Linux Practice Command One

Usage of 1.clock and Hwclock

[Email protected] ~]# clock--help
Hwclock-query and set the hardware clock (RTC)

Usage:hwclock [function] [options ...]

Functions:
-H | --help Show this Help
-r | --show read hardware clock and print result
--set set the RTC to the time given with--date
-S | --hctosys set the system time from the hardware clock
-W | --SYSTOHC set the hardware clock to the current system time
--systz set the system time based on the current timezone
--adjust Adjust the RTC to account for systematic drift since
The clock is last set or adjusted
-C | --compare periodically compare the system clock with the CMOS clock
--getepoch print out the kernel ' s hardware clock epoch value
--setepoch set the kernel ' s hardware clock epoch value to the
Value given with--epoch
-V | --version print out the version of Hwclock to stdout

Options:
-u | --UTC the hardware clock is kept in UTC
--localtime the hardware clock is kept in local time
-F | --rtc=path special/dev/... file to use instead of default
--directisa access the ISA bus directly instead OF/DEV/RTC
--badyear Ignore RTC ' s year because the BIOS is broken
--DATE specifies the time to which to set the hardware clock
--EPOCH=YEAR Specifies the year which is the beginning of the
Hardware clock ' s epoch value
--noadjfile does not access/etc/adjtime. Requires the use of
Either--UTC or--localtime
--ADJFILE=PATH specifies the path to the "Adjust file" (Default is
/etc/adjtime)
--test do everything except actually updating the hardware
Clock or anything else
-D | --debug Debug Mode

Hwclock–s synchronizing hardware time to System time

Hwclock–w synchronizing system time to hardware time

HWCLOCK–R Display current hardware time status

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2.CD entering the specified directory

CD/skip directly to the root directory

CD etc or cd/etc into the root directory of the ETC directory before one is a relative path, the latter is an absolute path

Cd.. Return to the top level directory

3cal Bring up the calendar

CAL (1)

NAME
Cal-display a calendar

Synopsis
Cal [Options] [[[Day] month] year]

Cal Displays the current calendar

Cal year displays the calendar of the years that belong

Cal-s this month's calendar is listed by Sunday

Cal–m this month's calendar is listed by Monday

4. PWD Displays the current working directory command line under direct pwd

5. ls

NAME
Ls-list Directory Contents

Synopsis
ls [OPTION] ... [FILE] ...

Ls:list
Lists the property information for a file or directory under a specified path

Metadata: Attribute Data
Data:

ls [OPTION] ... [FILE] ...
-L: Display with long format
Drwxr-xr-x 1 root root 8 08:47. cache
D: File type
Rwxr-xr-x: Permissions, Mode
1: Number of times a file has been hard linked
Root:owner, belonging to the Lord;
Root:group, genus Group
8:size, Default is byte
23 08:47 Modify Timestamp
. cache: File name
-D: Display the directory's own properties
-h:human-readable
-A: Displays all files, including. Start hidden files
.: Current Directory
..: Parent Directory
-r:reverse, Reverse display
-r:recusive, recursive

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6.which and Whereis

Find the shell command path, but Whereis will give the Help file path

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Stat

Stat–f File Display Status

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Echo Echoing command

echo [Short-option] ... [STRING] ...
Echo long-option

DESCRIPTION
Echo the STRING (s) to standard output.

-n Do not output the trailing newline

-e enable interpretation of backslash escapes

-e Disable interpretation of backslash escapes (default)

--help Display this Help and exit

echo-e hello ' \ n ' echo Hello and let line break take effect

Echo-n Nihao does not break the line

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W Who and WhoAmI

W shows who logged in and what the system is doing

Who shows the login and login time and login address of the user logged in to the system

WhoAmI Show users logged on to the system

Shutdown,halt,poweroff System shutdown Command

Reboot System restart command

Linux Practice Command One