Cygwin Utilities
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, --help and
-h function identically. All of the Cygwin
command-line utilities support the --help and
--version options.
cygcheck
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.
The cygcheck program is a diagnostic utility for
dealing with Cygwin programs. If you are familiar with
dpkg or rpm,
cygcheck is similar in many ways. (The major difference
is that setup.exe handles installing and uninstalling
packages; see for more information.)
The -c option checks the version and status of
installed Cygwin packages. If you specify one or more package names,
cygcheck will limit its output to those packages,
or with no arguments it lists all packages. A package will be marked
Incomplete if files originally installed are no longer
present. The best thing to do in that situation is reinstall the package
with setup.exe. To see which files are missing, use the
-v option. If you do not need to know the status
of each package and want cygcheck to run faster, add the
-d option and cygcheck will only
output the name and version for each package.
If you list one or more programs on the command line,
cygcheck 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 -s option,
cygcheck will give general system information. If you
list one or more programs on the command line and specify
-s, cygcheck will report on
both.
The -f option helps you to track down which package a
file came from, and -l lists all files in a package.
For example, to find out about /usr/bin/less and its
package:
Example cygcheck usage
$ 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
The -h 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.
The -v 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.
The -r option causes
cygcheck 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.
In contrast to the other options that search the packages that are
installed on your local system, the -p 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
cygwin.com web site. In fact, it is equalivant to the
search that is available on the Cygwin
package listing page.
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:
Searching all packages for a file
$ 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)
Note that this option takes a regular expression, not a glob or wildcard.
This means that you need to use .* if you want something
similar to the wildcard * commonly used in filename globbing.
Similarly, to match the period character you should use \.
since the . character in a regexp is a metacharacter that
will match any character. Also be aware that the characters such as
\ and * are shell metacharacters, so
they must be either escaped or quoted, as in the example above.
The third example above illustrates that if you want to match a whole
filename, you should include the / path seperator. In the
given example this ensures that filenames that happen to end in
ls.exe such as ncftpls.exe are not shown.
Note that this use does not mean "look for packages with ls
in the root directory," since the / can match anywhere in the
path. It's just there to anchor the match so that it matches a full
filename.
By default the matching is case-sensitive. To get a case insensitive
match, begin your regexp with (?i) which is a PCRE-specific
feature. For complete documentation on Perl-compatible regular expression
syntax and options, read the perlre manpage, or one of many
websites such as perldoc.com that document the Perl
language.
The cygcheck 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:
$ cygcheck -s -v -r -h > cygcheck_output.txt
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 cygcheck --delete-orphaned-installation-keys
command.
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.
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:
*** 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.
To disable the usage of a unique key value of a certain Cygwin DLL, use
the cygcheck --disable-unique-object-names Cygwin-DLL
command. Cygwin-DLL 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
cygcheck from a DOS command line for this purpose.
To re-enable the usage of a unique key, use the
cygcheck --enable-unique-object-names Cygwin-DLL command.
This option has the same characteristics as the
--disable-unique-object-names option
Finally, you can use
cygcheck --show-unique-object-names Cygwin-DLL to find out
if the given Cygwin DLL use unique object names or not. In contrast to the
--disable-... and --enable-... options,
the --show-unique-object-names option also works for
Cygwin DLLs which are currently in use.
cygpath
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
The cygpath 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, cygpath can
output information about the location of important system directories
in either format.
The -u and -w options
indicate whether you want a conversion to UNIX (POSIX) format
(-u) or to Windows format (-w).
Use the -d to get DOS-style (8.3) file and path names.
The -m 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.
In combination with the -w option, you can use
the -l and -s options to use normal
(long) or DOS-style (short) form. The -d option is
identical to -w and -s together.
The -C option allows to specify a Windows codepage
to print DOS and Windows paths created with one of the -d,
-m, or -w options. The default is to
use the character set of the current locale defined by one of the
internationalization environment variables LC_ALL,
LC_CTYPE, or LANG, see
. 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.
The -C option takes a single parameter:
ANSI, to specify the current ANSI codepage
OEM, to specify the current OEM (console) codepage
UTF8, to specify UTF-8.
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
Code Page Identifiers. A codepage of 0 is the same as if the
-C hasn't been specified at all.
The -p 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 -p you are
instructing cygpath to convert between these
formats.
The -i 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 cygpath output may
contain spaces (C:\Program Files) so should be enclosed in quotes.
Example cygpath usage
The capital options
-D, -H, -P,
-S, and -W output directories used
by Windows that are not the same on all systems, for example
-S might output C:\WINNT\system32 or C:\Windows\System32.
