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. chattr 1 Cygwin Utilities chattr Change file attributes chattr -RVf + - = MODE FILE chattr -H -v -R, --recursive recursively apply the changes to directories and their contents -V, --verbose Be verbose during operation -f, --force suppress error messages -H, --help this help text -v, --version display the program version The chattr program allows to change file attributes, namely DOS attributes, as well as making files sparse, encrypt or compress them on FS level, or setting directories' case sensitivity. The format of 'mode' is {+-=}[acCehnrsSt] The operator '+' causes the selected attributes to be added to the existing attributes of the files; '-' causes them to be removed; and '=' causes them to be the only attributes that the files have. A single '=' causes all attributes to be removed. Supported attributes: 'r', 'Readonly': file is read-only 'h', 'Hidden': file or directory is hidden 's', 'System': file or directory that the operating system uses 'a', 'Archive': file or directory has the archive marker set 't', 'Temporary': file is being used for temporary storage 'S', 'Sparse': file is sparse 'c', 'Compressed': file or directory is compressed 'n', 'Notindexed': file or directory is not to be indexed by the content indexing service 'e', 'Encrypted': file is encrypted 'C', 'Casesensitive': directory is handled case sensitive (Windows 10 1803 or later, local NTFS only, WSL must be installed) cygcheck 1 Cygwin Utilities cygcheck List system information, check installed packages, or query package database cygcheck -v -h PROGRAM cygcheck -c -d PACKAGE cygcheck -s -r -v -h cygcheck -k cygcheck -f FILE cygcheck -l PACKAGE cygcheck -p REGEXP cygcheck --delete-orphaned-installation-keys cygcheck -h -V 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. -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: $ 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 relevant 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 equivalent 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: $ 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. cygpath 1 Cygwin Utilities cygpath Convert Unix and Windows format paths, or output system path information cygpath -d -m -u -w -t TYPE -f FILE -i CONVERSION_OPTION NAME cygpath -c HANDLE cygpath -A -D -H -O -P -S -W -F ID cygpath -h -V 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') -U, --proc-cygdrive Emit /proc/cygdrive path instead of cygdrive prefix when converting Windows path to UNIX path. -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 sufficient 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 -U option allows to use cygpath to create unambiguous Unix paths pointing outside the Cygwin tree andf thus having no explicit POSIX path. Those paths usually use the cygdrive prefix. However, the cygdrive prefix can be changed by the user, so symbolic links created using the cygdrive prefix are not foolproof. With -U cygpath will generate such paths prepended by the virtual /proc/cygdrive symbolic link, which will never change, so the created path is safe against changing the cygdrive prefix. 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. 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 0x-prefixed hex). 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 1 Cygwin Utilities dumper Dump core from WIN32PID to FILENAME.core dumper -n -d -q FILENAME WIN32PID dumper -h -V -n, --nokill don't terminate the dumped process -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. For historical reasons, unless the -n option is given, after the core dump is created and when the dumper exits, the target process is also terminated. To save space in the core dump, dumper doesn't write those portions of the target process's memory space that are loaded from executable and dll files and are unchanged (e.g. program code). Instead, dumper saves paths to the files which contain that data. When a core dump is loaded into gdb, it uses these paths to load the 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. getconf 1 Cygwin Utilities getconf Get configuration values getconf -v specification variable_name pathname getconf -a pathname getconf -h -V -v specification Indicate specific version for which configuration values shall be fetched. -a, --all Print all known configuration values Other options: -h, --help This text -V, --version Print program version and exit The getconf utility prints the value of the configuration variable specified by variable_name. If no pathname is given, getconf serves as a wrapper for the confstr and sysconf functions, supporting the symbolic constants defined in the limits.h and unistd.h headers, without their respective _CS_ or _SC_ prefixes. If pathname is given, getconf prints the value of the configuration variable for the specified pathname. In this form, getconf serves as a wrapper for the pathconf function, supporting the symbolic constants defined in the unistd.h header, without the _PC_ prefix. If you specify the -v option, the parameter denotes a specification for which the value of the configuration