Linux
Next to use basic commands
Command name
basic skills
Use examples and description
CD
Change the work path
CD - (Return to the last time you stay)
AddUser
Used by root or other administrators to create new users
AddUser Student (Add User Student)
Passwd
Set user password
Passwd student (setting password for Student users)
&
Use behind other commands, it is used to notify the computer to run a certain order in the background
Netscape & (Background Launch Browser Netscape)
PS
Display the number of processes and processes running in the current system (PID)
PS AX (Display all processes of the current system and their PID)
Mount
Used to connect file systems (such as connecting optical drives, FAT partitions, etc.)
Mount / DEV / CDROM / MNT / CDROM (connecting the disc content to / cdrom)
Umount
Remove file system
Unmount / MNT / CDROM
More and Less
Browse the contents of the file, press the Q key to end
Less TXT1 (display TXT1 content)
Chown and Chgrp
Set file or directory owner
Chown User1 File (assign file to user1)
CHGRP GRP1 File (assigning the file to the GRP1 user group)
Chmod
Change file properties, attribute rules are owners identical group other users
CHMOD U X G W O R File (to the owner can be executed, the same group can be written, others can read)
GREP
Find strings in byte stream
PS AX | GREP Sendmail (Query the PID of the Sendmail program in PS AX)
Find
Used to find a file
Find / Home -Name * .cgi (Find a file with .cgi for .cgi under / home)
Kill
Used to kill a process
Usage: Kill 361 (killing process number 361)
Rpm
Manage RPM Packages
rpm -i
(Install RPM package)
Locate
Find files
Locate AddUser (listing paths with AddUser)
WHEREIS
See which directory exactly in the file
Whereis startX (getting a path to the startX command))
CHMOD and Chown album
Directive Name: Chmod
Use permission: All users
How to use: chmod [-cfvr] [--help] [--version] mode file ...
Description: Linux / UNIX file access rights are divided into three levels: file owners, groups, others. Using CHMOD how to control the file is accessed by others.
Mode: Permissions Set strings, formats are as follows: [ugoa ...] [ =] [rwxx] ...] [, ...], where
u Indicates the owner of the file.
g indicates that the owner of the file belongs to the same group (Group).
o indicates someone else.
a means that these are all.
Represents increased permissions, indicates cancellation, = indicates unique setting permissions.
R indicates that readable, W represents written, x represents executable, X represents only when the file is a subdirectory or the file has been set to be executed.
-c: If this file authority does have changed, it will display its change action.
-f: If this file is not changed, do not display an error message.
-v: Details show permission change - R: All files in the current directory are changed with the subdirectory (ie, changed one by one by hand)
--help: Display auxiliary instructions
--Version: Display version
Example:
1. Set the file file1.txt to everyone can read:
CHMOD UGO R File1.txt
2. Set the file file1.txt to everyone can read:
CHMOD A R File1.txt
3. Set the file file1.txt and file2.txt to this file owner, and it can be written with its own same group, but others cannot be written:
CHMOD UG W, O-W File1.txt File2.txt
4, set the ex1.py to only the file owner can perform:
CHMOD u x ex1.py
5. Set all the files and subdirectories in the current directory to anyone can read:
CHMOD -R A R *
6. In addition, CHMOD can also use numbers to indicate rights such as Chmod 777 file.
Grammatical: chmod abc file
Where A, B, C are each number, which represents USER, Group, and Other permissions.
R = 4, w = 2, x = 1
To RWX attribute 4 2 1 = 7;
To RW-attribute 4 2 = 6;
To R-X attribute 4 1 = 5.
Chmod a = rwx file is the same as the Chmod 777 File effect.
Chmod ug = rwx, o = x file and chmod 771 FILE effects are the same.
If you use CHMOD 4755 FileName, this program has root permissions
Directive Name: Chown
Use permission: root
How to use: chown [-cfhvr] [--help] [--version] user [: group] file ...
Description: Linux / UNIX is multi-person multi-work industry, all of which have owners. Use Chown to change the owners of the file. In general, this instruction only is used by the system administrator (root), and the general user has no permissions to change someone else's file owner, and there is no permission to change the owner of its own files to others. Only the system administrator (root) has such permissions. User: New Archive owner's user IDGroup: New Archive owner's User Group (Group) -c: If the file owner does have changed, the change action is displayed - F: If the owner cannot Do not display the error message - H: only for links (LINK), not the LINK, true pointing file -V: Display owner change - R: All files and subdirectories in current directory Perform the same owner change (ie, changed one by one by way) - Help: Display Auxiliary Description --Version: Display version
Example:
1. Set the owner of the file file1.txt to the User Group User Jessie:
Chown Jessie: Users file1.txt
2. Use the owners of all files in the current directory with the owner of the subdirectory to the user list: Lamport:
CHMOD -R LAMPORT: USERS *
