<sect1 id="using-utils"><title>Cygwin Utilities</title> <para>Cygwin comes with a number of command-line utilities that are used to manage the UNIX emulation portion of the Cygwin environment. While many of these reflect their UNIX counterparts, each was written specifically for Cygwin. You may use the long or short option names interchangeably; for example, <literal>--help</literal> and <literal>-h</literal> function identically. All of the Cygwin command-line utilities support the <literal>--help</literal> and <literal>--version</literal> options. </para> <sect2 id="cygcheck"><title>cygcheck</title> <screen> Usage: cygcheck [OPTIONS] [program ...] -c, --check-setup check packages installed via setup.exe -s, --sysinfo system information (not with -k) -v, --verbose verbose output (indented) (for -s or programs) -r, --registry registry search (requires -s) -k, --keycheck perform a keyboard check session (not with -s) -h, --help give help about the info (not with -c) -V, --version output version information and exit You must at least give either -s or -k or a program name </screen> <para>The <command>cygcheck</command> program is a diagnostic utility that examines your system and reports the information that is significant to the proper operation of Cygwin programs. It can give information about specific programs or libraries you are trying to run, general system information, or both. If you list one or more programs on the command line, it will diagnose the runtime environment of that program or programs, providing the names of DLL files on which the program depends. If you specify the <literal>-s</literal> option, it will give general system information. If you specify <literal>-s</literal> and list one or more programs on the command line, it reports on both.</para> <para>The <literal>-h</literal> option prints additional helpful messages in the report, at the beginning of each section. It also adds table column headings. While this is useful information, it also adds some to the size of the report, so if you want a compact report or if you know what everything is already, just leave this out.</para> <para>The <literal>-v</literal> option causes the output to be more verbose. What this means is that additional information will be reported which is usually not interesting, such as the internal version numbers of DLLs, additional information about recursive DLL usage, and if a file in one directory in the PATH also occurs in other directories on the PATH. </para> <para>The <literal>-r</literal> option causes <command>cygcheck</command> to search your registry for information that is relevent to Cygwin programs. These registry entries are the ones that have "Cygwin" in the name. If you are paranoid about privacy, you may remove information from this report, but please keep in mind that doing so makes it harder to diagnose your problems.</para> <para>The <literal>-c</literal> option causes the arguments to be interpreted as package names. <command>cygcheck</command> will report the current version of the package that you specify, or with no arguments, on all packages.</para> <para>The <command>cygcheck</command> program should be used to send information about your system for troubleshooting when requested. When asked to run this command save the output so that you can email it, for example:</para> <screen> <prompt>C:\cygwin></prompt> <userinput>cygcheck -s -v -r -h > cygcheck_output.txt</userinput> </screen> </sect2> <sect2 id="cygpath"><title>cygpath</title> <screen> Usage: cygpath (-d|-m|-u|-w|-t TYPE) [-c HANDLE] [-f FILE] [options] NAME cygpath [-ADHPSW] Output type options: -d, --dos print DOS (short) form of NAME (C:\PROGRA~1\) -m, --mixed like --windows, but with regular slashes (C:/WINNT) -u, --unix (default) print Unix form of NAME (/cygdrive/c/winnt) -w, --windows print Windows form of NAME (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 NAME (with -w, -m only) -p, --path NAME is a PATH list (i.e., '/bin:/usr/bin') -s, --short-name print DOS (short) form of NAME (with -w, -m only) System information: -A, --allusers use `All Users' instead of current user for -D, -P -D, --desktop output `Desktop' directory and exit -H, --homeroot output `Profiles' directory (home root) and exit -P, --smprograms output Start Menu `Programs' directory and exit -S, --sysdir output system directory and exit -W, --windir output `Windows' directory and exit </screen> <para>The <command>cygpath</command> program is a utility that converts Windows native filenames to Cygwin POSIX-style pathnames and vice versa. It can be used when a Cygwin program needs to pass a file name to a native Windows program, or expects to get a file name from a native Windows program. Alternatively, <command>cygpath</command> can output information about the location of important system directories in either format. </para> <para>The <literal>-u</literal> and <literal>-w</literal> options indicate whether you want a conversion to UNIX (POSIX) format (<literal>-u</literal>) or to Windows format (<literal>-w</literal>). Use the <literal>-d</literal> to get DOS-style (8.3) file and path names. The <literal>-m</literal> option will output Windows-style format but with forward slashes instead of backslashes. This option is especially useful in shell scripts, which use backslashes as an escape character.</para> <para> In combination with the <literal>-w</literal> option, you can use the <literal>-l</literal> and <literal>-s</literal> options to use normal (long) or DOS-style (short) form. The <literal>-d</literal> option is identical to <literal>-w</literal> and <literal>-s</literal> together. </para> <para>Caveat: The <literal>-l</literal> option does not work if the <emphasis>check_case</emphasis> parameter of <emphasis>CYGWIN</emphasis> is set to <emphasis>strict</emphasis>, since Cygwin is not able to match any Windows short path in this mode. </para> <para>The <literal>-p</literal> option means that you want to convert a path-style string rather than a single filename. For example, the PATH environment variable is semicolon-delimited in Windows, but colon-delimited in UNIX. By giving <literal>-p</literal> you are instructing <command>cygpath</command> to convert between these formats.</para> <para>The <literal>-i</literal> option supresses the print out of the usage message if no filename argument was given. It can be used in make file rules converting variables that may be omitted to a proper format. Note that <command>cygpath</command> output may contain spaces (C:\Program Files) so should be enclosed in quotes. </para> <example><title>Example cygpath usage</title> <screen> #!