Learning "Linux in respect of such a study," notes quiz Lesson Seven
Instructor: Liu Trent
Chapter V user identity and file permissions
5.3 file special permissions
5.3.1 SUID SGID SBIT
hidden attribute 5.4 file
5.4.1 the chattr the lsattr
the chattr command hidden in the settings file permissions, the format is "chattr [parameters] files." If you want to add a feature to hide the files, append "+ parameters" in the command back, if you want to move files to a hidden feature, append "- parameter."
lsattr command for permission to display hidden files, the format is "lsattr [parameters] files." In the Linux system, hidden file permissions must use the lsattr command to view, usually use the ls command like you do not see the clues:
access control list file 5,5
5.5.1 setfacl getfacl
5.6 su and sudo command service
su command sudo service is
a minus sign between su command with a user name (-), which means that switching to a completely new user, that is the environment variable information is also changed to the corresponding information for new users rather than retaining the original information. It is strongly recommended to add the minus sign when switching user identity (-)
using the visudo command to configure profiles sudo command, the method is consistent with the method used Vim editor of its operation, so after their completion remember in the last line mode save and exit. Sudo command in the configuration file, the information specified on the (approximately) will be completed in accordance with the format line 99 the following:
Who can use allow the use of host = list (to whose identity) executable commands
Chapter VI storage architecture and disk partitioning
6.1 everything from "/" Start
all files from the Linux system is the "root (/)" directory to start, and using a tree structure in accordance with the file system hierarchy standard (FHS) to store files, and defines the purpose of the common directory.
In the Linux system, everything is a file, the hardware device is no exception. Since it is a file, it must have a file name. System kernel udev Device Manager will automatically name the hardware regulate them, to let the user can roughly guess device attributes and partition information by name of device files; This is especially convenient for unfamiliar equipment is. In addition, udev Device Manager service will always running and listens for signals sent by the kernel to manage the device files in the / dev directory as a daemon.
