>
<para>Note that a given POSIX path may only exist once in the user
table and once in the global, system-wide table. Attempts to replace
the mount will fail with a busy error. The <literal>-f</literal> (force) flag causes
the old mount to be silently replaced with the new one. It will also
silence warnings about the non-existence of directories at the Win32
path location.</para>
<para>The <literal>-b</literal> flag is used to instruct Cygwin to treat binary and
text files in the same manner by default. Binary mode mounts are
marked as "binmode" in the Flags column of <command>mount</command>
output. By default, mounts are in text mode ("textmode" in the Flags
column).</para>
<para>Normally, files ending in certain extensions (.exe, .com, .bat, .cmd)
are assumed to be executable. Files whose first two characters begin with
'#!' are also considered to be executable.
The <literal>-x</literal> flag is used to instruct Cygwin that the
mounted file is "executable". If the <literal>-x</literal> flag is used
with a directory then all files in the directory are executable.
This option allows other files to be marked as executable and avoids the
overhead of opening each file to check for a '#!'. The <literal>-X</literal>
option is very similar to <literal>-x</literal>, but also prevents Cygwin
from setting up commands and environment variables for a normal Windows
program, adding another small performance gain. The opposite of these
flags is the <literal>-E</literal> flag, which means that no files should be
marked as executable. </para>
<para>
The <literal>-m</literal> option causes the <command>mount</command> utility
to output a series of commands that could recreate both user and system mount
points. You can save this output as a backup when experimenting with the
mount table. It also makes moving your settings to a different machine
much easier.
</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>
user - mount lives user-specific mount
system - mount lives in system table (default)
binary - files default to binary mode (default)
text - files default to CRLF text mode line endings
exec - files below mount point are all executable
notexec - files below mount point are not executable
cygexec - files below mount point are all cygwin executables
nosuid - no suid files are allowed (currently unimplemented)
managed - directory is managed by cygwin. Mixed case and special
characters in filenames are allowed.
</screen>
</sect3>
<sect3><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>/</filename>:</para>
<example>
<title>Changing the default prefix</title>
<screen>
<prompt>c:\cygwin\&gt;</prompt> <userinput>mount --change-cygdrive-prefix /</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. Use the <literal>-s</literal>
or <literal>-u</literal> flag to indicate a system or user mount, respectively.
You can always see the user and system cygdrive prefixes with the
<literal>-p</literal> option. Using the <literal>-b</literal>
flag with <literal>--change-cygdrive-prefix</literal> makes all new
automounted filesystems default to binary mode file accesses.</para>
</sect3>
<sect3><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.
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:
-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.
</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>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
-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>-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.exe [OPTION] (add | check | get | list | remove | unset) 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
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 'set' Action:
-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
-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
-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>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 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>set</literal> action sets a value within a key.
<literal>-e</literal> means it's an expanding string (REG_EXPAND_SZ)
that contains embedded environment variables.
<literal>-i</literal> means the value is an integer (REG_DWORD).
<literal>-m</literal> means it's a multi-string (REG_MULTI_SZ).
<literal>-s</literal> means the value is a string (REG_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. 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.
The <literal>unset</literal> action removes a value from a key.
</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
-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 0x00001 (_STRACE_ALL) All strace messages.
flush 0x00002 (_STRACE_FLUSH) Flush output buffer after each message.
inherit 0x00004 (_STRACE_INHERIT) Children inherit mask from parent.
uhoh 0x00008 (_STRACE_UHOH) Unusual or weird phenomenon.
syscall 0x00010 (_STRACE_SYSCALL) System calls.
startup 0x00020 (_STRACE_STARTUP) argc/envp printout at startup.
debug 0x00040 (_STRACE_DEBUG) Info to help debugging.
paranoid 0x00080 (_STRACE_PARANOID) Paranoid info.
termios 0x00100 (_STRACE_TERMIOS) Info for debugging termios stuff.
select 0x00200 (_STRACE_SELECT) Info on ugly select internals.
wm 0x00400 (_STRACE_WM) Trace Windows msgs (enable _strace_wm).
sigp 0x00800 (_STRACE_SIGP) Trace signal and process handling.
minimal 0x01000 (_STRACE_MINIMAL) Very minimal strace output.
exitdump 0x04000 (_STRACE_EXITDUMP) Dump strace cache on exit.
system 0x08000 (_STRACE_SYSTEM) Serious error; goes to console and log.
nomutex 0x10000 (_STRACE_NOMUTEX) Don't use mutex for synchronization.
malloc 0x20000 (_STRACE_MALLOC) Trace malloc calls.
thread 0x40000 (_STRACE_THREAD) Thread-locking calls.
</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
-A, --remove-all-mounts remove all mounts
-c, --remove-cygdrive-prefix remove cygdrive prefix
-h, --help output usage information and exit
-s, --system remove system mount (default)
-S, --remove-system-mounts remove all system mounts
-u, --user remove user mount
-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. If you specify a POSIX path that corresponds to a
current mount point, <command>umount</command> will remove it from the
system registry area. (Administrator priviledges are required).
The <literal>-u</literal> flag may be used to specify removing the mount
from the user-specific registry area instead.</para>
<para>The <command>umount</command> utility may also be used to remove
all mounts of a particular type. With the extended options it is
possible to remove all mounts (<literal>-A</literal>), all
cygdrive automatically-mounted mounts (<literal>-c</literal>), all
mounts in the current user's registry area (<literal>-U</literal>),
or all mounts in the system-wide registry area (<literal>-S</literal>)
(with Administrator privileges).</para>
<para>See <xref linkend="mount"></xref> for more information on the mount
table.</para>
</sect2>
</sect1>
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