Fifth day Permission Mask Vim Editor package installation and management

One, permission mask:

For directory: Permission Mask 0022
Maximum permissions rwxrwxrwx 777 minus the permission mask three bits is the directory permission 755

For files:
Highest privilege rw rw RW 666 minus permission Mask 644

command to modify a permission mask the Umask permission mask defaults to 0022 first 0 no tube
The permission mask in the configuration file/etc/profile

Umask-s Change permission display to symbol display

After permission bit plus + proof use ACL

Supplemental text editing tools:
VI vim Emacs

Second, vim text editor

The first phase of VIM with Linux

VI keep up with the filename open File VI There are three modes
1. Command mode d Delete x delete cursor a word y copy p paste ...
Press AIO to enter edit mode a cursor after edit I before cursor edit (☆) o Change Line
ESC back to command interface

Save exit: ESC goes back to command mode and then uppercase ZZ u can be rolled back to resolve the misoperation.
Shift: Enter line edit mode: Wq Save exit: q! forced exit not saved

Phase II
Shell command line edit mode: SH return to terminal interface Ctrl D and return text

In the VI line edit mode you can invoke the operating system command command before adding!
Example:!command do not exit VI execution command

Cursor movement: (in command mode)
1. Small file four arrows can be
2. In the large text, the home line SHIFT6 is also the beginning end and Shift4 is the end
G move to the last line, 1G back to the beginning GG back to the first line, 100G can go to 100 rows
: Set Nu Sets line number

Command mode (first mode) the following edit:
x Delete single word; d$ delete cursor to line end d^ Delete cursor to beginning DG DGG Delete current cursor to first line
NDD Delete cursor down n line

Third, package installation and management

Cat/etc/redhat-release Viewing the system version
Cat/etc/oracle-release Viewing Oracle Versions

Installation steps:
1.df-h View the location of the package CD into the media file
Go to package before installation
RPM-IVH Install the software rpm-e Remove the package rpm-u uninstall the old version and reload the new
RPM-F Update only if there is no older version, the new version will not be installed

RPM-E Deleting packages
2 queries
RPM-Q Package name can only query installed packages
Rpm-qa query All packages can be used with the pipeline selector

RPM-QL add-on name to find out what the package is loaded with
RPM-QF plus file name to search for the file belongs to that package

RPM Package Public Key Management

RPM--import [RPM Package public key file]

Four, Yum

VI/ETC/YUM.REPOS.D. Repo Software configuration file

Yum/repolist All

Fifth day Permission Mask Vim Editor package installation and management