neulab/tldr huggingface dataset:
-m, --move-home Move the content of the user's home directory to the new location.
This option is only valid in combination with the -d (or --home) option.
usermod will try to adapt the ownership of the files and to copy the modes, ACL and extended attributes, but manual changes might be needed afterwards.
-o, --non-unique When used with the -u option, this option allows to change the user ID to a non-unique value.
-p, --password PASSWORD The encrypted password, as returned by crypt(3).
Note: This option is not recommended because the password (or encrypted password) will be visible by users listing the processes.
You should make sure the password respects the system's password policy.
-R, --root CHROOT_DIR Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.
-P, --prefix PREFIX_DIR Apply changes in the PREFIX_DIR directory and use the configuration files from the PREFIX_DIR directory. This option does not chroot and is intended for preparing a cross-compilation target. Some limitations: NIS and LDAP users/groups are not verified. PAM authentication is using the host files. No SELINUX support.
-s, --shell SHELL The name of the user's new login shell. Setting this field to blank causes the system to select the default login shell.
-u, --uid UID The new numerical value of the user's ID.
This value must be unique, unless the -o option is used. The value must be non-negative.
The user's mailbox, and any files which the user owns and which are located in the user's home directory will have the file user ID changed automatically.
The ownership of files outside of the user's home directory must be fixed manually.
No checks will be performed with regard to the UID_MIN, UID_MAX, SYS_UID_MIN, or SYS_UID_MAX from /etc/login.defs.
-U, --unlock Unlock a user's password. This removes the '!' in front of the encrypted password. You can't use this option with -p or -L.
Note: if you wish to unlock the account (not only access with a password), you should also set the EXPIRE_DATE (for example to 99999, or to the EXPIRE value from /etc/default/useradd).
-v, --add-subuids FIRST-LAST Add a range of subordinate uids to the user's account.
This option may be specified multiple times to add multiple ranges to a users account.
No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from /etc/login.defs.
-V, --del-subuids FIRST-LAST Remove a range of subordinate uids from the user's account.
This option may be specified multiple times to remove multiple ranges to a users account. When both --del-subuids and --add-subuids are specified, the removal of all subordinate uid ranges happens before any subordinate uid range is added.
-w, --add-subgids FIRST-LAST Add a range of subordinate gids to the user's account.
No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from /etc/login.defs.
-W, --del-subgids FIRST-LAST Remove a range of subordinate gids from the user's account.
This option may be specified multiple times to remove multiple ranges to a users account. When both --del-subgids and --add-subgids are specified, the removal of all subordinate gid ranges happens before any subordinate gid range is added.
-Z, --selinux-user SEUSER The new SELinux user for the user's login.
A blank SEUSER will remove the SELinux user mapping for user LOGIN (if any).
You must make certain that the named user is not executing any processes when this command is being executed if the user's numerical user ID, the user's name, or the user's home directory is being changed.  usermod checks this on Linux. On other platforms it only uses utmp to check if the user is logged in.
You must change the owner of any crontab files or at jobs manually.
You must make any changes involving NIS on the NIS server.
The following configuration variables in /etc/login.defs change the behavior of this tool:
LASTLOG_UID_MAX (number) Highest user ID number for which the lastlog entries should be updated. As higher user IDs are usually tracked by remote user identity and authentication services there is no need to create a huge sparse lastlog file for them.
No LASTLOG_UID_MAX option present in the configuration means that there is no user ID limit for writing lastlog entries.
MAIL_DIR (string) The mail spool directory. This is needed to manipulate the mailbox when its corresponding user account is modified or deleted. If not specified, a compile-time default is used.
MAIL_FILE (string) Defines the location of the users mail spool files relatively to their home directory.
The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod, and userdel to create, move, or delete the user's mail spool.
If MAIL_CHECK_ENAB is set to yes, they are also used to define the MAIL environment variable.
MAX_MEMBERS_PER_GROUP (number) Maximum members per group entry. When the maximum is reached, a new group entry (line) is started in /etc/group (with the same name, same password, and same GID).
The default value is 0, meaning that there are no limits in the number of members in a group.
This feature (split group) permits to limit the length of lines in the group file. This is useful to make sure that lines for NIS groups are not larger than 1024 characters.
If you need to enforce such limit, you can use 25.
Note: split groups may not be supported by all tools (even in the Shadow toolsuite). You should not use this variable unless you really need it.
SUB_GID_MIN (number), SUB_GID_MAX (number), SUB_GID_COUNT (number) If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate group IDs) allocate SUB_GID_COUNT unused group IDs from the range SUB_GID_MIN to SUB_GID_MAX for each new user.
The default values for SUB_GID_MIN, SUB_GID_MAX, SUB_GID_COUNT are respectively 100000, 600100000 and 65536.
SUB_UID_MIN (number), SUB_UID_MAX (number), SUB_UID_COUNT (number) If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate user IDs) allocate SUB_UID_COUNT unused user IDs from the range SUB_UID_MIN to SUB_UID_MAX for each new user.