/bin/sh if [ "${1}" = "" ]; then XPATH="."; else XPATH="$(cygpath -w "${1}")"; fi explorer $XPATH & </screen> </example> <para>The capital options <literal>-D</literal>, <literal>-H</literal>, <literal>-P</literal>, <literal>-S</literal>, and <literal>-W</literal> output directories used by Windows that are not the same on all systems, for example <literal>-S</literal> might output C:\WINNT\SYSTEM32 or C:\WINDOWS\SYSTEM. The <literal>-H</literal> shows the Windows profiles directory that can be used as root of home. The <literal>-A</literal> option forces use of the "All Users" directories instead of the current user for the <literal>-D</literal> and <literal>-P</literal> options. On Win9x systems with only a single user, <literal>-A</literal> has no effect; <literal>-D</literal> and <literal>-AD</literal> would have the same output. By default the output is in UNIX (POSIX) format; use the <literal>-w</literal> or <literal>-d</literal> options to get other formats.</para> </sect2> <sect2 id="dumper"><title>dumper</title> <screen> Usage: dumper [OPTION] FILENAME WIN32PID Dump core from WIN32PID to FILENAME.core -d, --verbose be verbose while dumping -h, --help output help information and exit -q, --quiet be quiet while dumping (default) -v, --version output version information and exit </screen> <para>The <command>dumper</command> utility can be used to create a core dump of running Windows process. This core dump can be later loaded to <command>gdb</command> and analyzed. One common way to use <command>dumper</command> is to plug it into cygwin's Just-In-Time debugging facility by adding <screen> error_start=x:\path\to\dumper.exe </screen> to the <emphasis>CYGWIN</emphasis> environment variable. Please note that <literal>x:\path\to\dumper.exe</literal> is Windows-style and not cygwin path. If <literal>error_start</literal> is set this way, then dumper will be started whenever some program encounters a fatal error. </para> <para> <command>dumper</command> can be also be started from the command line to create a core dump of any running process. Unfortunately, because of a Windows API limitation, when a core dump is created and <command>dumper</command> exits, the target process is terminated too. </para> <para> To save space in the core dump, <command>dumper</command> doesn't write those portions of target process' memory space that are loaded from executable and dll files and are unchangeable, such as program code and debug info. Instead, <command>dumper</command> saves paths to files which contain that data. When a core dump is loaded into gdb, it uses these paths to load appropriate files. That means that if you create a core dump on one machine and try to debug it on another, you'll need to place identical copies of the executable and dlls in the same directories as on the machine where the core dump was created. </para> </sect2> <sect2 id="getfacl"><title>getfacl</title> <screen> Usage: getfacl [-adn] FILE [FILE2...] Display file and directory access control lists (ACLs). -a, --all display the filename, the owner, the group, and the ACL of the file -d, --dir display the filename, the owner, the group, and the default ACL of the directory, if it exists -h, --help output usage information and exit -n, --noname display user and group IDs instead of names -v, --version output version information and exit When multiple files are specified on the command line, a blank line separates the ACLs for each file. </screen> <para> For each argument that is a regular file, special file or directory, <command>getfacl</command> displays the owner, the group, and the ACL. For directories <command>getfacl</command> displays additionally the default ACL. With no options specified, <command>getfacl</command> displays the filename, the owner, the group, and both the ACL and the default ACL, if it exists. For more information on Cygwin and Windows ACLs, see see <Xref Linkend="ntsec"> in the Cygwin User's Guide. The format for ACL output is as follows: <screen> # file: filename # owner: name or uid # group: name or uid user::perm user:name or uid:perm group::perm group:name or gid:perm mask:perm other:perm default:user::perm default:user:name or uid:perm default:group::perm default:group:name or gid:perm default:mask:perm default:other:perm </screen> </para> </sect2> <sect2 id="kill"><title>kill</title> <screen> Usage: kill [-f] [-signal] [-s signal] pid1 [pid2 ...] kill -l [signal] -f, --force force, using win32 interface if necessary -l, --list print a list of signal names -s, --signal send signal (use kill --list for a list) -h, --help output usage information and exit -v, --version output version information and exit </screen> <para>The <command>kill</command> program allows you to send arbitrary signals to other Cygwin programs. The usual purpose is to end a running program from some other window when ^C won't work, but you can also send program-specified signals such as SIGUSR1 to trigger actions within the program, like enabling debugging or re-opening log files. Each program defines the signals they understand.</para> <para>You may need to specify the full path to use <command>kill</command> from within some shells, including <command>bash</command>, the default Cygwin shell. This is because <command>bash</command> defines a <command>kill</command> builtin function; see the <command>bash</command> man page under <emphasis>BUILTIN COMMANDS</emphasis> for more information. To make sure you are using the Cygwin version, try <screen> $ /bin/kill --version </screen> which should give the Cygwin <command>kill</command> version number and copyright information. </para> <para>Unless you specific the <literal>-f</literal> option, the "pid" values used by <command>kill</command> are the Cygwin pids, not the Windows pids. To get a list of running programs and their Cygwin pids, use the Cygwin <command>ps</command> program. <command>ps -W</command> will display <emphasis>all</emphasis> windows pids.</para> <para>The <command>kill -l</command> option prints the name of the given signal, or a list of all signal names if no signal is given.