The -H shows the Windows profiles directory that can
be used as root of home. The -A option forces use of
the "All Users" directories instead of the current user for the
-D, -O and -P
options.
The -F 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 -w or -d options to get
other formats.
dumper
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
The dumper utility can be used to create a
core dump of running Windows process. This core dump can be later loaded
to gdb and analyzed. One common way to use
dumper is to plug it into cygwin's Just-In-Time
debugging facility by adding
error_start=x:\path\to\dumper.exe
to the CYGWIN environment variable. Please note that
x:\path\to\dumper.exe is Windows-style and not cygwin
path. If error_start is set this way, then dumper will
be started whenever some program encounters a fatal error.
dumper 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 dumper
exits, the target process is terminated too.
To save space in the core dump, dumper 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,
dumper 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.
getfacl
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.
For each argument that is a regular file, special file or
directory, getfacl displays the owner, the group, and the
ACL. For directories getfacl displays additionally the
default ACL. With no options specified, getfacl 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
in the Cygwin User's Guide.
The format for ACL output is as follows:
# 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
getlocale
Usage: getlocale [-asuh]
Print Windows locale(s)
Options:
-a, --all List all available locales
-s, --system Print system default locale
(default is current user default locale)
-u, --utf Attach ".UTF-8" to the result
-h, --help this text
getlocale without parameters just prints the
current user's Windows default locale to stdout. The -s
option prints the systems default locale instead. With the
-u option getlocale appends a ".UTF-8".
This can be used in scripts to set the Cygwin locale, for instance:
bash$ export LANG=$(getlocale -u)
bash$ echo $LANG
en_US.UTF-8
The -a option is helpful to learn which locales
are supported by your Windows machine. It prints the locales and their
actual meaning, like this:
bash$ getlocale -a
ar_SA Arabic (Saudi Arabia)
ar_IQ Arabic (Iraq)
zh_TW Chinese (Traditional) (Taiwan)
zh_CN Chinese (Simplified) (People's Republic of China)
zh_HK Chinese (Traditional) (Hong Kong S.A.R.)
da_DK Danish (Denmark)
en_US English (United States)
en_GB English (United Kingdom)
en_AU English (Australia)
...
kill
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
The kill 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.
You may need to specify the full path to use kill
from within some shells, including bash, the default Cygwin
shell. This is because bash defines a
kill builtin function; see the bash
man page under BUILTIN COMMANDS for more information.
To make sure you are using the Cygwin version, try
$ /bin/kill --version
which should give the Cygwin kill version number and
copyright information.
Unless you specific the -f option, the "pid" values
used by kill are the Cygwin pids, not the Windows pids.
To get a list of running programs and their Cygwin pids, use the Cygwin
ps program. ps -W will display
all windows pids.
The kill -l option prints the name of the
given signal, or a list of all signal names if no signal is given.
To send a specific signal, use the -signN
option, either with a signal number or a signal name (minus the "SIG"
part), as shown in these examples:
Using the kill command
$ kill 123
$ kill -1 123
$ kill -HUP 123
$ kill -f 123
Here is a list of available signals, their numbers, and some
commentary on them, from the file
<sys/signal.h>, which should be considered
the official source of this information.
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->t_local<OSTOP)
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
mkgroup
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.
The mkgroup program can be used to help
configure Cygwin by creating a /etc/group
file. Its use is essential to include Windows security information.
The command is initially called by setup.exe to
create a default /etc/group. This should be
sufficient in most circumstances. However, especially when working
in a multi-domain environment, you can use mkgroup
manually to create a more complete /etc/group file for
all domains. Especially when you have the same group name used on
multiple machines or in multiple domains, you can use the -D,
-L and -C options to create unique
domain\group style groupnames.
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.
The -d/-D and -l/-L options
allow you to specify where the information comes from, the
local SAM of a machine or from the domain, or both.
With the -d/-D 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 mkgroup.
For very simple needs, an entry for the current user's group can be
created by using the option -c or -C.
If you want to use one of the -D, -L
or -C options, but you don't like the backslash as
domain/group separator, you can specify another separator using the
-S option, for instance:
Setting up group entry for current user with different domain/group separator
$ mkgroup -C -S+ > /etc/group
$ cat /etc/group
DOMAIN+my_group:S-1-5-21-2913048732-1697188782-3448811101-1144:11144:
The -o option allows for special cases
(such as multiple domains) where the GIDs might match otherwise.
The -g option only prints the information for one group.
The -U option allows you to enumerate the standard UNIX
groups on a Samba machine. It's used together with
-l samba-server or -L samba-server.