variable should be printed. Note that the only specifications supported by Cygwin are POSIX_V7_ILP32_OFFBIG and the legacy POSIX_V6_ILP32_OFFBIG and XBS5_ILP32_OFFBIG equivalents. Use the -a option to print a list of all available configuration variables for the system, or given pathname, and their values. getfacl 1 Cygwin Utilities getfacl Display file and directory access control lists (ACLs) getfacl -adceEn FILE getfacl -h -V -a, --access display the file access control list only -d, --default display the default access control list only -c, --omit-header do not display the comment header -e, --all-effective print all effective rights -E, --no-effective print no effective rights -n, --numeric print numeric user/group identifiers -V, --version print version and exit -h, --help this help text 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, the setuid (s), setgid (s), and sticky (t) bits if available, 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 # flags: sst 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 gmondump 1 Cygwin Utilities gmondump Display formatted contents of profile data files gmondump -v FILENAME gmondump -h -V -h, --help Display usage information and exit -v, --verbose Display more file details (toggle: default false) -V, --version Display version information and exit The gmondump utility displays the contents of one or more profile data files. Such files usually have names starting with "gmon.out" and are created by a profiling program such as profiler or ssp. Compiling your gcc/g++ programs with option -pg also works. By default, summary information is shown. You can use the option -v to get more detailed displays. Note that gmondump just displays the raw data; one would usually use gprof to display the data in a useful form incorporating symbolic info such as function names and source line numbers. Here is an example of gmondump operation: $ gmondump gmon.out.21900.zstd.exe file gmon.out.21900.zstd.exe, gmon version 0x51879, sample rate 100 address range 0x100401000..0x1004cc668 numbuckets 208282, hitbuckets 1199, hitcount 12124, numrawarcs 0 kill 1 Cygwin Utilities kill Send signals to processes kill -f -signal -s signal pid kill -l signal kill -h -V -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) -W, --winpid specified pids are windows PIDs, not Cygwin PIDs (use with extreme caution!) -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. The -f option uses Windows functions to terminate processes forcefully. Use -f to terminate native Windows processes not started by Cygwin processes. -f can also be useful to terminate Cygwin processes not answering to SIGKILL. Unless you specific the -W 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: $ 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 SIGIOT 6 another name for SIGABRT SIGEMT 7 EMT instruction SIGFPE 8 floating point exception SIGKILL 9 kill (cannot be caught or ignored) SIGBUS 10 bus error SIGSEGV 11 segmentation violation SIGSYS 12 bad argument to system call SIGPIPE 13 write on a pipe with no one to read it SIGALRM 14 alarm clock SIGTERM 15 software termination signal from kill SIGURG 16 urgent condition on IO channel SIGSTOP 17 sendable stop signal not from tty SIGTSTP 18 stop signal from tty SIGCONT 19 continue a stopped process SIGCHLD 20 to parent on child stop or exit SIGCLD 20 System V name for SIGCHLD SIGTTIN 21 to readers pgrp upon background tty read SIGTTOU 22 like TTIN for output if (tp->t_local&LTOSTOP) SIGIO 23 input/output possible SIGPOLL 23 System V name for SIGIO SIGXCPU 24 exceeded CPU time limit SIGXFSZ 25 exceeded file size limit SIGVTALRM 26 virtual time alarm SIGPROF 27 profiling time alarm SIGWINCH 28 window changed SIGLOST 29 resource lost (eg, record-lock lost) SIGPWR 29 power failure SIGUSR1 30 user defined signal 1 SIGUSR2 31 user defined signal 2 ldd 1 Cygwin Utilities ldd Print shared library dependencies ldd -ruv FILE ldd -h -V -h, --help print this help and exit -V, --version print version information and exit -r, --function-relocs process data and function relocations (currently unimplemented) -u, --unused print unused direct dependencies (currently unimplemented) -v, --verbose print all information (currently unimplemented) ldd prints the shared libraries (DLLs) loaded when running an executable or DLL. ldd invokes the Windows loader on the file specified, then uses the Windows debugging interface to report DLLs loaded, and (for executables) to attempt to stop execution before the entrypoint. Thus, you should never use ldd on an untrusted file. locale 1 Cygwin Utilities locale Get locale-specific information locale -amvhV locale -ck NAME locale -iusfnU locale -h -V System information: -a, --all-locales List all available supported locales -m, --charmaps List all available character maps -v, --verbose More verbose output Modify output format: -c, --category-name List information about given category NAME -k, --keyword-name Print information about given keyword NAME Default locale information: -i, --input Print current input locale -u, --user Print locale of user's default UI language -s, --system