</para> <para>To send a specific signal, use the <literal>-signN</literal> option, either with a signal number or a signal name (minus the "SIG" part), like these examples:</para> <example><title>Using the kill command</title> <screen> <prompt>$</prompt> <userinput>kill 123</userinput> <prompt>$</prompt> <userinput>kill -1 123</userinput> <prompt>$</prompt> <userinput>kill -HUP 123</userinput> <prompt>$</prompt> <userinput>kill -f 123</userinput> </screen> </example> <para>Here is a list of available signals, their numbers, and some commentary on them, from the file <literal><sys/signal.h></literal>, which should be considered the official source of this information.</para> <screen> SIGHUP 1 hangup SIGINT 2 interrupt SIGQUIT 3 quit SIGILL 4 illegal instruction (not reset when caught) SIGTRAP 5 trace trap (not reset when caught) SIGABRT 6 used by abort SIGEMT 7 EMT instruction SIGFPE 8 floating point exception SIGKILL 9 kill (cannot be caught or ignored) SIGBUS 10 bus error SIGSEGV 11 segmentation violation SIGSYS 12 bad argument to system call SIGPIPE 13 write on a pipe with no one to read it SIGALRM 14 alarm clock SIGTERM 15 software termination signal from kill SIGURG 16 urgent condition on IO channel SIGSTOP 17 sendable stop signal not from tty SIGTSTP 18 stop signal from tty SIGCONT 19 continue a stopped process SIGCHLD 20 to parent on child stop or exit SIGTTIN 21 to readers pgrp upon background tty read SIGTTOU 22 like TTIN for output if (tp->t_local&LTOSTOP) SIGPOLL 23 System V name for SIGIO SIGXCPU 24 exceeded CPU time limit SIGXFSZ 25 exceeded file size limit SIGVTALRM 26 virtual time alarm SIGPROF 27 profiling time alarm SIGWINCH 28 window changed SIGLOST 29 resource lost (eg, record-lock lost) SIGUSR1 30 user defined signal 1 SIGUSR2 31 user defined signal 2 </screen> </sect2> <sect2 id="mkgroup"><title>mkgroup</title> <screen> Usage: mkgroup [OPTION]... [domain] This program prints a /etc/group file to stdout Options: -l,--local print local group information -d,--domain print global group information from the domain specified (or from the current domain if there is no domain specified) -o,--id-offset offset change the default offset (10000) added to uids in domain accounts. -s,--no-sids don't print SIDs in pwd field (this affects ntsec) -u,--users print user list in gr_mem field -h,--help print this message -v,--version print version information and exit One of `-l' or `-d' must be given on NT/W2K. </screen> <para>The <command>mkgroup</command> program can be used to help configure your Windows system to be more UNIX-like by creating an initial <filename>/etc/group</filename> substitute (some commands need this file) from your system information. It only works on the NT series (Windows NT, 2000, and XP). <command>mkgroup</command> does not work on the Win9x series (Windows 95, 98, and Me) because they lack the security model to support it. To initially set up your machine, you'd do something like this:</para> <example><title>Setting up the groups file</title> <screen> <prompt>$</prompt> <userinput>mkdir /etc</userinput> <prompt>$</prompt> <userinput>mkgroup -l > /etc/group</userinput> </screen> </example> <para>Note that this information is static. If you change the group information in your system, you'll need to regenerate the group file for it to have the new information.</para> <para>The <literal>-d</literal> and <literal>-l</literal> options allow you to specify where the information comes from, either the local machine or the default (or given) domain. The <literal>-o</literal> option allows for special cases (such as multiple domains) where the GIDs might match otherwise. The <literal>-s</literal> option omits the NT Security Identifier (SID). For more information on SIDs, see <Xref Linkend="ntsec"> in the Cygwin User's Guide. The <literal>-u</literal> option causes <command>mkgroup</command> to enumerate the users for each group, placing the group members in the gr_mem (last) field. Note that this can greatly increase the time for <command>mkgroup</command> to run in a large domain. </para> </sect2> <sect2 id="mkpasswd"><title>mkpasswd</title> <screen> Usage: mkpasswd [OPTION]... [domain] This program prints a /etc/passwd file to stdout Options: -l,--local print local user accounts -d,--domain print domain accounts (from current domain if no domain specified) -o,--id-offset offset change the default offset (10000) added to uids in domain accounts. -g,--local-groups print local group information too if no domain specified -m,--no-mount don't use mount points for home dir -s,--no-sids don't print SIDs in GCOS field (this affects ntsec) -p,--path-to-home path use specified path instead of user account home dir -u,--username username only return information for the specified user -h,--help displays this message -v,--version version information and exit One of `-l', `-d' or `-g' must be given on NT/W2K. </screen> <para>The <command>mkpasswd</command> program can be used to help configure your Windows system to be more UNIX-like by creating an initial <filename>/etc/passwd</filename> substitute (some commands need this file) from your system information. It only works on the NT series (Windows NT, 2000, and XP). <command>mkpasswd</command> does not work on the Win9x series (Windows 95, 98, and Me) because they lack the security model to support it. To initially set up your machine, you'd do something like this:</para> <example><title>Setting up the passwd file</title> <screen> <prompt>$</prompt> <userinput>mkdir /etc</userinput> <prompt>$</prompt> <userinput>mkpasswd -l > /etc/passwd</userinput> </screen> </example> <para>Note that this information is static. If you change the user information in your system, you'll need to regenerate the passwd file for it to have the new information.</para> <para>The <literal>-d</literal> and <literal>-l</literal> options allow you to specify where the information comes from, either the local machine or the default (or given) domain. The <literal>-o</literal> option allows for special cases (such as multiple domains) where the UIDs might match otherwise. The <literal>-g</literal> option creates a local user that corresponds to each local group. This is because NT assigns groups file ownership. The <literal>-m</literal> option bypasses the current mount table so that, for example, two users who have a Windows home directory of H: could mount them differently. The <literal>-s</literal> option omits the NT Security Identifier (SID). For more information on SIDs, see <Xref Linkend="ntsec"> in the Cygwin User's Guide. The <literal>-p</literal> option causes <command>mkpasswd</command> to use a prefix other than <literal>/home/</literal>. For example, this command: <example><title>Using an alternate home root</title> <screen> <prompt>$</prompt> <userinput>mkpasswd -l -p "$(cygpath -H)" > /etc/passwd</userinput> </screen> </example> would put local users' home directories in the Windows 'Profiles' directory. The <literal>-u</literal> option allows <command>mkpasswd</command> to search for a specific username, greatly reducing the amount of time it takes in a large domain.