Linux commands for device management

dumpkeys
　　name: dumpkeys
　　permission: all users
　　Usage:
　　 dumpkeys [ -hilfn1 -Sshape -ccharset --help --short-info
　　 --long-info --numeric --full-table --separate-lines
　　 --shape =shape --funcs-only --keys-only --compose-only
　　 --charset=charset ]
　　Instructions for use:
　　This command is used to write the keyboard mapping table to the standard output, and the output format can be used by the loadkeys command load. The function of this table is to convert the scan code (scan code) generated by the keyboard hardware into ASCII or any string.
　　This is a Linux-specific command that allows you to convert key combinations on the keyboard, such as ctrl-a. shift-a, etc., into appropriate strings. For example, you can define alt-ctrl-f12 as "linux", and then pressing alt-ctrl-f12 is equivalent to typing the word linux.
　　To define alt-ctrl-f12 as linux, there are two things to do. First, you must define the key combination of alt-ctrl-f12 as a function key, here we use f20.
　　 control alt keycode 88 =
　　The keycode 88 above F20 is the hardware scan code of the F12 key. The next step is to define the function key F20 as linux
　　 string F20="linux"
　　will use loadkeys to load the file including these two lines, and then use alt-ctrl-f12 to input linux. Console mode Chinese systems such as chdrv and yact use this function to redefine the keyboard. Options:
　　--shortinfo, -i
　　 Display some information about the linux keyboard driver on the screen. This includes the range of hardware scan codes, the number of function keys, the number of status keys and other information.
　　--longinfo, -l Display
　　 keyboard driver information in a more detailed format.
　　--numeric, -n
　　 Use hexadecimal notation to display data. Without this option, dumpkeys will automatically convert the hexadecimal internal representation to a literal representation.
　　--full-table -f
　　 will display the entire table completely. By default, combinations that are not defined will not be displayed.
　　--seperate--lines, -1 Display a key combination in one line. In the default mode, the actions of a key under different status codes will be displayed in the same line.
　　-S,--shape=[0-3] set output format
　　0: default format (-S)
　　1: full format (--full-table)
　　2: single-line format (--seperate-lines)
　　3: Simple format, which starts with full format, but switches to single-line format after encountering the first undefined combination.
　　--funcs-only
　　--keys-only
　　--composite-only
　　 only display partial data.
　　Related commands:
　　loadkeys

loadkeys
　　name: loadkeys
　　permission: all users
　　Usage:
　　loadkeys [ -d --default ] [ -h --help ] [ -q --quiet ] [ -v --verbose [ -v -- verbose ]...] [ -m --mktable ] [ -c --clearcompose ] [ -s --clearstrings ] [ filename... ]
　　Instructions:
　　This command can change the linux keyboard driver translation according to a keyboard definition table keyboard input process. Please refer to dumpkeys for detailed instructions.
　　Options:
　　-v --verbose
　　Print verbose information, you can repeat to increase verbosity.
　　-q --quiet
　　Do not display any messages.
　　-c --clearcompose
　　clears all composite definitions.
　　-s --clearstrings
　　Clear the string definition table.
　　
　　Related command:
　　dumpkeys

MAKEDEV
　　name: MAKEDEV
　　usage:
　　MAKEDEV -V 　　MAKEDEV
　　[ -n ] [ -v ] update
　　MAKEDEV [ -n ] [ -v ] [ -d ]
　　device
All files are generated, so generally this command is not needed.

rdev
　　name: rdev
　　permission: all users
　　How to use: The basic way to use this command is: rdev [-rsvh] [-o offset] [image [value [offset]]]
　　But with the user wants to set The parameters are different, the following methods are the same:
　　rdev [ -o offset ] [ image [ root_device [ offset ] ] ]
　　swapdev [ -o offset ] [ image [ swap_device [ offset ] ] ]
　　ramsize [ -o offset ] [ image [ size [ offset ] ] ]
　　videomode [ -o offset ] [ image [ mode [ offset ] ] ]
　　rootflags [ -o offset ] [ image [ flags [ offset ] ] ]
　　Description: rdev can be used to get or set the boot kernel image file (kernel image) parameters, such as:
　　root device
　　swap device
　　RAM disk
　　video mode
　　Parameters:
　　-r
　　-s
　　-v
　　-h
　　-o
　　Example: uptime
　　The result is:
　　10:41am up 5 days, 10 min, 1 users, load average: 0.00, 0.00, 1.99

setleds
　　name : setleds
　　permission: general user
　　Usage:
　　setleds [-v] [-L] [-D] [-F] [{+|-}num] [{+|-}caps] [{+|-} scroll] Description:
　　used to set the status of the three LEDs above the keyboard. In Linux, each virtual console has its own settings.
　　Parameters:
　　-F
　　preset option, set the state of the virtual console.
　　-D
　　In addition to changing the state of the virtual console, it also changes the state of the preset.
　　-L
　　does not change the state of the virtual console, but directly changes the state of the LED display. This will make the LDE display inconsistent with the current state of the virtual console. We can restore the normal state later by using the setleds command with -L and no other options.
　　-num +num
　　Turn the number keys on or off.
　　-caps +caps
　　turns the caps key on or off.
　　-scroll +scroll
　　turns the option key on or off.
　　Example:
　　Turn on the number key and turn off the other two lights.
　　 # setleds +num -caps -scroll
　　related commands