[Bird Brother Linux Video tutorial finishing]02_02_linux operating system and common commands

Common commands for Linux operating systems continue:

I.. Date: Time Management

The 1.linux system will read the current time through the RTC when it is powered on, and if the read is successful it will no longer be used, and then the operating system itself (kernel) simulates the oscillator within the system to maintain a clock, and the Windows system is every time the operating system is powered on. Is the current time that is read from the hardware clock and is set to the current system time.

2.linux has two clocks:

Hardware clock: Date or Hwclock

System clock: Clock

The 3.date command uses:

A.date +%d Show month-day-year

B.date +%y or y display year, Y-4 bit, y-2 bit

C.date +%d Display Day

D.date +%t hour minute seconds

E.date +%y-%m-%d Display Month Day

4. Modification Time:

A.date 12011113 modifies the system time

B.hwclock-w writing the system clock to the hardware

C.hwclock-s Writing hardware clocks to the system

Second, get the use of the command help:

1. Internal command: Help command

2. External command: Command--help

Three, Command manual: Manual

1.man COMMAND

A. External command: Display the command user manual

B. Internal command: Displays the shell to which the command belongs, so the internal command generally uses the help command to view the use assistance.

2.man Sub-chapters:

View section: Whatis command displays a summary of commands and the section in which you see the chapter: Man Chapter number command

A. User command: (/bin,/usr/bin,/usr/local/bin)

B. System call:

C. Library invocation:

D. Special documents: (Equipment files)

E. File format: (syntax for explaining the configuration file for a command)

F. Games:

G. Miscellaneous: Miscellaneous

H. Management Command: (/sbin,/usr/sbin,/usr/local/sbin)

3.man Chapter Description:

A.name: Command name and function brief description.

B.synopsis: Usage notes, including available options.

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

D.options: Describes the meaning of each option.

F.files: The configuration file associated with this command.

G.bugs:

H.examples: Use the example.

I.see ALSO: Another reference.

4. Flip Screen:

A. Turn back one screen: SPACE

B. Turn one screen forward: b

C. Turn back one line: ENTER

D. Turn one line forward: K

5. Find:

A./keyword: from front to back

B.? KEYWORD: from back to forward

N: Next

N: Previous

Q: Exit

Iv. online Documentation:

Info COMMAND

V. Documentation:/USR/SHARE/DOC

Six, Cal Calendar

Seven, echo default has line break

Echo-n Remove line break

ECHO-E \ n line break

Eight, printf default Start No line break, you have to manually specify \ n

IX. FILE:

Used to probe the type of a given file. File commands are divided into 3 processes: File system, Magical magic number check, and language check.

Syntax: file (option) (parameter)

-B: The file name is not displayed when the identification results are listed;

C: Detailed instruction execution process, easy to debug or analyze the execution of the program;

-f< file name;: Specify a name file whose contents have one or more file names, and let file identify the files sequentially, in the format of one file name per column;

-L: Directly displays the file categories that the symbolic link points to;

-m< Magic Digital file;: Specify magic digital file;

-V: Displays version information;

-Z: Try to interpret the contents of the compressed file.

This article is from the "Linux Blind Advanced Road" blog, please be sure to keep this source http://blindbird.blog.51cto.com/12338383/1878407

[Bird Brother Linux Video tutorial finishing]02_02_linux operating system and common commands