</para> </sect2> <sect2 id="mount"><title>mount</title> <screen> Usage: mount [OPTION] [<win32path> <posixpath>] -b, --binary text files are equivalent to binary files (newline = \n) -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-commands write mount commands to replace user and system mount points and cygdrive prefixes -p, --show-cygdrive-prefix show user and/or system cygdrive path prefix -s, --system (default) add system-wide mount point -t, --text (default) text files get \r\n line endings -u, --user add user-only mount point -v, --version output version information and exit -x, --executable treat all files under mount point as executables -E, --no-executable treat all files under mount point as non-executables -X, --cygwin-executable treat all files under mount point as cygwin executables </screen> <para>The <command>mount</command> program is used to map your drives and shares onto Cygwin's simulated POSIX directory tree, much like as is done by mount commands on typical UNIX systems. Please see <Xref Linkend="mount-table"> for more information on the concepts behind the Cygwin POSIX file system and strategies for using mounts. To remove mounts, use <command>umount</command></para> <sect3><title>Using mount</title> <para>If you just type <command>mount</command> with no parameters, it will display the current mount table for you.</para> <example> <title>Displaying the current set of mount points</title> <screen> <prompt>c:\cygwin\></prompt> <userinput>mount</userinput> c:\cygwin\bin on /usr/bin type system (binmode) c:\cygwin\lib on /usr/lib type system (binmode) c:\cygwin on / type system (binmode) c: on /c type user (binmode,noumount) d: on /d type user (binmode,noumount) </screen> </example> <para>In this example, c:\cygwin is the POSIX root and D drive is mapped to <filename>/d</filename>. Note that in this case, the root mount is a system-wide mount point that is visible to all users running Cygwin programs, whereas the <filename>/d</filename> mount is only visible to the current user.</para> <para>The <command>mount</command> utility is also the mechanism for adding new mounts to the mount table. The following example demonstrates how to mount the directory <filename>\\pollux\home\joe\data</filename> to <filename>/data</filename>. </para> <example> <title>Adding mount points</title> <screen> <prompt>c:\cygwin\></prompt> <userinput>ls /data</userinput> ls: /data: No such file or directory <prompt>c:\cygwin\></prompt> <userinput>mount \\pollux\home\joe\data /data</userinput> mount: warning - /data does not exist! <prompt>c:\cygwin\></prompt> <userinput>mount</userinput> \\pollux\home\joe\data on /data type sytem (binmode) c:\cygwin\bin on /usr/bin type system (binmode) c:\cygwin\lib on /usr/lib type system (binmode) c:\cygwin on / type system (binmode) c: on /c type user (binmode,noumount) d: on /d type user (binmode,noumount) </screen> </example> <para>Note that <command>mount</command> was invoked from the Windows command shell in the previous example. In many Unix shells, including bash, it is legal and convenient to use the forward "/" in Win32 pathnames since the "\" is the shell's escape character. </para> <para>The <literal>-s</literal> flag to <command>mount</command> is used to add a mount in the system-wide mount table used by all Cygwin users on the system, instead of the user-specific one. System-wide mounts are displayed by <command>mount</command> as being of the "system" type, as is the case for the <filename>/</filename> partition in the last example. Under Windows NT, only those users with Administrator priviledges are permitted to modify the system-wide mount table.</para> <para>Note that a given POSIX path may only exist once in the user table and once in the global, system-wide table. Attempts to replace the mount will fail with a busy error. The <literal>-f</literal> (force) flag causes the old mount to be silently replaced with the new one. It will also silence warnings about the non-existence of directories at the Win32 path location.</para> <para>The <literal>-b</literal> flag is used to instruct Cygwin to treat binary and text files in the same manner by default. Binary mode mounts are marked as "binmode" in the Flags column of <command>mount</command> output. By default, mounts are in text mode ("textmode" in the Flags column).</para> <para>Normally, files ending in certain extensions (.exe, .com, .bat, .cmd) are assumed to be executable. Files whose first two characters begin with '#!' are also considered to be executable. The <literal>-x</literal> flag is used to instruct Cygwin that the mounted file is "executable". If the <literal>-x</literal> flag is used with a directory then all files in the directory are executable. This option allows other files to be marked as executable and avoids the overhead of opening each file to check for a '#!'. The <literal>-X</literal> option is very similar to <literal>-x</literal>, but also prevents Cygwin from setting up commands and environment variables for a normal Windows program, adding another small performance gain. The opposite of these flags is the <literal>-E</literal> flag, which means that no files should be marked as executable. </para> <para> The <literal>-m</literal> option causes the <command>mount</command> utility to output a series of commands that could recreate both user and system mount points. You can save this output as a backup when experimenting with the mount table. It also makes moving your settings to a different machine much easier. </para> </sect3> <sect3><title>Cygdrive mount points</title> <para>Whenever Cygwin cannot use any of the existing mounts to convert from a particular Win32 path to a POSIX one, Cygwin will, instead, convert to a POSIX path using a default mount point: <filename>/cygdrive</filename>. For example, if Cygwin accesses <filename>z:\foo</filename> and the z drive is not currently in the mount table, then <filename>z:\</filename> will be accessible as <filename>/cygdrive/z</filename>. The <command>mount</command> utility can be used to change this default automount prefix through the use of the "--change-cygdrive-prefix" option. In the following example, we will set the automount prefix to <filename>/</filename>:</para> <example> <title>Changing the default prefix</title> <screen> <prompt>c:\cygwin\></prompt> <userinput>mount --change-cygdrive-prefix /</userinput> </screen> </example> <para>Note that you if you set a new prefix in this manner, you can specify the <literal>-s</literal> flag to make this the system-wide default prefix. By default, the cygdrive-prefix applies only to the current user. You can always see the user and system cygdrive prefixes with the <literal>-p</literal> option. Using the <literal>-b</literal> flag with <literal>--change-cygdrive-prefix</literal> makes all new automounted filesystems default to binary mode file accesses.