Print locale of system default UI language -f, --format Print locale of user's regional format settings (time, numeric & monetary) -n, --no-unicode Print system default locale for non-Unicode programs -U, --utf Attach \".UTF-8\" to the result Other options: -h, --help This text -V, --version Print program version and exit locale without parameters prints information about the current locale environment settings. The -i, -u, -s, -f, and -n options can be used to request the various Windows locale settings. The purpose is to use this command in scripts to set the POSIX locale variables. The -i option prints the current input language. This is called the "Input language" and basically equivalent to the current keyboard layout setting. The -u option prints the current user's Windows UI locale to stdout. In Windows this setting is called the "Display Language". The -s option prints the systems default instead. The -f option prints the user's setting for time, date, number and currency. That's equivalent to the setting in the "Formats" or "Regional Options" tab in the "Region and Language" or "Regional and Language Options" dialog. The -n option prints the system's default language used for applications which don't support Unicode. With the -U option locale appends the string ".UTF-8" to enforce using UTF-8. Using UTF-8 as codeset is recommended. Usage example: bash$ export LANG=$(locale -uU) bash$ echo $LANG en_US.UTF-8 bash$ export LC_TIME=$(locale -fU) bash$ echo $LC_TIME de_DE.UTF-8 The -a option is helpful to learn which locales are supported by your Windows machine. It prints all available locales and the allowed modifiers. Example: bash$ locale -a C C.utf8 POSIX af_ZA af_ZA.utf8 am_ET am_ET.utf8 ... be_BY be_BY.utf8 be_BY@latin ... ca_ES ca_ES.utf8 ca_ES@euro catalan ... The -v option prints more detailed information about each available locale. Example: bash$ locale -av locale: af_ZA archive: /cygdrive/c/Windows/system32/kernel32.dll ------------------------------------------------------------------------------- language | Afrikaans territory | South Africa codeset | ISO-8859-1 locale: af_ZA.utf8 archive: /cygdrive/c/Windows/system32/kernel32.dll ------------------------------------------------------------------------------- language | Afrikaans territory | South Africa codeset | UTF-8 ... locale: ca_ES@euro archive: /cygdrive/c/Windows/system32/kernel32.dll ------------------------------------------------------------------------------- language | Catalan territory | Spain codeset | ISO-8859-15 locale: catalan archive: /usr/share/locale/locale.alias ------------------------------------------------------------------------------- language | Catalan territory | Spain codeset | ISO-8859-1 ... The -m option prints the names of the available charmaps supported by Cygwin to stdout. Otherwise, if arguments are given, locale prints the values assigned to these arguments. Arguments can be names of locale categories (for instance: LC_CTYPE, LC_MONETARY), or names of keywords supported in the locale categories (for instance: thousands_sep, charmap). The -c option prints additionally the name of the category. The -k option prints additionally the name of the keyword. Example: bash$ locale -ck LC_MESSAGES LC_MESSAGES yesexpr="^[yY]" noexpr="^[nN]" yesstr="yes" nostr="no" messages-codeset="UTF-8" bash$ locale noexpr ^[nN] lsattr 1 Cygwin Utilities lsattr List file attributes lsattr -Radln FILE lsattr -h -V -R, --recursive recursively list attributes of directories and their contents -V, --version display the program version -a, --all list all files in directories, including files that start with '.' -d, --directory list directories like other files, rather than listing their contents. -l, --long print options using long names instead of single character abbreviations -n, --no-headers don't print directory headers when recursing -h, --help this help text The lsattr program allows to list file attributes, namely DOS attributes, file sparseness, FS level encryption and compression state, as well as directories' case sensitivity setting. Supported attributes: 'r', 'Readonly': file is read-only, directory is system-marked 'h', 'Hidden': file or directory is hidden 's', 'System': file or directory that the operating system uses 'a', 'Archive': file or directory has the archive marker set 't', 'Temporary': file is being used for temporary storage 'S', 'Sparse': file is sparse 'r', 'Reparse': file or directory that has a reparse point 'c', 'Compressed': file or directory is compressed 'o', 'Offline': the data of a file is moved to offline storage 'n', 'Notindexed': file or directory is not to be indexed by the content indexing service 'e', 'Encrypted': file is encrypted 'C', 'Casesensitive': directory is handled case sensitive (Windows 10 1803 or later, local NTFS only, WSL must be installed) minidumper 1 Cygwin Utilities minidumper Write minidump from WIN32PID to FILENAME.dmp minidumper -d -n -q -t TYPE FILENAME WIN32PID minidumper -h -V -t, --type minidump type flags -n, --nokill don't terminate the dumped process -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 