The default values for SUB_UID_MIN, SUB_UID_MAX, SUB_UID_COUNT are respectively 100000, 600100000 and 65536.
/etc/group Group account information.
/etc/gshadow Secure group account information.
/etc/login.defs Shadow password suite configuration.
/etc/passwd User account information.
/etc/shadow Secure user account information.
/etc/subgid Per user subordinate group IDs.
/etc/subuid Per user subordinate user IDs.
chfn(1), chsh(1), passwd(1), crypt(3), gpasswd(8), groupadd(8), groupdel(8), groupmod(8), login.defs(5), subgid(5), subuid(5), useradd(8), userdel(8).
UDEVADM(8)                           udevadm                          UDEVADM(8)
udevadm - udev management tool
udevadm [--debug] [--version] [--help]
udevadm info [options] [devpath]
udevadm trigger [options] [devpath]
udevadm settle [options]
udevadm control option
udevadm monitor [options]
udevadm test [options] devpath
udevadm test-builtin [options] command devpath
udevadm expects a command and command specific options. It controls the runtime behavior of systemd-udevd, requests kernel events, manages the event queue, and provides simple debugging mechanisms.
-d, --debug Print debug messages to standard error. This option is implied in udevadm test and udevadm test-builtin commands.
-h, --help Print a short help text and exit.
udevadm info [options] [devpath|file|unit...] Query the udev database for device information.
Positional arguments should be used to specify one or more devices. Each one may be a device name (in which case it must start with /dev/), a sys path (in which case it must start with /sys/), or a systemd device unit name (in which case it must end with ".device", see systemd.device(5)).
-q, --query=TYPE Query the database for the specified type of device data. Valid TYPEs are: name, symlink, path, property, all.
-p, --path=DEVPATH The /sys/ path of the device to query, e.g.  [/sys/]/class/block/sda. This option is an alternative to the positional argument with a /sys/ prefix.  udevadm info --path=/class/block/sda is equivalent to udevadm info /sys/class/block/sda.
-n, --name=FILE The name of the device node or a symlink to query, e.g.  [/dev/]/sda. This option is an alternative to the positional argument with a /dev/ prefix.  udevadm info --name=sda is equivalent to udevadm info /dev/sda.
-r, --root Print absolute paths in name or symlink query.
-a, --attribute-walk Print all sysfs properties of the specified device that can be used in udev rules to match the specified device. It prints all devices along the chain, up to the root of sysfs that can be used in udev rules.
-x, --export Print output as key/value pairs. Values are enclosed in single quotes. This takes effects only when --query=property or --device-id-of-file=FILE is specified.
-P, --export-prefix=NAME Add a prefix to the key name of exported values. This implies --export.
-d, --device-id-of-file=FILE Print major/minor numbers of the underlying device, where the file lives on. If this is specified, all positional arguments are ignored.
-e, --export-db Export the content of the udev database.
-c, --cleanup-db Cleanup the udev database.
-w[SECONDS], --wait-for-initialization[=SECONDS] Wait for device to be initialized. If argument SECONDS is not specified, the default is to wait forever.
The generated output shows the current device database entry in a terse format. Each line shown is prefixed with one of the following characters:
Table 1. udevadm info output prefixes ┌───────┬─────────────────────────┐ │Prefix │ Meaning                 │ ├───────┼─────────────────────────┤ │"P:"   │ Device path in /sys/    │ ├───────┼─────────────────────────┤ │"N:"   │ Kernel device node name │ ├───────┼─────────────────────────┤ │"L:"   │ Device node symlink     │ │       │ priority                │ ├───────┼─────────────────────────┤ │"S:"   │ Device node symlink     │ ├───────┼─────────────────────────┤ │"E:"   │ Device property         │ └───────┴─────────────────────────┘
udevadm trigger [options] [devpath|file|unit] Request device events from the kernel. Primarily used to replay events at system coldplug time.
Takes device specifications as positional arguments. See the description of info above.
-v, --verbose Print the list of devices which will be triggered.
-n, --dry-run Do not actually trigger the event.
-q, --quiet Suppress error logging in triggering events.
-t, --type=TYPE Trigger a specific type of devices. Valid types are: devices, subsystems. The default value is devices.
-c, --action=ACTION Type of event to be triggered. Possible actions are "add", "remove", "change", "move", "online", "offline", "bind", and "unbind". Also, the special value "help" can be used to list the possible actions. The default value is "change".
-s, --subsystem-match=SUBSYSTEM Trigger events for devices which belong to a matching subsystem. This option supports shell style pattern matching. When this option is specified more than once, then each matching result is ORed, that is, all the devices in each subsystem are triggered.
-S, --subsystem-nomatch=SUBSYSTEM Do not trigger events for devices which belong to a matching subsystem. This option supports shell style pattern matching. When this option is specified more than once, then each matching result is ANDed, that is, devices which do not match all specified subsystems are triggered.
