Linux Common Commands--ls, CD, date usage

[Email protected] ~]# ls-l/etc

Total Dosage 1776

Drwxr-xr-x. 3 root root 4096 August 01:40 ABRT

Drwxr-xr-x. 4 root root 4096 August 01:44 ACPI

-rw-r--r--. 1 root root 46 September 01:31 Adjtime

-rw-r--r--. 1 root root 1512 January aliases

lrwxrwxrwx. 1 root root 22 August 01:46 grub.conf. /boot/grub/grub.conf

Ls

-L: Long format

Common file types:

-: Normal file

D: Catalog file

B: Block device files

C: Note Equipment file

L: Symbolic Link file

P: Command Pipeline file

A: Socket file

File permissions: 9-bit, per three-bit group: rwx (Read, write, execute),-Indicates no permissions

Number of times (3 4 1) After permission indicates the number of hard links to a file

Owner of File: Owners

Genus of files: group

File size, per byte

Timestamp (Timeatamp): Last Modified Time

Access Time: Access

Modified: Modify, the file content has changed

Change time: change,metadata, meta data

-H: Do unit conversions

-A: Displays all files. hidden files at the beginning also appear

. Represents the current directory

.. Represents the previous level of the directory

-A

-D Display the directory itself property

Cd:change Directory

CD ~username show a user's home directory

[Email protected] donggen]# CD ~

[Email protected] ~]# CD ~donggen

[Email protected] donggen]#

CD-Switch between the current directory and the previous directory

Environment variables: named memory space

Assigning values to variables

Name=donggen

View environment variable path: printenv

Type: Shows what type of development belongs to

Date: Time management date month day hour divided by year. Seconds Eg:date 1007201608122016.30

Clock: Check the hardware clock hwclock-w synchronize the system time to the hardware clock

The hwclock-s synchronizes the hardware clock to the system time.

Linux:rtc

Sub-chapters:

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

2. System call

3, MO User

4. Special documents (equipment files)

5. File format (configuration file syntax)

7. Miscellaneous

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

<>: Required option []: Optional ...: can appear multiple times |: Multiple selection One {}: Grouping

This article is from the "Learn Linux history" blog, please be sure to keep this source http://woyaoxuelinux.blog.51cto.com/5663865/1859052

Linux Common Commands--ls, CD, date usage