minidumper utility can be used to create a minidump of a running Windows process. This minidump can be later analysed using breakpad or Windows debugging tools. minidumper can be used with cygwin's Just-In-Time debugging facility in exactly the same way as dumper (See ). minidumper can also be started from the command line to create a minidump of any running process. For compatibility with dumper the target process is terminated after dumping unless the -n option is given. mkgroup 1 Cygwin Utilities mkgroup Write /etc/group-like output to stdout mkgroup -l -L MACHINE -d DOMAIN -c -S CHAR -o OFFSET -g GROUPNAME -b -U GROUPLIST mkgroup -h -V -l,--local [machine] Print local group accounts of \"machine\", from local machine if no machine specified. Automatically adding machine prefix for local machine depends on settings in /etc/nsswitch.conf. -L,--Local [machine] Ditto, but generate groupname with machine prefix. -d,--domain [domain] Print domain groups, from current domain if no domain specified. -c,--current Print current group. -S,--separator char For -L use character char as domain\\group separator in groupname instead of default '+'. -o,--id-offset offset Change the default offset (0x10000) added to gids -g,--group groupname Only return information for the specified group. One of -l, -d must be specified, too. -b,--no-builtin Don't print BUILTIN groups. -U,--unix grouplist Print UNIX groups when using -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! -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. Don't use this command to generate a local /etc/group file, unless you really need one. See the Cygwin User's Guide for more information. The mkgroup program can be used to create a local /etc/group file. Cygwin doesn't need this file, because it reads group information from the Windows account databases, but you can add an /etc/group file for instance, if your machine is often disconnected from its domain controller. Note that this information is static, in contrast to the information automatically gathered by Cygwin from the Windows account databases. If you change the group information on your system, you'll need to regenerate the group file for it to have the new information. By default, the information generated by mkgroup is equivalent to the information generated by Cygwin itself. The -d and -l/-L options allow you to specify where the information comes from, some domain, or the local SAM of a machine. Note that you can only enumerate accounts from trusted domains. Any non-trusted domain will be ignored. Access-restrictions of your current account apply. The -l/-L when used with a machine name, tries to contact that machine to enumerate local groups of other machines, typically outside of domains. This scenario cannot be covered by Cygwin's account automatism. If you want to use the -L option, but you don't like the default domain/group separator from /etc/nsswitch.conf, you can specify another separator using the -S option, for instance: $ mkgroup -L server1 -S= > /etc/group For very simple needs, an entry for the current user's group can be created by using the option -c. The -o option allows for (unlikely) special cases with multiple machines 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 1 Cygwin Utilities mkpasswd Write /etc/passwd-like output to stdout mkpasswd -l -L MACHINE -d DOMAIN -c -S CHAR -o OFFSET -u USERNAME -b -U USERLIST mkpassword -h -V -l,--local [machine] Print local user accounts of \"machine\", from local machine if no machine specified. Automatically adding machine prefix for local machine depends on settings in /etc/nsswitch.conf. -L,--Local [machine] Ditto, but generate username with machine prefix. -d,--domain [domain] Print domain accounts, from current domain if no domain specified. -c,--current Print current user. -S,--separator char For -L use character char as domain\\user separator in username instead of the default '+'. -o,--id-offset offset Change the default offset (0x10000) added to uids of foreign local machine accounts. Use with -l/-L. -u,--username username Only return information for the specified user. One of -l, -d must be specified, too -b,--no-builtin Don't print BUILTIN users. -p,--path-to-home path Use specified path instead of user account home dir or /home prefix. -U,--unix userlist Print UNIX users when using -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! -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. Don't use this command to generate a local /etc/passwd file, unless you really need one. See the Cygwin User's Guide for more information. The mkpasswd program can be used to create a /etc/passwd file. Cygwin doesn't need this file, because it reads user information from the Windows account databases, but you can add an /etc/passwd file, for instance if your machine is often disconnected from its domain controller. Note that this information is static, in contrast to the information automatically gathered by Cygwin from the Windows account databases. If you change the user information on your system, you'll need to regenerate the passwd file for it