-a, --attr-match=ATTRIBUTE=VALUE Trigger events for devices with a matching sysfs attribute. If a value is specified along with the attribute name, the content of the attribute is matched against the given value using shell style pattern matching. If no value is specified, the existence of the sysfs attribute is checked. When this option is specified multiple times, then each matching result is ANDed, that is, only devices which have all specified attributes are triggered.
-A, --attr-nomatch=ATTRIBUTE=VALUE Do not trigger events for devices with a matching sysfs attribute. If a value is specified along with the attribute name, the content of the attribute is matched against the given value using shell style pattern matching. If no value is specified, the existence of the sysfs attribute is checked. When this option is specified multiple times, then each matching result is ANDed, that is, only devices which have none of the specified attributes are triggered.
-p, --property-match=PROPERTY=VALUE Trigger events for devices with a matching property value. This option supports shell style pattern matching. When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the specified properties are triggered.
-g, --tag-match=TAG Trigger events for devices with a matching tag. When this option is specified multiple times, then each matching result is ANDed, that is, devices which have all specified tags are triggered.
-y, --sysname-match=NAME Trigger events for devices for which the last component (i.e. the filename) of the /sys/ path matches the specified PATH. This option supports shell style pattern matching. When this option is specified more than once, then each matching result is ORed, that is, all devices which have any of the specified NAME are triggered.
--name-match=NAME Trigger events for devices with a matching device path. When this option is specified more than once, then each matching result is ORed, that is, all specified devices are triggered.
-b, --parent-match=SYSPATH Trigger events for all children of a given device. When this option is specified more than once, then each matching result is ORed, that is, all children of each specified device are triggered.
-w, --settle Apart from triggering events, also waits for those events to finish. Note that this is different from calling udevadm settle.  udevadm settle waits for all events to finish. This option only waits for events triggered by the same command to finish.
--uuid Trigger the synthetic device events, and associate a randomized UUID with each. These UUIDs are printed to standard output, one line for each event. These UUIDs are included in the uevent environment block (in the "SYNTH_UUID=" property) and may be used to track delivery of the generated events.
--wait-daemon[=SECONDS] Before triggering uevents, wait for systemd-udevd daemon to be initialized. Optionally takes timeout value. Default timeout is 5 seconds. This is equivalent to invoke invoking udevadm control --ping before udevadm trigger.
In addition, optional positional arguments can be used to specify device names or sys paths. They must start with /dev/ or /sys/ respectively.
udevadm settle [options] Watches the udev event queue, and exits if all current events are handled.
-t, --timeout=SECONDS Maximum number of seconds to wait for the event queue to become empty. The default value is 120 seconds. A value of 0 will check if the queue is empty and always return immediately. A non-zero value will return an exit code of 0 if queue became empty before timeout was reached, non-zero otherwise.
-E, --exit-if-exists=FILE Stop waiting if file exists.
See systemd-udev-settle.service(8) for more information.
udevadm control option Modify the internal state of the running udev daemon.
-e, --exit Signal and wait for systemd-udevd to exit. No option except for --timeout can be specified after this option. Note that systemd-udevd.service contains Restart=always and so as a result, this option restarts systemd-udevd. If you want to stop systemd-udevd.service, please use the following:
systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service
-l, --log-level=value Set the internal log level of systemd-udevd. Valid values are the numerical syslog priorities or their textual representations: emerg, alert, crit, err, warning, notice, info, and debug.
-s, --stop-exec-queue Signal systemd-udevd to stop executing new events. Incoming events will be queued.
-S, --start-exec-queue Signal systemd-udevd to enable the execution of events.
-R, --reload Signal systemd-udevd to reload the rules files and other databases like the kernel module index. Reloading rules and databases does not apply any changes to already existing devices; the new configuration will only be applied to new events.
-p, --property=KEY=value Set a global property for all events.
-m, --children-max=value Set the maximum number of events, systemd-udevd will handle at the same time.
--ping Send a ping message to systemd-udevd and wait for the reply. This may be useful to check that systemd-udevd daemon is running.
-t, --timeout=seconds The maximum number of seconds to wait for a reply from systemd-udevd.
udevadm monitor [options] Listens to the kernel uevents and events sent out by a udev rule and prints the devpath of the event to the console. It can be used to analyze the event timing, by comparing the timestamps of the kernel uevent and the udev event.
-k, --kernel Print the kernel uevents.
-u, --udev Print the udev event after the rule processing.
-p, --property Also print the properties of the event.
-s, --subsystem-match=string[/string] Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass. When this option is specified more than once, then each matching result is ORed, that is, all devices in the specified subsystems are monitored.
-t, --tag-match=string Filter udev events by tag. Only udev events with a given tag attached will pass. When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the specified tags are monitored.
udevadm test [options] [devpath] Simulate a udev event run for the given device, and print debug output.
-a, --action=ACTION Type of event to be simulated. Possible actions are "add", "remove", "change", "move", "online", "offline", "bind", and "unbind". Also, the special value "help" can be used to list the possible actions. The default value is "add".