The normal UNIX groups are usually not enumerated, but they can show
up as a group in ls -l output.
mkpasswd
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.
The mkpasswd program can be used to help
configure Cygwin by creating a /etc/passwd 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
/etc/passwd.
The command is initially called by setup.exe to
create a default /etc/passwd. This should be
sufficient in most circumstances. However, especially when working
in a multi-domain environment, you can use mkpasswd
manually to create a more complete /etc/passwd file for
all domains. Especially when you have the same user name used on
multiple machines or in multiple domains, you can use the -D,
-L and -C options to create unique
domain\user style usernames.
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.
The -d/-D and -l/-L options
allow you to specify where the information comes from, the
local machine or the domain (default or given), or both.
With the -d/-D 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 mkpasswd.
An entry for the current user can be created by using the
option -c or -C.
If you want to use one of the -D, -L
or -C options, but you don't like the backslash as
domain/group separator, you can specify another separator using the
-S option, similar to the mkgroup.
The -o option allows for special cases
(such as multiple domains) where the UIDs might match otherwise.
The -m 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 in the Cygwin User's Guide. The
-p option causes mkpasswd to
use the specified prefix instead of the account home dir or /home/
. For example, this command:
Using an alternate home root
$ mkpasswd -l -p "$(cygpath -H)" > /etc/passwd
would put local users' home directories in the Windows 'Profiles' directory.
The -u option creates just an entry for
the specified user.
The -U option allows you to enumerate the standard UNIX
users on a Samba machine. It's used together with
-l samba-server or -L samba-server.
The normal UNIX users are usually not enumerated, but they can show
up as file owners in ls -l output.
mount
Usage: mount [OPTION] [<win32path> <posixpath>]
mount -a
mount <posixpath>
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 <posixpath>
-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
The mount 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 /etc/fstab, mount points
created or changed with mount are not persistent. They
disappear immediately after the last process of the current user exited.
Please see for more information on the
concepts behind the Cygwin POSIX file system and strategies for using
mounts. To remove mounts temporarily, use umount
Using mount
If you just type mount with no parameters, it
will display the current mount table for you.
Displaying the current set of mount points
$ mount
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)
In this example, c:\cygwin is the POSIX root and D drive is mapped to
/d. 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 /d mount is only visible
to the current user.
The mount utility is also the mechanism for
adding new mounts to the mount table. The following example
demonstrates how to mount the directory
//pollux/home/joe/data to /data
for the duration of the current session.
Adding mount points
$ ls /data
ls: /data: No such file or directory
$ mount //pollux/home/joe/data /data
mount: warning - /data does not exist!
$ mount
//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)
A given POSIX path may only exist once in the mount table. Attempts to
replace the mount will fail with a busy error. The -f
(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 -f
option will silence warnings about the non-existence of directories at the
Win32 path location.
The -o 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):
acl - Use the filesystem's access control lists (ACLs) to
implement real POSIX permissions (default).
binary - Files default to binary mode (default).
cygexec - Treat all files below mount point as cygwin executables.
exec - Treat all files below mount point as executable.
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.
For a more complete description of the mount options and the
/etc/fstab file, see
.
Note that all mount points added with mount are
user mount points. System mount points can only be specified in
the /etc/fstab file.
If you added mount points to /etc/fstab or your
/etc/fstab.d/<username> file, you can add these
mount points to your current user session using the -a/--all
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
/my/mount. You can add this mount point with either
one of the following two commands to your current user session.
$ mount /my/mount
$ mount -a
The first command just adds the /my/mount mount
point to your current session, the mount -a adds all
new mount points to your user session.
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 umount
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.
The -m option causes the mount 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 /etc/fstab to restore the old state.
It also makes moving your settings to a different machine much easier.
Cygdrive mount points
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:
/cygdrive. For example, if Cygwin accesses
z:\foo and the z drive is not currently in the
mount table, then z:\ will be accessible as
/cygdrive/z. The mount 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 /mnt:
Changing the default prefix
$ mount --change-cygdrive-prefix /mnt
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 mount 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
-p option. Using the --options
flag with --change-cygdrive-prefix makes all new
automounted filesystems default to this set of options. For instance
(using the short form of the command line flags)
Changing the default prefix with specific mount options
$ mount -c /mnt -o binary,noacl
Limitations
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.
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.
It is sometimes desirable to mount to a non-existent directory,
for example to avoid cluttering the root directory with names
such as
a, b, c
pointing to disks.