</para> </sect3> <sect3><title>Limitations</title> <para>Limitations: there is a hard-coded limit of 30 mount points. Also, although you can mount to pathnames that do not start with "/", there is no way to make use of such mount points.</para> <para>Normally the POSIX mount point in Cygwin is an existing empty directory, as in standard UNIX. If this is the case, or if there is a place-holder for the mount point (such as a file, a symbolic link pointing anywhere, or a non-empty directory), you will get the expected behavior. Files present in a mount point directory before the mount become invisible to Cygwin programs. </para> <para>It is sometimes desirable to mount to a non-existent directory, for example to avoid cluttering the root directory with names such as <filename>a</filename>, <filename>b</filename>, <filename>c</filename> pointing to disks. Although <command>mount</command> will give you a warning, most everything will work properly when you refer to the mount point explicitly. Some strange effects can occur however. For example if your current working directory is <filename>/dir</filename>, say, and <filename>/dir/mtpt</filename> is a mount point, then <filename>mtpt</filename> will not show up in an <command>ls</command> or <command>echo *</command> command and <command>find .</command> will not find <filename>mtpt</filename>. </para> </sect3> </sect2> <sect2 id="passwd"><title>passwd</title> <screen> Usage: passwd (-l|-u|-S) [USER] passwd [-i NUM] [-n MINDAYS] [-x MAXDAYS] [-L LEN] User operations: -l, --lock lock USER's account -u, --unlock unlock USER's account -S, --status display password status for USER (locked, expired, etc.) System operations: -i, --inactive set NUM of days before inactive accounts are disabled (inactive accounts are those with expired passwords) -n, --minage set system minimum password age to MINDAYS -x, --maxage set system maximum password age to MAXDAYS -L, --length set system minimum password length to LEN Other options: -h, --help output usage information and exit -v, --version output version information and exit </screen> <para> <command>passwd</command> changes passwords for user accounts. A normal user may only change the password for their own account, but administrators may change passwords on any account. <command>passwd</command> also changes account information, such as password expiry dates and intervals.</para> <para>Password changes: The user is first prompted for their old password, if one is present. This password is then encrypted and compared against the stored password. The user has only one chance to enter the correct password. The administrators are permitted to bypass this step so that forgotten passwords may be changed.</para> <para>The user is then prompted for a replacement password. <command>passwd</command> will prompt twice for this replacement and compare the second entry against the first. Both entries are require to match in order for the password to be changed.</para> <para>After the password has been entered, password aging information is checked to see if the user is permitted to change their password at this time. If not, <command>passwd</command> refuses to change the password and exits.</para> <para>Account maintenance: User accounts may be locked and unlocked with the <literal>-l</literal> and <literal>-u</literal> flags. The <literal>-l</literal> option disables an account. The <literal>-u</literal> option re-enables an account.</para> <para>The account status may be given with the <literal>-S</literal> option. The status information is self explanatory.</para> <para>Administrators can also use <command>passwd</command> to change system-wide password expiry and length requirements with the <literal>-i</literal>, <literal>-n</literal>, <literal>-x</literal>, and <literal>-L</literal> options. The <literal>-i</literal> option is used to disable an account after the password has been expired for a number of days. After a user account has had an expired password for <emphasis>NUM</emphasis> days, the user may no longer sign on to the account. The <literal>-n</literal> option is used to set the minimum number of days before a password may be changed. The user will not be permitted to change the password until <emphasis>MINDAYS</emphasis> days have elapsed. The <literal>-x</literal> option is used to set the maximum number of days a password remains valid. After <emphasis>MAXDAYS</emphasis> days, the password is required to be changed. Allowed values for the above options are 0 to 999. The <literal>-L</literal> option sets the minimum length of allowed passwords for users who don't belong to the administrators group to <emphasis>LEN</emphasis> characters. Allowed values for the minimum password length are 0 to 14. In any of the above cases, a value of 0 means `no restrictions'.</para> <para>Limitations: Users may not be able to change their password on some systems.</para> </sect2> <sect2 id="ps"><title>ps</title> <screen> Usage: ps [-aefls] [-u UID] -a, --all show processes of all users -e, --everyone show processes of all users -f, --full show process uids, ppids -h, --help output usage information and exit -l, --long show process uids, ppids, pgids, winpids -s, --summary show process summary -u, --user list processes owned by UID -v, --version output version information and exit -W, --windows show windows as well as cygwin processes With no options, ps outputs the long format by default </screen> <para>The <command>ps</command> program gives the status of all the Cygwin processes running on the system (ps = "process status"). Due to the limitations of simulating a POSIX environment under Windows, there is little information to give. </para> <para> The PID column is the process ID you need to give to the <command>kill</command> command. The PPID is the parent process ID, and PGID is the process group ID. The WINPID column is the process ID displayed by NT's Task Manager program. The TTY column gives which pseudo-terminal a process is running on, or a <literal>'?'