-N, --resolve-names=early|late|never Specify when udevadm should resolve names of users and groups. When set to early (the default), names will be resolved when the rules are parsed. When set to late, names will be resolved for every event. When set to never, names will never be resolved and all devices will be owned by root.
udevadm test-builtin [options] [command] [devpath] Run a built-in command COMMAND for device DEVPATH, and print debug output.
udev(7), systemd-udevd.service(8)
dhclient(8)                  System Manager's Manual                 dhclient(8)
dhclient - Dynamic Host Configuration Protocol Client
dhclient [ -4 | -6 ] [ -S ] [ -N [ -N...  ] ] [ -T [ -T...  ] ] [ -P [ -P...  ] ] [ -R ] [ -i ] [ -I ] [ -4o6 port ] [ -D LL|LLT ] [ -p port- number ] [ -d ] [ -df duid-lease-file ] [ -e VAR=value ] [ -q ] [ -1 ] [ -r | -x ] [ -lf lease-file ] [ -pf pid-file ] [ --no-pid ] [ -cf config- file ] [ -sf script-file ] [ -s server-addr ] [ -g relay ] [ -n ] [ -nw ] [ -w ] [ --dad-wait-time seconds ] [ --prefix-len-hint length ] [ --decline-wait-time seconds ] [ -v ] [ --version ] [ if0 [ ...ifN ] ]
The Internet Systems Consortium DHCP Client, dhclient, provides a means for configuring one or more network interfaces using the Dynamic Host Configuration Protocol, BOOTP protocol, or if these protocols fail, by statically assigning an address.
The DHCP protocol allows a host to contact a central server which maintains a list of IP addresses which may be assigned on one or more subnets.  A DHCP client may request an address from this pool, and then use it on a temporary basis for communication on network.  The DHCP protocol also provides a mechanism whereby a client can learn important details about the network to which it is attached, such as the location of a default router, the location of a name server, and so on.
There are two versions of the DHCP protocol DHCPv4 and DHCPv6.  At startup the client may be started for one or the other via the -4 or -6 options.
On startup, dhclient reads the dhclient.conf for configuration instructions.  It then gets a list of all the network interfaces that are configured in the current system.  For each interface, it attempts to configure the interface using the DHCP protocol.
In order to keep track of leases across system reboots and server restarts, dhclient keeps a list of leases it has been assigned in the dhclient.leases file.  On startup, after reading the dhclient.conf file, dhclient reads the dhclient.leases file to refresh its memory about what leases it has been assigned.
When a new lease is acquired, it is appended to the end of the dhclient.leases file.  In order to prevent the file from becoming arbitrarily large, from time to time dhclient creates a new dhclient.leases file from its in-core lease database.  The old version of the dhclient.leases file is retained under the name dhclient.leases~ until the next time dhclient rewrites the database.
Old leases are kept around in case the DHCP server is unavailable when dhclient is first invoked (generally during the initial system boot process).  In that event, old leases from the dhclient.leases file which have not yet expired are tested, and if they are determined to be valid, they are used until either they expire or the DHCP server becomes available.
A mobile host which may sometimes need to access a network on which no DHCP server exists may be preloaded with a lease for a fixed address on that network.  When all attempts to contact a DHCP server have failed, dhclient will try to validate the static lease, and if it succeeds, will use that lease until it is restarted.
A mobile host may also travel to some networks on which DHCP is not available but BOOTP is.  In that case, it may be advantageous to arrange with the network administrator for an entry on the BOOTP database, so that the host can boot quickly on that network rather than cycling through the list of old leases.
The names of the network interfaces that dhclient should attempt to configure may be specified on the command line.  If no interface names are specified on the command line dhclient will normally identify all network interfaces, eliminating non-broadcast interfaces if possible, and attempt to configure each interface.
It is also possible to specify interfaces by name in the dhclient.conf file.  If interfaces are specified in this way, then the client will only configure interfaces that are either specified in the configuration file or on the command line, and will ignore all other interfaces.
The client normally prints no output during its startup sequence.  It can be made to emit verbose messages displaying the startup sequence events until it has acquired an address by supplying the -v command line argument.  In either case, the client logs messages using the syslog(3) facility.
-4     Use the DHCPv4 protocol to obtain an IPv4 address and configuration parameters.  This is the default and cannot be combined with -6.
-6     Use the DHCPv6 protocol to obtain whatever IPv6 addresses are available along with configuration parameters.  It cannot be combined with -4.  The -S -T -P -N and -D arguments provide more control over aspects of the DHCPv6 processing.  Note: it is not recommended to mix queries of different types together or even to share the lease file between them.
-4o6 port Participate in the DHCPv4 over DHCPv6 protocol specified by RFC 7341.  This associates a DHCPv4 and a DHCPv6 client to allow the v4 client to send v4 requests encapsulated in a v6 packet. Communication between the two clients is done on a pair of UDP sockets bound to ::1 port and port + 1. Both clients must be launched using the same port argument.
-1     Try to get a lease once.  On failure exit with code 2.  In DHCPv6 this sets the maximum duration of the initial exchange to timeout (from dhclient.conf with a default of sixty seconds).