Although mount 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
/dir,
say, and /dir/mtpt is a mount point, then
mtpt will not show up in an ls
or
echo * command and find . will
not
find mtpt.
passwd
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.
passwd 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.
passwd also changes account information, such as
password expiry dates and intervals.
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.
The user is then prompted for a replacement password.
passwd 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.
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, passwd refuses to change the
password and exits.
To get current password status information, use the
-S option. Administrators can use
passwd to perform several account maintenance
functions (users may perform some of these functions on their own
accounts). Accounts may be locked with the -l flag
and unlocked with the -u flag. Similarly,
-c disables a user's ability to change passwords, and
-C allows a user to change passwords. For password
expiry, the -e option disables expiration, while the
-E option causes the password to expire according to
the system's normal aging rules. Use -p to disable
the password requirement for a user, or -P to require
a password.
Administrators can also use passwd to change
system-wide password expiry and length requirements with the
-i, -n, -x,
and -L options. The -i
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 NUM days, the user may no longer sign on to
the account. The -n 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
MINDAYS days have elapsed. The
-x option is used to set the maximum number of days
a password remains valid. After MAXDAYS days, the
password is required to be changed. Allowed values for the above options
are 0 to 999. The -L option sets the minimum length of
allowed passwords for users who don't belong to the administrators group
to LEN 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'.
All operations affecting the current user are by default run against
the logon server of the current user (taken from the environment
variable LOGONSERVER. 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 -d
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.
Users can use the passwd -R 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
set{e}uid(user_id) 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, ssh 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
.
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 passwd -R, it's required to run
cygserver as a service under the LocalSystem account
before running passwd -R. This only affects storing
passwords. Using passwords in privileged processes does not require
cygserver to run.
Limitations: Users may not be able to change their password on
some systems.
ps
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
The ps 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.
The PID column is the process ID you need to give to the
kill 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 '?'
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; S means stopped or suspended (in other
words, in the background), I means waiting for
input or interactive (foreground), and O means
waiting to output.
By default, ps will only show processes owned by the
current user. With either the -a or -e
option, all user's processes (and system processes) are listed. There are
historical UNIX reasons for the synonomous options, which are functionally
identical. The -f option outputs a "full" listing with
usernames for UIDs. The -l option is the default display
mode, showing a "long" listing with all the above columns. The other display
option is -s, which outputs a shorter listing of just
PID, TTY, STIME, and COMMAND. The -u option allows you
to show only processes owned by a specific user. The -p
option allows you to show information for only the process with the
specified PID. The -W
option causes ps show non-Cygwin Windows processes as
well as Cygwin processes. The WINPID is also the PID, and they can be killed
with the Cygwin kill command's -f
option.
regtool
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<c>, --key-separator[=]<c> set key separator to <c> 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'
The regtool 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.
The -v option means "verbose". For most
commands, this causes additional or lengthier messages to be printed.
Conversely, the -q option supresses error messages,
so you can use the exit status of the program to detect if a key
exists or not (for example).
The -w 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 -w switch, the 64 bit view is used and
regtool can access the entire registry.
This option is simply ignored when running on 32 bit Windows versions.
The -W 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.
You must provide regtool with an
action following options (if any). Currently,
the action must be add, set,
check, get, list,
remove, set, or unset.
The add action adds a new key. The
check 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 get 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 -q, it doesn't
print the message but does return the non-zero exit code.
The list action lists the subkeys and values
belonging to the given key. With list, the
-k option instructs regtool
to print only KEYs, and the -l option to print
only VALUEs. The -p option postfixes a
'/' to each KEY, but leave VALUEs with no
postfix. The remove 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.
The get action prints a value within a key.
With the -b option, data is printed as hex bytes.
-n allows to print the data as a typeless stream of
bytes. Integer values (REG_DWORD, REG_QWORD) are usually printed
as decimal values. The -x option allows to print
the numbers as hexadecimal values.
The set action sets a value within a key.
-b means it's binary data (REG_BINARY).
The binary values are specified as hex bytes in the argument list.
If the argument is '-', binary data is read
from stdin instead.
-d or -i means the value is a 32 bit
integer value (REG_DWORD).
-D means the value is a 32 bit integer value in
Big Endian representation (REG_DWORD_BIG_ENDIAN).
-Q means the value is a 64 bit integer value (REG_QWORD).
-s means the value is a string (REG_SZ).
-e means it's an expanding string (REG_EXPAND_SZ)
that contains embedded environment variables.
-m means it's a multi-string (REG_MULTI_SZ).
If you don't specify one of these, regtool 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.
The unset action removes a value from a key.
The load 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 unload action unloads the file and removes
the subkey.
