Linux Common Commands-date-clock-hwclock-type-whois--help-man-info-cal

Date: Time management

Electronic Watch: Crystal oscillator Quartz oscillator

Linux:RTC Hardware Time

NTP: Network Time justification

Hardware Time (command:clock)

system Time (command:date)

Type command to determine whether the commands are internal or external commands

Get help with the use of commands

Internal command:

Help COMMAND

External command:

COMMAND--help

Command manual:manual

Mans COMMAND

Whatis command to see which chapter

Sub-chapters:

1. User command (/bin/usr/bin/usr/local/bin)

2. System call

3. Library users

4. Special documents (equipment files)

5. File format (configuration file syntax)

6. Games

7. Miscellaneous:(Miscellaneous)

8.Management Order (/sbin,/usr/sbin,/usr/local/sbin)

< > required

[] Optional

... can appear multiple times

| choose one More

{} Grouping

Mans

Name: command names and features brief description

Synopsis: Usage notes, including available options

DESCRIPTION: A detailed description of the command function, which may include the meaning of each option

Options: Explaining the meaning of each option

Files: The configuration file associated with this command

BUGS: Who reports Bugs to

EXAMPLES: Using the example

See ALSO: Another reference

operation after the man file is opened

Flip Screen:

Turn back one screen: Space(space bar)

Flip One screen forward:b Key

Turn back one line: Enter(enter)

Turn One line forward:K Key

Find:

/keyword Backward Lookup

? keyword forward lookup

N: Next

N: Previous

Q: Exit

Date uses

Date + "This is%Y. %n Today is%d "

UTC Green Wedge Observatory time, Prime Meridian

Greenwich Mean Time (old translation GMT or Greenwich Mean Time English: gmt prime Meridian is defined in the meridians through there. From 1924 year 2 month 5

Green Wedge Observatory's 1970 year 1 months 1 days 0 points 0 minutes 0 seconds to the current number of seconds

Hwclock-w Synchronizing system time to hardware time

Hwclock-s Synchronizing hardware time to System time

online documentation :

Info COMMAND

Document:/usr/share/doc

Cal Calendar

Cal Month calendar

Cal to specify a calendar for a year

Cal to specify a month calendar for a year

Practice

1. Echo is an internal command or an external command

2, its role?

3, How to change the line display?

Linux Common Commands-date-clock-hwclock-type-whois--help-man-info-cal