to have the new information. By default, the information generated by mkpasswd is equivalent to the information generated by Cygwin itself. The -d and -l/-L options allow you to specify where the information comes from, some domain, or the local SAM of a machine. Note that you can only enumerate accounts from trusted domains. Any non-trusted domain will be ignored. Access-restrictions of your current account apply. The -l/-L when used with a machine name, tries to contact that machine to enumerate local groups of other machines, typically outside of domains. This scenario cannot be covered by Cygwin's account automatism. If you want to use the -L option, but you don't like the default domain/group separator from /etc/nsswitch.conf, you can specify another separator using the -S option, analog to mkgroup. For very simple needs, an entry for the current user can be created by using the option -c. The -o option allows for special cases (such as multiple domains) where the UIDs might match otherwise. The -p option causes mkpasswd to use the specified prefix instead of the account home dir or /home/ . For example, this command: $ 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 1 Cygwin Utilities mount Display information about mounted filesystems, or mount a filesystem mount -f -o MOUNT_OPTION, WIN32PATH POSIXPATH mount -a mount POSIXPATH mount -m mount -c POSIXPATH -p mount -h -V -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 If you just type mount with no parameters, it will display the current mount table for you. $ 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 /mnt/c type ntfs (binary,user,noumount) D: on /mnt/d type fat (binary,user,noumount) In this example, c:/cygwin is the POSIX root and the D drive is mapped to /mnt/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 /mnt/d mount is only visible to the current user. The mount utility is also the mechanism for adding new mounts to the mount table in memory. The following example demonstrates how to mount the directory //pollux/home/joe/data to /data for the duration of the current session. $ 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). bind - Allows to remount part of the file hierarchy somewhere else. Different from other mount calls, the first argument specifies an absolute POSIX path, rather than a Win32 path. This POSIX path is remounted to the POSIX path specified as the second parameter. The conversion to a Win32 path is done within Cygwin immediately at the time of the call. Note that symlinks are ignored while performing this path conversion. cygexec - Treat all files below mount point as cygwin executables. dos - Always convert leading spaces and trailing dots and spaces to characters in the UNICODE private use area. This allows to use broken filesystems which only allow DOS filenames, even if they are not recognized as such by Cygwin. exec - Treat all files below mount point as executable. ihash - Always fake inode numbers rather than using the ones returned by the filesystem. This allows to use broken filesystems which don't return unambiguous inode numbers, even if they are not recognized as such by Cygwin. noacl - Ignore ACLs and fake POSIX permissions. nosuid - No suid files are allowed (currently unimplemented) notexec - Treat all files below mount point as not executable. override - Override immutable mount points. posix=0 - Switch off case sensitivity for paths under this mount point. posix=1 - Switch on case sensitivity for paths under this mount point (default). sparse - Switch on support for sparse files. This option only makes sense on NTFS and then only if you really need sparse files. 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. To bind a POSIX path to another POSIX path, use the bind mount flag. $ mount -o bind /var /usr/var This command makes the file hirarchy under /var additionally available under /usr/var. 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. 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: $ 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) $ mount -c /mnt -o binary,noacl Limitations: there is a hard-coded limit of 64 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 1 Cygwin Utilities passwd Change password or password attributes passwd -S -l -u -c -C -e -E -p -P -d SERVER USER passwd -R passwd -i NUM -n MINDAYS -x MAXDAYS -L LEN passwd -h -V 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 MINDAYS set system minimum password age to MINDAYS days. -x, --maxage MAXDAYS set system maximum password age to MAXDAYS days. -L, --length LEN set system minimum password length to LEN. Other options: -d, --logonserver SERVER connect to SERVER (e.g. domain controller). Usually not required. -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 logon server is evaluated automatically. In rare cases, it might be necessary to switch to another domain controller to perform the action. In this case, use the -d option to specify the machine to run the command against. Note that the current user must have account operator permissions to perform user account changes in a domain. 