-d     Force dhclient to run as a foreground process.  Normally the DHCP client will run in the foreground until is has configured an interface at which time it will revert to running in the background.  This option is useful when running the client under a debugger, or when running it out of inittab on System V systems. This implies -v.
-nw    Become a daemon immediately (nowait) rather than waiting until an IP address has been acquired.
-q     Be quiet at startup, this is the default.
-v     Enable verbose log messages.
-w     Continue running even if no broadcast interfaces were found. Normally DHCP client will exit if it isn't able to identify any network interfaces to configure.  On laptop computers and other computers with hot-swappable I/O buses, it is possible that a broadcast interface may be added after system startup.  This flag can be used to cause the client not to exit when it doesn't find any such interfaces.  The omshell(1) program can then be used to notify the client when a network interface has been added or removed, so that the client can attempt to configure an IP address on that interface.
-n     Do not configure any interfaces.  This is most likely to be useful in combination with the -w flag.
-e VAR=value Define additional environment variables for the environment where dhclient-script executes.  You may specify multiple -e options on the command line.
-r     Release the current lease and stop the running DHCP client as previously recorded in the PID file.  When shutdown via this method dhclient-script will be executed with the specific reason for calling the script set.  The client normally doesn't release the current lease as this is not required by the DHCP protocol but some cable ISPs require their clients to notify the server if they wish to release an assigned IP address.
-x     Stop the running DHCP client without releasing the current lease. Kills existing dhclient process as previously recorded in the PID file.  When shutdown via this method dhclient-script will be executed with the specific reason for calling the script set.
-p port-number The UDP port number on which the DHCP client should listen and transmit.  If unspecified, dhclient uses the default port of 68. This is mostly useful for debugging purposes.  If a different port is specified on which the client should listen and transmit, the client will also use a different destination port - one less than the specified port.
-s server-addr Specify the server IP address or fully qualified domain name to use as a destination for DHCP protocol messages before dhclient has acquired an IP address.  Normally, dhclient transmits these messages to 255.255.255.255 (the IP limited broadcast address). Overriding this is mostly useful for debugging purposes.  This feature is not supported in DHCPv6 (-6) mode.
-g relay Set the giaddr field of all packets to the relay IP address simulating a relay agent.  This is for testing purposes only and should not be expected to work in any consistent or useful way.
-i     Use a DUID with DHCPv4 clients.  If no DUID is available in the lease file one will be constructed and saved.  The DUID will be used to construct a RFC4361 style client id that will be included in the client's messages.  This client id can be overridden by setting a client id in the configuration file.  Overriding the client id in this fashion is discouraged.
-I     Use the standard DDNS scheme from RFCs 4701 & 4702.
--decline-wait-time seconds Specify the time (in seconds) that an IPv4 client should wait after declining an address before issuing a discover.  The default is 10 seconds as recommended by RFC 2131, Section 3.1.5.  A value of zero equates to no wait at all.
--version Print version number and exit.
Options available for DHCPv6 mode:
-S     Use Information-request to get only stateless configuration parameters (i.e., without address).  This implies -6.  It also doesn't rewrite the lease database.
-T     Ask for IPv6 temporary addresses, one set per -T flag.  This implies -6 and also disables the normal address query.  See -N to restore it.
-P     Enable IPv6 prefix delegation.  This implies -6 and also disables the normal address query.  See -N to restore it.  Multiple prefixes can be requested with multiple -P flags.  Note only one requested interface is allowed.
-R     Require that responses include all of the items requested by any -N, -T, or -P options.  Normally even if the command line includes a number of these the client will be willing to accept the best lease it can even if the lease doesn't include all of the requested items.  This option causes the client to only accept leases that include all of the requested items.
Note well: enabling this may prevent the client from using any leases it receives if the servers aren't configured to supply all of the items.
-D LL or LLT Override the default when selecting the type of DUID to use.  By default, DHCPv6 dhclient creates an identifier based on the link- layer address (DUID-LL) if it is running in stateless mode (with -S, not requesting an address), or it creates an identifier based on the link-layer address plus a timestamp (DUID-LLT) if it is running in stateful mode (without -S, requesting an address). When DHCPv4 is configured to use a DUID using -i option the default is to use a DUID-LLT.  -D overrides these default, with a value of either LL or LLT.
-N     Restore normal address query for IPv6. This implies -6.  It is used to restore normal operation after using -T or -P.  Multiple addresses can be requested with multiple -N flags.
--address-prefix-len length Specify the length of the prefix for IPv6 addresses. This value is passed by dhclient into the client script via the environment variable, ip6_prefixlen, when binding IPv6 addresses.  The default value is 128.  Alternatively you may change the default at compile time by setting DHCLIENT_DEFAULT_PREFIX_LEN in includes/site.h.
--dad-wait-time seconds Specify maximum time (in seconds) that the client should wait for the duplicate address detection (DAD) to complete on an interface. This value is propagated to the dhclient script in a dad_wait_time environment variable. If any of the IPv6 addresses on the interface are tentative (DAD is in progress), the script will wait for the specified number of seconds for DAD to complete. If the script ignores this variable the parameter has no effect.
