Linux folders and Permissions __linux

Linux folders also have three kinds of permissions, respectively: x determines whether the CD command can enter the directory, r can use the LS command to see the directory of files, W can be in the directory to create, modify, delete files, not only can modify their own files can also modify other people's files, so added a T-permission to X Permissions are restricted, indicating that only their own files can be modified.

The Umask command can set the system's permission mask, that is, you can control the default permissions for folders, file generation. The default permissions for a folder are 755, the permissions of the file 644.root account Umask is 022, and the average user's umask is 002, which means that the root user's file has less default permissions for other users. The default permissions for a file are 666 minus Umask, and the default permissions for the folder are 777 minus Umask, which means that the default permissions for files that are generated whenever they are created cannot have permissions to run. Umask settings can be set and changed in the configuration file/ETC/BASHRC.

The Linux directory is a predictable directory design. Structure of the directory:

Bin executable file, accessible to all, system must be

Executable files used by Sbin system administrators

Directory of USR user installation software The/usr/bin and/usr/sbin structures are similar to those of/bin and/sbin.

Dev settings file

Home directory is created in this directory by other users except the root user

Lib library file, dynamic library file,/lib/modules is kernel module

CDROM automatically loaded directory in Media graphics mode

MNT loaded Directory

Proc in-Memory files

var variable something like a log

Boot store grub and Lilo and kernel

ETC configuration file

INITRG empty folder, System boot required must not be less

Lostfound lost the file back to the block store.

Opt third party software installation location

The home directory of the root root user

SYS AS/proc