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. Administrators can enter the password for other user accounts into the registry by specifying the username on the commandline. 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. pldd 1 Cygwin Utilities pldd List dynamic shared objects loaded into a process pldd PID pldd -? --usage -V -?, --help Give this help list --usage Give a short usage message -V, --version Print program version pldd prints the shared libraries (DLLs) loaded by the process with the given PID. profiler 1 Cygwin Utilities profiler Sampling profiler of Cygwin programs with their DLLs profiler -defw -o FILENAME -s N PROGRAM ARG -p PID profiler -h -V -d, --debug Display debugging messages (toggle: default false) -e, --events Display Windows DEBUG_EVENTS (toggle: default false) -f, --fork-profile Profiles child processes (toggle: default false) -h, --help Display usage information and exit -o, --output=FILENAME Write output to file FILENAME rather than stdout -p, --pid=N Attach to running program with Cygwin pid N ... or with Windows pid -N -s, --sample-rate=N Set IP sampling rate to N Hz (default 100) -v, --verbose Display more status messages (toggle: default false) -V, --version Display version information and exit -w, --new-window Launch given command in a new window The profiler utility executes a given program and any children of that program, collecting the location of the CPU instruction pointer (IP) many times per second. (It is optional to collect this info from child processes.) This info gives a profile of the program's execution, showing where the most time is being spent. This profiling technique is called "IP sampling". A novel feature of profiler is that time spent in DLLs loaded with or by your program is profiled too. You use gprof to process and display the resulting profile information. In this fashion you can determine whether your own code, the Cygwin DLL, or another DLL has "hot spots" that might benefit from tuning. (See also ssp, another profiler that operates in a different fashion: stepping by instruction. This can provide a different view on your program's operation.) Here is an example of profiler operation: $ profiler du -khs . 22G . 97 samples across 83 buckets written to gmon.out.5908.cygwin1.dll 4 samples across 4 buckets written to gmon.out.5908.KernelBase.dll 1 sample across 1 bucket written to gmon.out.5908.kernel32.dll 7318 samples across 42 buckets written to gmon.out.5908.ntdll.dll 5 samples across 4 buckets written to gmon.out.5908.du.exe ps 1 Cygwin Utilities ps Report process status ps -aeflsW -u UID -p PID ps -h -V -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 1 Cygwin Utilities regtool View or edit the Windows registry regtool -qvwW add|check|get|list|remove|unset|load|unload|save KEY PATH DATA regtool add KEY\SUBKEY regtool check KEY regtool -bnx get KEY regtool -klp list KEY regtool remove KEY regtool -bDeimnQsf set KEY\VALUE DATA regtool -f unset KEY\VALUE regtool load KEY\SUBKEY PATH regtool unload KEY\SUBKEY regtool save KEY\SUBKEY PATH regtool -f restore KEY/SUBKEY PATH regtool -h -V 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 file PATH restore KEY\SUBKEY PATH restore SUBKEY from file 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 '\' Options for 'restore' action: -f, --force restore even if open handles exist at or beneath the location in the registry hierarchy to which KEY\SUBKEY points 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 an escape character. You can also supply the registry path prefix /proc/registry{,32,64}/ to use path completion. Example: regtool list '/HKLM/SOFTWARE/Classes/MIME/Database/Content Type/audio\\/wav' 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 file. Ideally you append the suffix .reg to the file so it gets automatically recognized as registry file by Windows Explorer. The restore action restores a registry subkey from a file saved via the aforementioned save action. 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 1 Cygwin Utilities setfacl Modify file and directory access control lists (ACLs) setfacl -n -f ACL_FILE -s acl_entries FILE setfacl -n -bk -x acl_entries -m acl_entries FILE setfacl -h -V -b, --remove-all remove all extended ACL entries -x, --delete delete one or more specified ACL entries -f, --set-file set ACL entries for FILE to ACL entries read from ACL_FILE -k, --remove-default remove all default ACL entries -m, --modify modify one or more specified ACL entries -n, --no-mask don't recalculate the effective rights mask --mask do recalculate the effective rights mask -s, --set set specified ACL entries on FILE -V, --version print version and exit -h, --help this help text At least one of (-b, -x, -f, -k, -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 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: -b,--remove-all Remove all extended ACL entries. The base ACL entries of the owner, group and others are retained. This option can be combined with the -k,--remove-default option to delete all non-standard POSIX permissions. -x,--delete 