--prefix-len-hint length When used in conjunction with -P, it directs the client to use the given length to use a prefix hint of, "::/length", when requesting new prefixes.
Modifying default file locations: The following options can be used to modify the locations a client uses for its files.  They can be particularly useful if, for example, DBDIR or RUNDIR have not been mounted when the DHCP client is started.
-cf config-file Path to the client configuration file.  If unspecified, the default ETCDIR/dhclient.conf is used.  See dhclient.conf(5) for a description of this file.
-df duid-lease-file Path to a secondary lease file.  If the primary lease file doesn't contain a DUID this file will be searched.  The DUID read from the secondary will be written to the primary.  This option can be used to allow an IPv4 instance of the client to share a DUID with an IPv6 instance.  After starting one of the instances the second can be started with this option pointing to the lease file of the first instance.  There is no default.  If no file is specified no search is made for a DUID should one not be found in the main lease file.
-lf lease-file Path to the lease database file.  If unspecified, the default DBDIR/dhclient.leases is used.  See dhclient.leases(5) for a description of this file.
-pf pid-file Path to the process ID file.  If unspecified, the default RUNDIR/dhclient.pid is used.
--no-pid Option to disable writing pid files.  By default the program will write a pid file.  If the program is invoked with this option it will not attempt to kill any existing client processes even if invoked with -r or -x.
-sf script-file Path to the network configuration script invoked by dhclient when it gets a lease.  If unspecified, the default CLIENTBINDIR/dhclient-script is used.  See dhclient-script(8) for a description of this file.
During operations the client may use multiple UDP ports to provide different functions.  Which ports are opened depends on both the way you compiled your code and the configuration you supply.  The following should provide you an idea of what ports may be in use.
Normally a DHCPv4 client will open a raw UDP socket to receive and send most DHCPv4 packets.  It also opens a fallback UDP socket for use in sending unicast packets.  Normally these will both use the well known port number for BOOTPC.
For DHCPv6 the client opens a UDP socket on the well known client port and a fallback UDP socket on a random port for use in sending unicast messages.  Unlike DHCPv4 the well known socket doesn't need to be opened in raw mode.
If you have included an omapi port statement in your configuration file then the client will open a TCP socket on that port to listen for OMPAI connections.  When something connects another port will be used for the established connection.
When DDNS is enabled at compile time (see includes/site.h) the client will open both a v4 and a v6 UDP socket on random ports.  These ports are not opened unless/until the client first attempts to do an update.  If the client is not configured to do updates, the ports will never be opened.
The syntax of the dhclient.conf(5) file is discussed separately.
The DHCP client provides some ability to control it while it is running, without stopping it.  This capability is provided using OMAPI, an API for manipulating remote objects.  OMAPI clients connect to the client using TCP/IP, authenticate, and can then examine the client's current status and make changes to it.
Rather than implementing the underlying OMAPI protocol directly, user programs should use the dhcpctl API or OMAPI itself.  Dhcpctl is a wrapper that handles some of the housekeeping chores that OMAPI does not do automatically.  Dhcpctl and OMAPI are documented in dhcpctl(3) and omapi(3).  Most things you'd want to do with the client can be done directly using the omshell(1) command, rather than having to write a special program.
The control object allows you to shut the client down, releasing all leases that it holds and deleting any DNS records it may have added.  It also allows you to pause the client - this unconfigures any interfaces the client is using.  You can then restart it, which causes it to reconfigure those interfaces.  You would normally pause the client prior to going into hibernation or sleep on a laptop computer.  You would then resume it after the power comes back.  This allows PC cards to be shut down while the computer is hibernating or sleeping, and then reinitialized to their previous state once the computer comes out of hibernation or sleep.
The control object has one attribute - the state attribute.  To shut the client down, set its state attribute to 2.  It will automatically do a DHCPRELEASE.  To pause it, set its state attribute to 3.  To resume it, set its state attribute to 4.
The following environment variables may be defined to override the builtin defaults for file locations.  Note that use of the related command-line options will ignore the corresponding environment variable settings.
PATH_DHCLIENT_CONF The dhclient.conf configuration file.
PATH_DHCLIENT_DB The dhclient.leases database.
PATH_DHCLIENT_PID The dhclient PID file.
PATH_DHCLIENT_SCRIPT The dhclient-script file.
CLIENTBINDIR/dhclient-script, ETCDIR/dhclient.conf, DBDIR/dhclient.leases, RUNDIR/dhclient.pid, DBDIR/dhclient.leases~.
dhcpd(8), dhcrelay(8), dhclient-script(8), dhclient.conf(5), dhclient.leases(5), dhcp-eval(5).
dhclient(8) To learn more about Internet Systems Consortium, see https://www.isc.org
This client was substantially modified and enhanced by Elliot Poger for use on Linux while he was working on the MosquitoNet project at Stanford.