</literal> for services. The UID column shows which user owns each process. STIME is the time the process was started, and COMMAND gives the name of the program running. </para> <para> By default <command>ps</command> will only show processes owned by the current user. With either the <literal>-a</literal> or <literal>-e</literal> option, all user's processes (and system processes) are listed. There are historical UNIX reasons for the synonomous options, which are functionally identical. The <literal>-f</literal> option outputs a "full" listing with usernames for UIDs. The <literal>-l</literal> option is the default display mode, showing a "long" listing with all the above columns. The other display option is <literal>-s</literal>, which outputs a shorter listing of just PID, TTY, STIME, and COMMAND. The <literal>-u</literal> option allows you to show only processes owned by a specific user. The <literal>-W</literal> option causes <command>ps</command> show non-Cygwin Windows processes as well as Cygwin processes. The WINPID is also the PID, and they can be killed with the Cygwin <command>kill</command> command's <literal>-f</literal> option. </para> </sect2> <sect2 id="regtool"><title>regtool</title> <screen> Usage: regtool.exe [OPTION] (add | check | get | list | remove | unset) KEY Actions: add KEY\SUBKEY add new SUBKEY check KEY exit 0 if KEY exists, 1 if not get KEY\VALUE prints VALUE to stdout list KEY list SUBKEYs and VALUEs remove KEY remove KEY set KEY\VALUE [data ...] set VALUE unset KEY\VALUE removes VALUE from KEY Options for 'list' Action: -k, --keys print only KEYs -l, --list print only VALUEs -p, --postfix like ls -p, appends '\' postfix to KEY names Options for 'set' Action: -e, --expand-string set type to REG_EXPAND_SZ -i, --integer set type to REG_DWORD -m, --multi-string set type to REG_MULTI_SZ -s, --string set type to REG_SZ Other Options: -h, --help output usage information and exit -q, --quiet no error output, just nonzero return if KEY/VALUE missing -v, --verbose verbose output, including VALUE contents when applicable -V, --version output version information and exit KEY is in the format [host]\prefix\KEY\KEY\VALUE, where host is optional remote host in either \\hostname or hostname: format and prefix is any of: root HKCR HKEY_CLASSES_ROOT (local only) config HKCC HKEY_CURRENT_CONFIG (local only) user HKCU HKEY_CURRENT_USER (local only) machine HKLM HKEY_LOCAL_MACHINE users HKU HKEY_USERS You can use forward slash ('/') as a separator instead of backslash, in that case backslash is treated as escape character Example: regtool.exe get '\user\software\Microsoft\Clock\iFormat' </screen> <para>The <command>regtool</command> program allows shell scripts to access and modify the Windows registry. Note that modifying the Windows registry is dangerous, and carelessness here can result in an unusable system. Be careful.</para> <para>The <literal>-v</literal> option means "verbose". For most commands, this causes additional or lengthier messages to be printed. Conversely, the <literal>-q</literal> option supresses error messages, so you can use the exit status of the program to detect if a key exists or not (for example).</para> <para>You must provide <command>regtool</command> with an <emphasis>action</emphasis> following options (if any). Currently, the action must be <literal>add</literal>, <literal>set</literal>, <literal>check</literal>, <literal>get</literal>, <literal>list</literal>, <literal>remove</literal>, <literal>set</literal>, or <literal>unset</literal>. </para> <para>The <literal>add</literal> action adds a new key. The <literal>check</literal> action checks to see if a key exists (the exit code of the program is zero if it does, nonzero if it does not). The <literal>get</literal> action gets the value of a value of a key, and prints it (and nothing else) to stdout. Note: if the value doesn't exist, an error message is printed and the program returns a non-zero exit code. If you give <literal>-q</literal>, it doesn't print the message but does return the non-zero exit code.</para> <para> The <literal>list</literal> action lists the subkeys and values belonging to the given key. With <literal>list</literal>, the <literal>-k</literal> option instructs <command>regtool</command> to print only KEYs, and the <literal>-l</literal> option to print only VALUEs. The <literal>-p</literal> option postfixes a <literal>'/'</literal> to each KEY, but leave VALUEs with no postfix. The <literal>remove</literal> action removes a key. Note that you may need to remove everything in the key before you may remove it, but don't rely on this stopping you from accidentally removing too much. </para> <para>The <literal>set</literal> action sets a value within a key. <literal>-e</literal> means it's an expanding string (REG_EXPAND_SZ) that contains embedded environment variables. <literal>-i</literal> means the value is an integer (REG_DWORD). <literal>-m</literal> means it's a multi-string (REG_MULTI_SZ). <literal>-s</literal> means the value is a string (REG_SZ). If you don't specify one of these, <command>regtool</command> tries to guess the type based on the value you give. If it looks like a number, it's a DWORD. If it starts with a percent, it's an expanding string. If you give multiple values, it's a multi-string. Else, it's a regular string. The <literal>unset</literal> action removes a value from a key. </para> </sect2> <sect2 id="setfacl"><title>setfacl</title> <screen> Usage: setfacl [-r] (-f ACL_FILE | -s acl_entries) FILE... setfacl [-r] ([-d acl_entries] [-m acl_entries]) FILE... Modify file and directory access control lists (ACLs) -d, --delete delete one or more specified ACL entries -f, --file set ACL entries for FILE to ACL entries read from a ACL_FILE -m, --modify modify one or more specified ACL entries -r, --replace replace mask entry with maximum permissions needed for the file group class -s, --substitute substitute specified ACL entries for the ACL of FILE -h, --help output usage information and exit -v, --version output version information and exit At least one of (-d, -f, -m, -s) must be specified </screen> <para> For each file given as parameter, <command>setfacl</command> will either replace its complete ACL (<literal>-s</literal>, <literal>-f</literal>), or it will add, modify, or delete ACL entries. For more information on Cygwin and Windows ACLs, see see <Xref Linkend="ntsec"> in the Cygwin