The save action saves a subkey into a
registry hive.
By default, the last "\" or "/" is assumed to be the separator between the
key and the value. You can use the -K option to provide
an alternate key/value separator character.
setfacl
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
For each file given as parameter, setfacl will
either replace its complete ACL (-s, -f),
or it will add, modify, or delete ACL entries.
For more information on Cygwin and Windows ACLs, see
see in the Cygwin User's Guide.
Acl_entries are one or more comma-separated ACL entries
from the following list:
u[ser]::perm
u[ser]:uid:perm
g[roup]::perm
g[roup]:gid:perm
m[ask]::perm
o[ther]::perm
Default entries are like the above with the additional
default identifier. For example:
d[efault]:u[ser]:uid:perm
perm is either a 3-char permissions string in the form
"rwx" with the character '-' for no permission
or it is the octal representation of the permissions, a
value from 0 (equivalent to "---") to 7 ("rwx").
uid is a user name or a numerical uid.
gid is a group name or a numerical gid.
The following options are supported:
-d
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:
u[ser]:uid
g[roup]:gid
d[efault]:u[ser]:uid
d[efault]:g[roup]:gid
d[efault]:m[ask]:
d[efault]:o[ther]:
-f
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
getfacl and setfacl to copy
ACLs from one file to another:
$ getfacl source_file | setfacl -f - target_file
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.
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.
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.
-m
Add or modify one or more specified ACL entries. Acl_entries is a
comma-separated list of entries from the same list as above.
-r
Causes the permissions specified in the mask
entry to be ignored and replaced by the maximum permissions needed for
the file group class.
-s
Like -f, but substitute the
file's ACL with Acl_entries specified in a comma-separated list on the
command line.
While the -d and -m options may be used
in the same command, the -f and -s
options may be used only exclusively.
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
Limitations: Under Cygwin, the default ACL entries are not taken into
account currently.
ssp
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
SSP - The Single Step Profiler
Original Author: DJ Delorie
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 gprof, although
gprof will claim the values
are seconds, they really are instruction counts. More on that later.
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 gprof won't run)
and run objdump like this:
$ objdump -h cygwin1.dll
It will print a report like this:
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
. . .
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).
There are two basic ways to use SSP - either profiling a whole
program, or selectively profiling parts of the program.
To profile a whole program, just run ssp without options.
By default, it will step the whole program. Here's a simple example, using
the numbers above:
$ ssp 0x61001000 0x61080000 hello.exe
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
gprof:
$ gprof -b cygwin1.dll
The "-b" means 'skip the help pages'. You can omit this until you're
familiar with the report layout. The gprof documentation
explains a lot about this report, but ssp changes a few
things. For example, the first part of the report reports the amount of time
spent in each function, like this:
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
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.
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:
#include <windows.h>
main()
{
time_t t;
OutputDebugString("ssp on");
time(&t);
OutputDebugString("ssp off");
}
Then, add the -d 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 gprof (as usual) to see the performance
profile for just that portion of the program's execution.
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.
-v - verbose. This prints messages about threads
starting and stopping, OutputDebugString calls, DLLs loading, etc.
-t and -c - tracing.
With -t, *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. -c prints each address to
the console, useful for debugging key chunks of assembler. Use
addr2line -C -f -s -e foo.exe < trace.ssp > lines.ssp
and then perl cvttrace to convert to symbolic traces.
-s - 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.
-l - 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 -v, -s, and
-l options:
$ ssp -v -s -l -d 0x61001000 0x61080000 hello.exe
strace
Usage: strace.exe [OPTIONS] <command-line>
Usage: strace.exe [OPTIONS] -p <pid>
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 <pid>
-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.
The strace 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 -o
option. With the -w option, you can start an strace
session in a new window, for example:
$ strace -o tracing_output -w sh -c 'while true; do echo "tracing..."; done' &
This is particularly useful for strace sessions that
take a long time to complete.
Note that strace is a standalone Windows program and so does
not rely on the Cygwin DLL itself (you can verify this with
cygcheck). As a result it does not understand symlinks.
This program is mainly useful for debugging the Cygwin DLL itself.
umount
Usage: umount.exe [OPTION] [<posixpath>]
Unmount filesystems
-h, --help output usage information and exit
-U, --remove-user-mounts remove all user mounts
-v, --version output version information and exit
The umount program removes mounts from the
mount table in the current session. If you specify a POSIX path that
corresponds to a current mount point, umount will
remove it from the current mount table. Note that you can only remove
user mount points. The -U flag may be used to
specify removing all user mount points from the current user session.
See for more information on the mount
table.