The current version owes much to Elliot's Linux enhancements, but was substantially reorganized and partially rewritten by Ted Lemon so as to use the same networking framework that the Internet Systems Consortium DHCP server uses.  Much system-specific configuration code was moved into a shell script so that as support for more operating systems is added, it will not be necessary to port and maintain system-specific configuration code to these operating systems - instead, the shell script can invoke the native tools to accomplish the same purpose.
REFLECTOR(1)                                                        REFLECTOR(1)
reflector - retrieve and filter the latest Pacman mirrorlist
reflector [arguments]
reflector is a Python script and associated Python module that can retrieve up-to-date Arch Linux mirror data from the Mirror Status (https://www.archlinux.org/mirrors/status/) web interface.
See reflector --help.
Print the latest mirrorlist to STDOUT:
Sort the five most recently synchronized mirrors by download speed and overwrite the local mirrorlist:
reflector --latest 5 --sort rate --save /etc/pacman.d/mirrorlist
Select the 200 most recently synchronized HTTP or HTTPS mirrors, sort them by download speed, and overwrite the file /etc/pacman.d/mirrorlist:
reflector --latest 200 --protocol http,https --sort rate --save /etc/pacman.d/mirrorlist
Select the HTTPS mirrors synchronized within the last 12 hours and located in either France or Germany, sort them by download speed, and overwrite the file /etc/pacman.d/mirrorlist with the results:
reflector --country France,Germany --age 12 --protocol https --sort rate --save /etc/pacman.d/mirrorlist
Reflector includes systemd service and timer units that can be used to automatically update Pacmanâ€™s mirrorlist.  To use the timer, edit the configuration file at /etc/xdg/reflector/reflector.conf and then enable the timer with
systemctl enable reflector.timer systemctl start reflector.timer
Check that status with systemctl list-timers.  To update the mirrorlist immediately instead of waiting for the scheduled operation, run systemctl start reflector.service.
Xyne.
GIT-STATUS(1)                      Git Manual                      GIT-STATUS(1)
git-status - Show the working tree status
git status [<options>...] [--] [<pathspec>...]
Displays paths that have differences between the index file and the current HEAD commit, paths that have differences between the working tree and the index file, and paths in the working tree that are not tracked by Git (and are not ignored by gitignore(5)). The first are what you would commit by running git commit; the second and third are what you could commit by running git add before running git commit.
-s, --short Give the output in the short-format.
-b, --branch Show the branch and tracking info even in short-format.
--show-stash Show the number of entries currently stashed away.
--porcelain[=<version>] Give the output in an easy-to-parse format for scripts. This is similar to the short output, but will remain stable across Git versions and regardless of user configuration. See below for details.
The version parameter is used to specify the format version. This is optional and defaults to the original version v1 format.
--long Give the output in the long-format. This is the default.
-v, --verbose In addition to the names of files that have been changed, also show the textual changes that are staged to be committed (i.e., like the output of git diff --cached). If -v is specified twice, then also show the changes in the working tree that have not yet been staged (i.e., like the output of git diff).
-u[<mode>], --untracked-files[=<mode>] Show untracked files.
The mode parameter is used to specify the handling of untracked files. It is optional: it defaults to all, and if specified, it must be stuck to the option (e.g.  -uno, but not -u no).
The possible options are:
•   no - Show no untracked files.
•   normal - Shows untracked files and directories.
•   all - Also shows individual files in untracked directories.
When -u option is not used, untracked files and directories are shown (i.e. the same as specifying normal), to help you avoid forgetting to add newly created files. Because it takes extra work to find untracked files in the filesystem, this mode may take some time in a large working tree. Consider enabling untracked cache and split index if supported (see git update-index --untracked-cache and git update-index --split-index), Otherwise you can use no to have git status return more quickly without showing untracked files.
The default can be changed using the status.showUntrackedFiles configuration variable documented in git-config(1).
--ignore-submodules[=<when>] Ignore changes to submodules when looking for changes. <when> can be either "none", "untracked", "dirty" or "all", which is the default. Using "none" will consider the submodule modified when it either contains untracked or modified files or its HEAD differs from the commit recorded in the superproject and can be used to override any settings of the ignore option in git-config(1) or gitmodules(5). When "untracked" is used submodules are not considered dirty when they only contain untracked content (but they are still scanned for modified content). Using "dirty" ignores all changes to the work tree of submodules, only changes to the commits stored in the superproject are shown (this was the behavior before 1.7.0). Using "all" hides all changes to submodules (and suppresses the output of submodule summaries when the config option status.submoduleSummary is set).
--ignored[=<mode>] Show ignored files as well.
The mode parameter is used to specify the handling of ignored files. It is optional: it defaults to traditional.
•   traditional - Shows ignored files and directories, unless --untracked-files=all is specified, in which case individual files in ignored directories are displayed.
•   no - Show no ignored files.
•   matching - Shows ignored files and directories matching an ignore pattern.
When matching mode is specified, paths that explicitly match an ignored pattern are shown. If a directory matches an ignore pattern, then it is shown, but not paths contained in the ignored directory. If a directory does not match an ignore pattern, but all contents are ignored, then the directory is not shown, but all contents are shown.