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[:] m[ask][:] d[efault]:u[ser][:uid] d[efault]:g[roup][:gid] d[efault]:m[ask][:] d[efault]:o[ther][:] -f,--set-file 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. -k,--remove-default Remove all default ACL entries. If no default ACL entries exist, no warnings are issued. This option can be combined with the -b,--remove-all option to delete all non-standard POSIX permissions. -m,--modify Add or modify one or more specified ACL entries. Acl_entries is a comma-separated list of entries from the same list as above. -n,--no-mask Valid in conjunction with -m. Do not recalculate the effective rights mask. The default behavior of setfacl is to recalculate the ACL mask entry, unless a mask entry was explicitly given. The mask entry is set to the union of all permissions of the owning group, and all named user and group entries. (These are exactly the entries affected by the mask entry). --mask Valid in conjunction with -m. Do recalculate the effective rights mask, even if an ACL mask entry was explicitly given. (See the -n option.) -s,--set Like -f, but set the file's ACL with Acl_entries specified in a comma-separated list on the command line. While the -x 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. setmetamode 1 Cygwin Utilities setmetamode Get or set keyboard meta mode setmetamode metabit escprefix setmetamode -h -V Without argument, it shows the current meta key mode. metabit|meta|bit The meta key sets the top bit of the character. escprefix|esc|prefix The meta key sends an escape prefix. Other options: -h, --help This text -V, --version Print program version and exit setmetamode can be used to determine and set the key code sent by the meta (aka Alt) key. ssp 1 Cygwin Utilities DJ Delorie Original Author ssp The Single Step Profiler ssp -cdelstv low_pc high_pc command ssp -h -V -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 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. (See also profiler, another profiler that operates in a different fashion: IP sampling. This can provide a different view on your program's operation.) 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 0x6107fa00 (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 1 Cygwin Utilities strace Trace system calls and signals strace -defnqtuw -b SIZE -m MASK -o FILENAME -f PERIOD command-line -T -p pid strace -h -V -b, --buffer-size=SIZE set size of output file buffer -d, --no-delta don't display the delta-t microsecond timestamp -e, --events log all Windows DEBUG_EVENTS (toggle - default true) -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 traced. Requires -p <pid> -u, --usecs toggle printing of microseconds timestamp -V, --version output version information and exit -w, --new-window spawn program under test in a new window MASK can be any combination of the following mnemonics and/or hex values (0x is optional). Combine masks with '+' or ',' like so: --mask=wm+system,malloc+0x00800 Mnemonic Hex Corresponding Def Description ========================================================================= all 0x000001 (_STRACE_ALL) All strace messages. flush 0x000002 (_STRACE_FLUSH) Flush output buffer after each message. inherit 0x000004 (_STRACE_INHERIT) Children inherit mask from parent. uhoh 0x000008 (_STRACE_UHOH) Unusual or weird phenomenon. syscall 0x000010 (_STRACE_SYSCALL) System calls. startup 0x000020 (_STRACE_STARTUP) argc/envp printout at startup. debug 0x000040 (_STRACE_DEBUG) Info to help debugging. paranoid 0x000080 (_STRACE_PARANOID) Paranoid info. termios 0x000100 (_STRACE_TERMIOS) Info for debugging termios stuff. select 0x000200 (_STRACE_SELECT) Info on ugly select internals. wm 0x000400 (_STRACE_WM) Trace Windows msgs (enable _strace_wm). sigp 0x000800 (_STRACE_SIGP) Trace signal and process handling. minimal 0x001000 (_STRACE_MINIMAL) Very minimal strace output. pthread 0x002000 (_STRACE_PTHREAD) Pthread calls. exitdump 0x004000 (_STRACE_EXITDUMP) Dump strace cache on exit. system 0x008000 (_STRACE_SYSTEM) Serious error; goes to console and log. nomutex 0x010000 (_STRACE_NOMUTEX) Don't use mutex for synchronization. malloc 0x020000 (_STRACE_MALLOC) Trace malloc calls. thread 0x040000 (_STRACE_THREAD) Thread-locking calls. special 0x100000 (_STRACE_SPECIAL) Special debugging printfs for non-checked-in code 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. tzset 1 Cygwin Utilities tzset Print POSIX-compatible timezone ID from current Windows timezone setting tzset -h -V Options: -h, --help output usage information and exit. -V, --version output version information and exit. Use tzset to set your TZ variable. In POSIX-compatible shells like bash, dash, mksh, or zsh: export TZ=$(tzset) In csh-compatible shells like tcsh: setenv TZ `tzset` The tzset tool reads the current timezone from Windows and generates a POSIX-compatible timezone information for the TZ environment variable from that information. That's all there is to it. For the way how to use it, see the above usage information. umount 1 Cygwin Utilities umount Unmount filesystems umount POSIXPATH umount -U umount -h -V -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.