User's Guide. </para> <para> Acl_entries are one or more comma-separated ACL entries from the following list: <screen> u[ser]::perm u[ser]:uid:perm g[roup]::perm g[roup]:gid:perm m[ask]::perm o[ther]::perm </screen> Default entries are like the above with the additional default identifier. For example: <screen> d[efault]:u[ser]:uid:perm </screen> </para> <para> <emphasis>perm</emphasis> is either a 3-char permissions string in the form "rwx" with the character <literal>'-'</literal> for no permission or it is the octal representation of the permissions, a value from 0 (equivalent to "---") to 7 ("rwx"). <emphasis>uid</emphasis> is a user name or a numerical uid. <emphasis>gid</emphasis> is a group name or a numerical gid. </para> <para> The following options are supported: </para> <para> <literal>-d</literal> Delete one or more specified entries from the file's ACL. The owner, group and others entries must not be deleted. Acl_entries to be deleted should be specified without permissions, as in the following list: <screen> u[ser]:uid g[roup]:gid d[efault]:u[ser]:uid d[efault]:g[roup]:gid d[efault]:m[ask]: d[efault]:o[ther]: </screen> </para> <para> <literal>-f</literal> Take the Acl_entries from ACL_FILE one per line. Whitespace characters are ignored, and the character "#" may be used to start a comment. The special filename "-" indicates reading from stdin. Note that you can use this with <command>getfacl</command> and <command>setfacl</command> to copy ACLs from one file to another: <screen> $ getfacl source_file | setfacl -f - target_file </screen> </para> <para> Required entries are: one user entry for the owner of the file, one group entry for the group of the file, and one other entry. </para> <para> If additional user and group entries are given: a mask entry for the file group class of the file, and no duplicate user or group entries with the same uid/gid. </para> <para> If it is a directory: one default user entry for the owner of the file, one default group entry for the group of the file, one default mask entry for the file group class, and one default other entry. </para> <para> <literal>-m</literal> Add or modify one or more specified ACL entries. Acl_entries is a comma-separated list of entries from the same list as above. </para> <para> <literal>-r</literal> Causes the permissions specified in the mask entry to be ignored and replaced by the maximum permissions needed for the file group class. </para> <para> <literal>-s</literal> Like <literal>-f</literal>, but substitute the file's ACL with Acl_entries specified in a comma-separated list on the command line. </para> <para> While the <literal>-d</literal> and <literal>-m</literal> options may be used in the same command, the <literal>-f</literal> and <literal>-s</literal> options may be used only exclusively. </para> <para> Directories may contain default ACL entries. Files created in a directory that contains default ACL entries will have permissions according to the combination of the current umask, the explicit permissions requested and the default ACL entries </para> <para> Limitations: Under Cygwin, the default ACL entries are not taken into account currently. </para> </sect2> <sect2 id="ssp"><title>ssp</title> <screen> Usage: ssp [options] low_pc high_pc command... -c, --console-trace trace every EIP value to the console. *Lots* slower. -d, --disable disable single-stepping by default; use OutputDebugString ("ssp on") to enable stepping -e, --enable enable single-stepping by default; use OutputDebugString ("ssp off") to disable stepping -h, --help output usage information and exit -l, --dll enable dll profiling. A chart of relative DLL usage is produced after the run. -s, --sub-threads trace sub-threads too. Dangerous if you have race conditions. -t, --trace-eip trace every EIP value to a file TRACE.SSP. This gets big *fast*. -v, --verbose output verbose messages about debug events. -V, --version output version information and exit Example: ssp 0x401000 0x403000 hello.exe </screen> <para> SSP - The Single Step Profiler </para> <para> Original Author: DJ Delorie </para> <para> The SSP is a program that uses the Win32 debug API to run a program one ASM instruction at a time. It records the location of each instruction used, how many times that instruction is used, and all function calls. The results are saved in a format that is usable by the profiling program <command>gprof</command>, although <command>gprof</command> will claim the values are seconds, they really are instruction counts. More on that later. </para> <para> Because the SSP was originally designed to profile the cygwin DLL, it does not automatically select a block of code to report statistics on. You must specify the range of memory addresses to keep track of manually, but it's not hard to figure out what to specify. Use the "objdump" program to determine the bounds of the target's ".text" section. Let's say we're profiling cygwin1.dll. Make sure you've built it with debug symbols (else <command>gprof</command> won't run) and run objdump like this: <screen> $ objdump -h cygwin1.dll </screen> It will print a report like this: <screen> cygwin1.dll: file format pei-i386 Sections: Idx Name Size VMA LMA File off Algn 0 .text 0007ea00 61001000 61001000 00000400 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE, DATA 1 .data 00008000 61080000 61080000 0007ee00 2**2 CONTENTS, ALLOC, LOAD, DATA . . . </screen> </para> <para> The only information we're concerned with are the VMA of the .text section and the VMA of the section after it (sections are usually contiguous; you can also add the Size to the VMA to get the end address). In this case, the VMA is 0x61001000 and the ending address is either 0x61080000 (start of .data method) or 0x0x6107fa00 (VMA+Size method). </para> <para> There are two basic ways to use SSP - either profiling a whole program, or selectively profiling parts of the program. </para> <para> To profile a whole program, just run <command>ssp</command> without options. By default, it will step the whole program. Here's a simple example, using the numbers above: <screen> $ ssp 0x61001000 0x61080000 hello.exe </screen> This will step the whole program. It will take at least 8 minutes on a PII/300 (yes, really). When it's done, it will create a file called "gmon.out". You can turn this data file into a readable report with <command>gprof</command>: <screen> $ gprof -b cygwin1.dll </screen> The "-b" means 'skip the help pages'. You can omit this until you're familiar with the report layout. The <command>gprof</command> documentation explains a lot about this report, but <command>ssp</command> changes a few things. For example, the first part of the report reports the amount of time spent in each function, like this: <screen> Each sample counts as 0.01 seconds. % cumulative self self total time seconds seconds calls ms/call ms/call name 10.02 231.22 72.43 46 1574.57 1574.57 strcspn 7.95 288.70 57.48 130 442.15 442.15 strncasematch </screen> The "seconds" columns are really CPU opcodes, 1/100 second per opcode. So, "231.22" above means 23,122 opcodes. The ms/call values are 10x too big; 1574.57 means 157.457 opcodes per call. Similar adjustments need to be made for the "self" and "children" columns in the second part of the report. </para> <para> OK, so now we've got a huge report that took a long time to generate, and we've identified a spot we want to work on optimizing. Let's say it's the time() function. We can use SSP to selectively profile this function by using OutputDebugString() to control SSP from within the program. Here's a sample program: <screen> #include <windows.h> main() { time_t t; OutputDebugString("ssp on"); time(&t); OutputDebugString("ssp off"); } </screen> </para> <para> Then, add the <literal>-d</literal> option to ssp to default to *disabling* profiling. The program will run at full speed until the first OutputDebugString, then step until the second. You can then use <command>gprof</command> (as usual) to see the performance profile for just that portion of the program's execution. </para> <para> There are many options to ssp. Since step-profiling makes your program run about 1,000 times slower than normal, it's best to understand all the options so that you can narrow down the parts of your program you need to single-step. </para> <para> <literal>-v</literal> - verbose. This prints messages about threads starting and stopping, OutputDebugString calls, DLLs loading, etc. </para> <para> <literal>-t</literal> and <literal>-c</literal> - tracing. With <literal>-t</literal>, *every* step's address is written to the file "trace.ssp". This can be used to help debug functions, since it can trace multiple threads. Clever use of scripts can match addresses with disassembled opcodes if needed. Warning: creates *huge* files, very quickly. <literal>-c</literal> prints each address to the console, useful for debugging key chunks of assembler. Use <literal>addr2line -C -f -s -e foo.exe < trace.ssp > lines.ssp</literal> and then <literal>perl cvttrace</literal> to convert to symbolic traces. </para> <para> <literal>-s</literal> - subthreads. Usually, you only need to trace the main thread, but sometimes you need to trace all threads, so this enables that. It's also needed when you want to profile a function that only a subthread calls. However, using OutputDebugString automatically enables profiling on the thread that called it, not the main thread. </para> <para> <literal>-l</literal> - dll profiling. Generates a pretty table of how much time was spent in each dll the program used. No sense optimizing a function in your program if most of the time is spent in the DLL. I usually use the <literal>-v</literal>, <literal>-s</literal>, and <literal>-l</literal> options: <screen> $ ssp <literal>-v</literal> <literal>-s</literal> <literal>-l</literal> <literal>-d</literal> 0x61001000 0x61080000 hello.exe </screen> </para> </sect2> <sect2 id="strace"><title>strace</title> <screen> Usage: strace.exe [OPTIONS] <command-line> Usage: strace.exe [OPTIONS] -p <pid> -b, --buffer-size=SIZE set size of output file buffer -d, --no-delta don't display the delta-t microsecond timestamp -f, --trace-children trace child processes (toggle - default true) -h, --help output usage information and exit -m, --mask=MASK set message filter mask -n, --crack-error-numbers output descriptive text instead of error numbers for Windows errors -o, --output=FILENAME set output file to FILENAME -p, --pid=n attach to executing program with cygwin pid n -S, --flush-period=PERIOD flush buffered strace output every PERIOD secs -t, --timestamp use an absolute hh:mm:ss timestamp insted of the default microsecond timestamp. Implies -d -T, --toggle toggle tracing in a process already being 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. </screen> <para>The <command>strace</command> program executes a program, and optionally the children of the program, reporting any Cygwin DLL output from the program(s) to stdout, or to a file with the <literal>-o</literal> option. With the <literal>-w</literal> option, you can start an strace session in a new window, for example: <screen> $ strace -o tracing_output -w sh -c 'while true; do echo "tracing..."; done' & </screen> This is particularly useful for <command>strace</command> sessions that take a long time to complete. </para> <para> Note that <command>strace</command> is a standalone Windows program and so does not rely on the Cygwin DLL itself (you can verify this with <command>cygcheck</command>). As a result it does not understand POSIX pathnames or symlinks. This program is mainly useful for debugging the Cygwin DLL itself.</para> </sect2> <sect2 id="umount"><title>umount</title> <screen> Usage: umount.exe [OPTION] [<posixpath>] -A, --remove-all-mounts remove all mounts -c, --remove-cygdrive-prefix remove cygdrive prefix -h, --help output usage information and exit -s, --system remove system mount (default) -S, --remove-system-mounts remove all system mounts -u, --user remove user mount -U, --remove-user-mounts remove all user mounts -v, --version output version information and exit </screen> <para>The <command>umount</command> program removes mounts from the mount table. If you specify a POSIX path that corresponds to a current mount point, <command>umount</command> will remove it from the system registry area. (Administrator priviledges are required). The <literal>-u</literal> flag may be used to specify removing the mount from the user-specific registry area instead.</para> <para>The <command>umount</command> utility may also be used to remove all mounts of a particular type. With the extended options it is possible to remove all mounts (<literal>-A</literal>), all cygdrive automatically-mounted mounts (<literal>-c</literal>), all mounts in the current user's registry area (<literal>-U</literal>), or all mounts in the system-wide registry area (<literal>-S</literal>) (with Administrator privileges).</para> <para>See <Xref Linkend="mount"> for more information on the mount table.</para> </sect2> </sect1>