-z Terminate entries with NUL, instead of LF. This implies the --porcelain=v1 output format if no other format is given.
--column[=<options>], --no-column Display untracked files in columns. See configuration variable column.status for option syntax.  --column and --no-column without options are equivalent to always and never respectively.
--ahead-behind, --no-ahead-behind Display or do not display detailed ahead/behind counts for the branch relative to its upstream branch. Defaults to true.
--renames, --no-renames Turn on/off rename detection regardless of user configuration. See also git-diff(1) --no-renames.
--find-renames[=<n>] Turn on rename detection, optionally setting the similarity threshold. See also git-diff(1) --find-renames.
<pathspec>... See the pathspec entry in gitglossary(7).
The output from this command is designed to be used as a commit template comment. The default, long format, is designed to be human readable, verbose and descriptive. Its contents and format are subject to change at any time.
The paths mentioned in the output, unlike many other Git commands, are made relative to the current directory if you are working in a subdirectory (this is on purpose, to help cutting and pasting). See the status.relativePaths config option below.
Short Format In the short-format, the status of each path is shown as one of these forms
XY PATH XY ORIG_PATH -> PATH
where ORIG_PATH is where the renamed/copied contents came from. ORIG_PATH is only shown when the entry is renamed or copied. The XY is a two-letter status code.
The fields (including the ->) are separated from each other by a single space. If a filename contains whitespace or other nonprintable characters, that field will be quoted in the manner of a C string literal: surrounded by ASCII double quote (34) characters, and with interior special characters backslash-escaped.
There are three different types of states that are shown using this format, and each one uses the XY syntax differently:
•   When a merge is occurring and the merge was successful, or outside of a merge situation, X shows the status of the index and Y shows the status of the working tree.
•   When a merge conflict has occurred and has not yet been resolved, X and Y show the state introduced by each head of the merge, relative to the common ancestor. These paths are said to be unmerged.
•   When a path is untracked, X and Y are always the same, since they are unknown to the index.  ??  is used for untracked paths. Ignored files are not listed unless --ignored is used; if it is, ignored files are indicated by !!.
Note that the term merge here also includes rebases using the default --merge strategy, cherry-picks, and anything else using the merge machinery.
In the following table, these three classes are shown in separate sections, and these characters are used for X and Y fields for the first two sections that show tracked paths:
•   ' ' = unmodified
•   M = modified
•   T = file type changed (regular file, symbolic link or submodule)
•   A = added
•   D = deleted
•   R = renamed
•   C = copied (if config option status.renames is set to "copies")
•   U = updated but unmerged
X          Y     Meaning ------------------------------------------------- [AMD]   not updated M        [ MTD]  updated in index T        [ MTD]  type changed in index A        [ MTD]  added to index D                deleted from index R        [ MTD]  renamed in index C        [ MTD]  copied in index [MTARC]          index and work tree matches [ MTARC]    M    work tree changed since index [ MTARC]    T    type changed in work tree since index [ MTARC]    D    deleted in work tree R    renamed in work tree C    copied in work tree ------------------------------------------------- D           D    unmerged, both deleted A           U    unmerged, added by us U           D    unmerged, deleted by them U           A    unmerged, added by them D           U    unmerged, deleted by us A           A    unmerged, both added U           U    unmerged, both modified ------------------------------------------------- ?           ?    untracked !           !    ignored -------------------------------------------------
Submodules have more state and instead report M the submodule has a different HEAD than recorded in the index m the submodule has modified content ? the submodule has untracked files since modified content or untracked files in a submodule cannot be added via git add in the superproject to prepare a commit.
m and ? are applied recursively. For example if a nested submodule in a submodule contains an untracked file, this is reported as ? as well.
If -b is used the short-format status is preceded by a line
## branchname tracking info
Porcelain Format Version 1 Version 1 porcelain format is similar to the short format, but is guaranteed not to change in a backwards-incompatible way between Git versions or based on user configuration. This makes it ideal for parsing by scripts. The description of the short format above also describes the porcelain format, with a few exceptions:
1. The user’s color.status configuration is not respected; color will always be off.
2. The user’s status.relativePaths configuration is not respected; paths shown will always be relative to the repository root.
There is also an alternate -z format recommended for machine parsing. In that format, the status field is the same, but some other things change. First, the -> is omitted from rename entries and the field order is reversed (e.g from -> to becomes to from). Second, a NUL (ASCII 0) follows each filename, replacing space as a field separator and the terminating newline (but a space still separates the status field from the first filename). Third, filenames containing special characters are not specially formatted; no quoting or backslash-escaping is performed.
Any submodule changes are reported as modified M instead of m or single ?.
Porcelain Format Version 2 Version 2 format adds more detailed information about the state of the worktree and changed items. Version 2 also defines an extensible set of easy to parse optional headers.
Header lines start with "#" and are added in response to specific command line arguments. Parsers should ignore headers they don’t recognize.
Branch Headers If --branch is given, a series of header lines are printed with information about the current branch.